From owner-population-bio@net.bio.net Sat Apr 01 23:00:00 1995 Path: biosci!agate!howland.reston.ans.net!newsjunkie.ans.net!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail From: john266@aol.com (John266) Newsgroups: bionet.population-bio Subject: Re: Where can I get info on Population Growth? Date: 1 Apr 1995 22:05:57 -0500 Organization: America Online, Inc. (1-800-827-6364) Lines: 1 Sender: root@newsbf02.news.aol.com Message-ID: <3ll4al$hle@newsbf02.news.aol.com> References: Reply-To: john266@aol.com (John266) NNTP-Posting-Host: newsbf02.mail.aol.com go 'census' on YAHOO From owner-population-bio@net.bio.net Sun Apr 02 23:00:00 1995 Newsgroups: bionet.population-bio Path: biosci!agate!howland.reston.ans.net!pipex!uknet!newsfeed.ed.ac.uk!leeds.ac.uk!news From: gen5ajt@leeds.ac.uk (Adam J. Trickett) Subject: Re: Population Genetics Simulation Message-ID: Organization: University of Leeds Date: Mon, 3 Apr 1995 12:04:35 +0100 (BST) References: <3lkk6j$bre@yama.mcc.ac.uk> X-Newsreader: Trumpet for Windows [Version 1.0 Rev A] Lines: 34 In article <3lkk6j$bre@yama.mcc.ac.uk> (Nick) writes: >From: (Nick) >Subject: Population Genetics Simulation >Date: 1 Apr 1995 22:30:43 GMT >Does anyone know oif any easy simulation software to simulate >population genetics? >I'm no programmer, so a package is best. >Please reply to : ap2@bolton.ac.uk >Thanks We use Populus 3.4. It runs on IBM-PC clones, of just about any age, but in practice it prefers a 386 + with a 387 numeric co-porocessor, or above. It runs in DOS, or a DOS session from Windows, and a Windows version is due out eventually. It is freely available, contact Don Alsted at dna@ecology.ecology.umn.edu for further information. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > Adam J Trickett Voice +44 (0)-113-233-3107 > > Department of Genetics Fax +44 (0)-113-244-1175 > > University of Leeds EMail gen5ajt@leeds.ac.uk > > LEEDS LS2 9JT WWW http://www.leeds.ac.uk > > United Kingdom /genetics/resear/butlin > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > The great tragedy of science - the slaying of a > > beautiful theory by an ugly fact - T. H. Huxley > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> From owner-population-bio@net.bio.net Sun Apr 02 23:00:00 1995 Newsgroups: bionet.population-bio Path: biosci!bcm!cs.utexas.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!thdraxe From: thdraxe@netcom.com (Lawrence Oei) Subject: Populations of the world Message-ID: Organization: NETCOM On-line Communication Services (408 261-4700 guest) X-Newsreader: TIN [version 1.2 PL1] Date: Mon, 3 Apr 1995 23:29:21 GMT Lines: 3 Sender: thdraxe@netcom2.netcom.com Can somebody post the top 20 most populated cities in the world? Thanks From owner-population-bio@net.bio.net Sun Apr 02 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Human brain competes with DNA/natural selection in its coding ofcoding nature Date: 3 Apr 1995 06:25:52 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 42 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504031318.AA18815@tempest.adsnet.net> NNTP-Posting-Host: net.bio.net I propose that Garrett Hardin, while profoundly clear and informative, departs from biological objectivity briefly when he states that human society operates under natural selection (_The Limits of Altruism_). We live in times with no comparison in biological history -- the selection of human beings according to social _policies, in an age of high technology and electronic communications. "Survival of the fittest" as a biological term does not apply to a few generations or individuals. It refers to the overall trend over the span of ages -- pertaining to the rise of species and traits in species. The huge and widespread use of information other than DNA, coupled with the activity of computing (from clay tablets to neural networks), sets human selection apart from natural selection. Present human selection is not a gradual selection for "fitness" but often like an arbitrary turn of events. Huge parts of the gene pools of other social primates were seldom destroyed or thwarted all at once in nature in ages past, except in events of weather, geology or DNA (diseases). In human society, currency hoarding, ideological tribalism, and the uniqueness of the human brain, _all considered together_, are departures from familiar models of nature. Their statistical effects on population are far less related to "fitness" than previous trends of selection. And they are occurring in a context of far fewer generations as human information more and more transcends what our DNA specifically encoded. "Fitness" was never a term of approval in nature, but a term describing how nature's processes work. ( If "fitness" were a term of _approval, we would be endorsing every alligator's predation of a thwarted human ancestor, for example.) Yet human society today, even more than other primates, bases its selection on abstract ideas of "approval" as expressed in ownership of currency and hierarchical social status. But those ideas are not administered by DNA information systems as natural selection previously has been. The human brain is now coding nature as DNA and time and chance once did, and we have not yet described the context adequately. If this is correct, then even Charles Darwin would not be a "social darwinist" because "natural selection" and "survival of the fittest" pertain to effects of natural (not artificial, man-made) selection processes. Mike Pearson e5079021@tempest.adsnet.net From owner-population-bio@net.bio.net Sun Apr 02 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Improve our best public writing Date: 3 Apr 1995 06:25:39 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 48 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504031317.AA18812@tempest.adsnet.net> NNTP-Posting-Host: net.bio.net Re: pill for 3rd world On March 20, 1995, Jan Wesenberg writes: >whenever science turns from explanatory to normative, >it turns into politics (not political science, but politics). And that >politics has to be based upon various insights from several scientific >disciplines (and also upon some ladder of values provided by ideology or >politics itself) in order to be good politics. > Attempts to base politics >only upon biological insights, neglecting more humanistic insights and the >issue of values, have not been very appealing. >we should argue scientifically when appropriate and >politically when appropriate, and not try to reduce politics to science and >answer political questions with scientific answers, omitting the issue of >values. In all seriousness, your well-phrased thoughts deserve a better reply, but for now I will send this: Applying biological principles objectively to their fullest legitimate extent can provide insight which people of other disciplines, whether scientists, economists, journalists or politicians, might overlook. Yet such a project deserves perhaps five times as much scientific organization and care in assembly as most other information projects. I would propose that the books of Garrett Hardin and Paul Ehrlich, for examples, would become five times more useful if they were translated _critically_, chapter by chapter, page by page, back into biological metaphor and exactness -- and once again then translated in brief summaries back into the language of politics or mainstream literature. Yet first of all those writings should be reexamined carefully by diverse biological points of view. Nature provides the models for engineering and sociobiology, but our understanding of those models is most tenuous at the levels where many disciplines are involved. At the level of biology and human social policy, we're dealing with all the disciplines. Perhaps human society is not primarily undergoing natural selection now because "natural" has previously excluded the extensive use of the "drawing board" where experience can be abstract instead of materially costly. We have a chance now to make our mistakes on the drawing board, or to make them on the game board. That's why it's worth spending five times the effort on how well we apply biology to social issues. Mike Pearson e5079021@tempest.adsnet.net From owner-population-bio@net.bio.net Mon Apr 03 23:00:00 1995 Path: biosci!bcm!cs.utexas.edu!news.sprintlink.net!uunet!in1.uu.net!newsflash.concordia.ca!canopus.cc.umanitoba.ca!tribune.usask.ca!rover.ucs.ualberta.ca!news.bc.net!torn!ccshst05.cs.uoguelph.ca!ccshst01.cs.uoguelph.ca!jpopi From: jpopi@uoguelph.ca (Jon Popi) Newsgroups: bionet.population-bio Subject: Bootstrap procedure in maize diversity analyses Date: 4 Apr 1995 12:40:34 GMT Organization: University of Guelph Lines: 20 Message-ID: <3lreo2$k6n@ccshst05.cs.uoguelph.ca> NNTP-Posting-Host: ccshst01.cs.uoguelph.ca X-Newsreader: TIN [version 1.2 PL2] I would like to evaluate the diversity existing within and among sixteen maize populations by using RAPD analyses. What is puzzling me is the number of plants that should be analyzed per population (of course, I would like to analyze the smallest number of plants that would provide reliable results). In order to find this out, I have run RAPD analyses with ten primers on 100 plants from one of the populations (presumably the least diverse), and I would like to apply the bootstrap procedure in order to find the standard error for samples of different sizes. Does anybody know of a computer program that would perform all three steps of the Monte Carlo algorithm for the bootstrap procedure (i.e. the sampling, computation of the distance and the calculation of the standard error)? Thank you very much in advance! Jon Popi Crop Science Department University of Guelph Guelph, Ontario Canada From owner-population-bio@net.bio.net Mon Apr 03 23:00:00 1995 Newsgroups: bionet.population-bio Path: biosci!bcm!cs.utexas.edu!news.sprintlink.net!pipex!uknet!newsfeed.ed.ac.uk!leeds.ac.uk!news From: pabjmw@leeds.ac.uk (J.M. Wortley) Subject: top 20 cities Message-ID: Organization: University of Leeds Date: Tue, 4 Apr 1995 11:10:28 +0100 (BST) X-Newsreader: Trumpet for Windows [Version 1.0 Rev A] Lines: 25 These are the most recent I have (1993?), but in some cases, dN/dT is VERY large! Mexico City 19.39 New York 18 LA 13.5 Cairo 13 Shanghai 12.50 Beijing 10.7 Seoul 9.65 Calcuttta 9.2 Moscow 8.82 Paris 8.71 Sao Paulo 8.58 Tokyo 8.32 Tianjin 8.3 Bombay 8.2 Chicago 8.1 London 6.77 Jakata 6.50 Lagos 6 San Francisco 6 Manila 5.93 Jonathan Wortley, University of Leeds From owner-population-bio@net.bio.net Mon Apr 03 23:00:00 1995 Path: biosci!NETCOM.COM!gothmog From: gothmog@NETCOM.COM (En ring til aa herske) Newsgroups: bionet.population-bio Subject: Re: Bootstrap procedure in maize diversity analyses Date: 4 Apr 1995 07:57:06 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 1 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <3lreo2$k6n@ccshst05.cs.uoguelph.ca> NNTP-Posting-Host: net.bio.net Please stop email this to me!!!!! From owner-population-bio@net.bio.net Mon Apr 03 23:00:00 1995 Path: biosci!NETCOM.COM!gothmog From: gothmog@NETCOM.COM (En ring til aa herske) Newsgroups: bionet.population-bio Subject: unsubscribe population-biology Date: 4 Apr 1995 08:15:03 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 1 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <3lreo2$k6n@ccshst05.cs.uoguelph.ca> NNTP-Posting-Host: net.bio.net unsubscribe population-biology From owner-population-bio@net.bio.net Tue Apr 04 23:00:00 1995 Path: biosci!agate!sunsite.doc.ic.ac.uk!hgmp.mrc.ac.uk!daresbury!trane.uninett.no!sunic!sunic.sunet.se!umdac!news From: ablazi95@student.umu.se (Abdul Aziz Ali) Newsgroups: bionet.population-bio Subject: Re: top 20 cities Date: 5 Apr 1995 06:42:44 GMT Organization: Eco-Konsult. Lines: 52 Message-ID: <3lte54$ruu@kitten.umu.se> References: NNTP-Posting-Host: slip7.modem.umu.se X-Newsreader: WinVN 0.92.6+ In article , pabjmw@leeds.ac.uk (J.M. Wortley) says: > >These are the most recent I have (1993?), but in some cases, dN/dT is VERY >large! > >Mexico City 19.39 >New York 18 >LA 13.5 >Cairo 13 >Shanghai 12.50 >Beijing 10.7 >Seoul 9.65 >Calcuttta 9.2 >Moscow 8.82 >Paris 8.71 >Sao Paulo 8.58 >Tokyo 8.32 >Tianjin 8.3 >Bombay 8.2 >Chicago 8.1 >London 6.77 >Jakata 6.50 >Lagos 6 >San Francisco 6 >Manila 5.93 > >Jonathan Wortley, University of Leeds How many of these cities are in countries which depend on food aid from industrialised countries? A A Ali. From owner-population-bio@net.bio.net Tue Apr 04 23:00:00 1995 Path: biosci!biosci!not-for-mail From: zoo-ecophy@univ-rennes1.fr (Labo DAGUZAN ( Rennes. France )) Newsgroups: bionet.agroforestry,bionet.jobs.wanted,bionet.molbio.evolution,bionet.population-bio,bionet.women-in-bio,fr.bio.general,fr.jobs.demandes,fr.jobs.offres,sci.bio.ecology Subject: research of a marine biology laboratory for a Ph D Date: 5 Apr 1995 13:55:26 -0700 Organization: Univ. RENNES I ( FRANCE ) Lines: 5 Sender: biohelp@net.bio.net Distribution: world Message-ID: <3lut28$bsf@news.univ-rennes1.fr> NNTP-Posting-Host: net.bio.net Xref: biosci bionet.agroforestry:1452 bionet.jobs.wanted:1114 bionet.molbio.evolution:2622 bionet.population-bio:1346 bionet.women-in-bio:2426 sci.bio.ecology:9959 I would like to apply for a phD training in a marine biology of laboratory. I research a subject of genetic population. Write back to : zoo-ecophy@univ-rennes1.fr and precise HUBERT Sophie in the Subject line. Thanks for any help ... From owner-population-bio@net.bio.net Wed Apr 05 23:00:00 1995 Path: biosci!adam.cc.sunysb.edu!news.sprintlink.net!howland.reston.ans.net!news.moneng.mei.com!uwm.edu!reuter.cse.ogi.edu!cs.uoregon.edu!news.uoregon.edu!gladstone.uoregon.edu!caitlin From: Laurel Caitlin Coberly Newsgroups: bionet.population-bio Subject: Re: Human brain competes with DNA/natural selection in its coding ofcoding nature Date: Thu, 6 Apr 1995 10:02:05 -0700 Organization: University of Oregon Lines: 25 Message-ID: NNTP-Posting-Host: gladstone.uoregon.edu Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII In-Reply-To: <9504031318.AA18815@tempest.adsnet.net> First, I thought that Charles Darwin was not a social darwinist (?). I was under the impression that "Social Darwinism" was a construct, by others, to legitimacize current exploitation of negroes. Do you have the Darwin references supporting his involvement in the classification of human races into 'ancestral' or 'primitive' and 'advanced'? Second, "Survival of the Fittest" is not a scientifically acceptable term. Some of the biologists I am familiar with are irked by the use of this term because it is circular. Fitness is defined by survival and reproduction, therefore it makes no sense to say "Survival of the fittest." ie. If you do not survive to reproduction, by definition you have zero (or low if you consider kin selection) fitness. As to our abstract basis for selection (human selection for such things as wealth or social status), it is quite possible that these may be good predictors of the ability to care for offspring. Note that there is differential survival between offspring of wealthy vs. dissolute parents even in this country. Also, Social status may be correlated with other fitness characters such as health, symmetry (check the 'good gene' hypothesis, and ability to aquire resources. In suport of this, I offer that the 'Beautiful people' tend to be of high social status (there are problems with this argument--mainly causation, however, it is a viable alternative to arbitrary selection). Caitlin caitlin@oregon.uoregon.edu From owner-population-bio@net.bio.net Wed Apr 05 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Re: Human brain competes with DNA/natural selection in its coding of nature Date: 6 Apr 1995 14:35:36 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 77 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504062127.AA17246@tempest.adsnet.net> NNTP-Posting-Host: net.bio.net On April 6, Laurel Caitlin Coberly wrote: >First, I thought that Charles Darwin was not a social darwinist (?). I >was under the impression that "Social Darwinism" was a construct, by >others, to legitimacize current exploitation of negroes. Do you have the >Darwin references supporting his involvement in the classification of >human races into 'ancestral' or 'primitive' and 'advanced'? >Second, "Survival of the Fittest" is not a scientifically acceptable >term. Some of the biologists I am familiar with are irked by the use of >this term because it is circular. Fitness is defined by survival and >reproduction, therefore it makes no sense to say "Survival of the >fittest." ie. If you do not survive to reproduction, by definition you have >zero (or low if you consider kin selection) fitness. >As to our abstract basis for selection (human selection for such things >as wealth or social status), it is quite possible that these may be good >predictors of the ability to care for offspring. Note that there is >differential survival between offspring of wealthy vs. dissolute parents >even in this country. Also, Social status may be correlated with other >fitness characters such as health, symmetry (check the 'good gene' >hypothesis, and ability to aquire resources. In suport of this, I offer >that the 'Beautiful people' tend to be of high social status (there are >problems with this argument--mainly causation, however, it is a viable >alternative to arbitrary selection). >Caitlin Glad you wrote; I hope more on the way. In response . . . The principles of biology stay true for the passing of millions of years. How can we ignore the effects on human selection of a mere hundred generations of scrambled ideologies and cosmetic feature-driven genocides, perversely anti-science religions and shifting climates (ie the Sahara dried up only 2,500 years ago, causing migrations and severe stress). So complex ...the interplay of biology and human social selection. Genetics and environment both influence "assymetry," health problems and "ability to acquire resources." See to neonatal and childhood chemistry and habits, and circumstance. It's easier for a child of I.Q. 120 and family money to "acquire resources" than a child of I.Q. 130 without family money to do so. Re: the ability to care for offspring, children are not necessarily their parents' closest relatives genetically. If and when "gene therapy" becomes widely available even a few generations from now, how can natural selection be DNA based and natural, not manmade? I agree "survival of the fittest" is circular. BTW, we don't know how various smaller cosmetic gene subpools would have fared if they were not made minorities by the military slaughter of their ancestors. a.If we claim that military ability is a biological quality, it is tenuous . . . the next great plague would elevate its carrier to great status. Also past prejudices from pre-science days are still deeply rooted. And esthetics beyond health and hygiene have a strong element of shallowness, which, by the way, become circles of causation. (Please don't assume I am accusing _you of prejudice. That would be prejudice on my part . . . which I try to use sparingly ??.) As to the Darwin embarrassments . . . noone's right all the time. Indeed, people used evolution to justify exploitation, but BTW, white folks and orientals also suffer if they are used as a lifetime of cheap labor -- and they were indeed -- still are. If the rich are being naturally selected for survival, why are there so many more poor people in the world? (You can win that point if you try.) Mike Pearson e5079021@tempest.adsnet.net The deepest definition of Youth is Life as yet untouched by tragedy. -- George Santayana From owner-population-bio@net.bio.net Wed Apr 05 23:00:00 1995 Path: biosci!bcm!cs.utexas.edu!uunet!news1.digital.com!decwrl!enews.sgi.com!news.igc.apc.org!cdp!jhanson From: Jay Hanson Newsgroups: bionet.population-bio Subject: Cultural Carrying Capacity (Hardin, Message-ID: Date: Thu, 06 Apr 1995 11:14:22 -0700 (PDT) X-Gateway: notes@igc.apc.org Lines: 923 CULTURAL CARRYING CAPACITY A biological approach to human problems by Garrett Hardin Science, like all human institutions, evolves. Earlier in this century Einstein probably spoke for most of the scientists of his day when he identified the inner force that drew him to scientific work: "I believe with Schopenhauer that one of the strongest motives that lead men to art and science is [the desire to] escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own evershifting desires. A finely tempered nature longs to escape from personal life into the world of objective perception and thought" (Einstein 1935). Then came the Second World War and the Manhattan Project, culminating on 6 August 1945 with the announcement of the bombing of Hiroshima. Almost overnight scientists realized they could no longer escape becoming involved with the "crudities" of the world. In December of the same year, with Einstein's blessing, the Bulletin of the Atomic Scientists was founded to explore the human implications of scientific discoveries. From the day of its founding, this bulletin has, in the best and truest sense, been a controversial journal. Never again would the escapism of a Schopenhauer be quite so attractive to scientists. Biologists preceded the physicists in discovering the social perils of pursuing science wherever it might lead. By mid-nineteenth century it was obvious that there were overlaps between the territories claimed by biologists and theologians. Peace-lovers tried to establish a demilitarized zone between two tribes, but it didn't work. In 1925 ideological warfare broke out in Dayton, Tennessee. The legal outcome of the Scopes trial was ambiguous, though one philosopher, as late as 1982, maintained that "the evolutionists won a great moral victory" (Ruse 1982). A different conclusion was reached by the biologist and evolutionist, H. J. Muller. Thirty-four years after the trial, this Nobel laureate noted that the subject of evolution was almost entirely missing from high school biology textbooks. He concluded that, practically speaking, biologists had lost the battle in Dayton. On the centenary of the Origin of Species Muller thundered, "One hundred years without Darwinism are enough!" (Muller 1959). The next quarter of a century showed that Muller was no mere viewer-with-alarm (Nelkin 1977). During this period the "scientific creation" movement was born. Subsequent successes of the creationists were due in equal measure to their political skill and to the relative apathy of professional biologists. Finally biologists became sufficiently disturbed by what was happening to public education to fight creationists in the courts. Judge William R. Overton's detailed and thoughtful judgement against the creationists in Arkansas on 5 January 1982 foretold the end of the creationists' dominance of the public debate (Montagu 1984). That is history; but history should never be regarded as mere "water under the bridge." As Santayana said: "Those who cannot remember the past are condemned to repeat it" (Santayana 1905). For more than a century, we biologists failed to do our civic duty by bringing home to the general public the human significance of evolution through natural selection. That which we sowed by a century's near total neglect of public education, we richly reaped in the form of widespread anti-intellectualism fostered by Bible-worshipping fundamentalists. Biology abounds in insights that call for a massive restructuring of popular opinions. If the sad history of Darwinism in the agora is not to be repeated again and again, biologists must accept the responsibility of bringing their insights to the public. Among the more important biological concepts crying out for public explication today is the idea of "carrying capacity." Resistance to exploring its implications arises in part from the same source as resistance to Darwinism, as illustrated by the following quotations, one of which predates of the Origin of Species by more than two decades. From the beginning of the nineteenth century, evolution (though not natural selection) was "in the air." In 1837 Cardinal Nicholas Wiseman, perhaps the most influential Roman Catholic in England, disposed of human evolution with these words: "It is revolting to think that our noble nature should be nothing more than the perfecting of the ape's maliciousness" (Wiener and Noland 1957). Obviously the ground was well prepared for the rejection of Darwin's ideas long before he wrote his great book. Darwin's acute awareness of the opposition awaiting his theory no doubt accounted for much of his long delay in publishing the Origin. How vigorously that opposition expressed itself is well shown by the oft-told story of the Huxley-Wilber-force debate (see, interalia, Hardin 1959 and Brent 1981). Less spectacular, but no doubt more typical, was the reaction of the Victorian lady who, on hearing about Darwin's theory, expostulated: "Descended from the apes! My dear, we will hope that is not true. But if it is, let us pray that it may not become generally known!" (Dobzhansky 1955). It is natural that people committed less to truth than to the stability of society should prefer taboo to confrontation (Hardin 1978). In what follows, I shall use the term man in the generic sense, to apply to any and all members of the human species regardless of sex. When so used, man is equivalent to the Latin homo rather than vir. This usage is old-fashioned but, I think, aesthetically preferable to expository hybrids of person -- (as in personholes, an unhappy substitution for manholes). Even the most casual reading of the Bible shows that man occupies a very special place in the Judeo-Christian view of the world. Simply put, Darwin's great contribution to public thought was the idea that man is an animal. Not one in a thousand of those who reject Darwinism today do so because they have made a close study of the theory (as laid out, for instance, in any of the standard university textbooks on Darwinian evolution). On the contrary, their rejection has its roots in a highly emotional reaction to the thought that human beings are truly animals, answering to principles that govern all animals. Yet this assumption is the foundation of all biological research into the nature of Homo sapiens. The contrary assumption, as expressed by Cardinal Wiseman and the anonymous Victorian lady, can be called the hypothesis of human exemptionism, or exemptionism for short (Catton and Dunlap, 1978). The exemptionist assumes, without proof, that men (and women) are exempt from important laws that govern the behavior of other animals. Darwinians do not deny that there are some aspects in which human beings are unique among animals -- for instance, in being able to argue about evolution! But Darwinians put the burden of proof on those who make any particular claim of the uniqueness of man. At various times in the past man was said to be the only animal that could use tools, make tools, communicate with others of his kind, or conceptualize. Soon after each uniqueness was postulated some nonhuman exception was found. Desperately seeking something unique about their own species, apologists even looked for less laudable differentia. On various occasions it was claimed that man was the only animal that made war against his own kind, or that lied, or that committed murder or rape. But again, as fast as negative qualities were put forward, animal exemplars were found. In the end a few unique human abilities were found. (No other animal conjugates verbs or declines nouns.) But the kinship of man and the animals (meaning "other animals") remains a fruitful working hypothesis for biologists. This hypothesis is recommended to scholars of all persuasions as a sovereign remedy against deceptions engendered by exemptionist thinking. In the end we find that man is indeed a remarkable animal. There is no need to hamstring research at the outset by a commitment to exemptionism. CARRYING CAPACITY IN A NONHUMAN SETTING The management of herds, both wild and domesticated, rests on the concept of carrying capacity. A brief account of David R. Klein's classic study of the reindeer on an Alaskan island will serve to illustrate what carrying capacity means (Klein 1968). In 1944 some two dozen reindeer were released on St. Matthew Island where previously there had been none. Lichens were plentiful and the animals increased at an average rate of 32% per year for the next 19 years, reaching a peak of about 6,000 in the year 1963. During the heavy snows of 1963-64 almost all of the animals died, leaving a wretched herd of 41 females and 1 male, all probably sterile. It was not so much the inclement weather that devastated the herd as it was a deficiency in food resources, a deficiency that had been brought about by overgrazing. The carrying capacity of a territory is defined as the maximum number of animals that can be supported year after year without damage to the environment. After careful study Klein concluded that 5 reindeer per km2 was the carrying capacity of an unspoiled St. Matthew Island. An animal census taken in 1957 gave 4 animals per km2. A further 32% increase during the ensuing year would have brought the population to 5.3 per km2, a transgression of the carrying capacity. Had the herd been managed (which it was not), the number would have been kept somewhere near the 1957 size, below 5 per km2. In developing a policy for dealing with carrying capacity transgressions we must answer two questions: (1) How precise a figure is the stated carrying capacity? and (2) What are the consequences of transgressing the carrying capacity? CARRYING CAPACITY ESTIMATES: IMPRECISE BUT IMPORTANT There is no hope of ever making carrying capacity figures as precise as, say, the figures for chemical valence or the value of the gravitational constant. On St. Matthew Island the growth of reindeer moss is no doubt greater some summers than others. Certainly the availability of lichens is much less in winter when they must be dug out from under the snow. Then too there are secular variations in climate: the exceptionally severe winter of 1963-64 might have been part of a long-term cycle. To these variations must be added unavoidable variations in expert opinion. As a result, any particular figure for carrying capacity has a substantial element of the arbitrary in it. Should we refuse to build policy upon arguable estimates? What would happen if we ignored all estimates of carrying capacity? The short answer is disaster. Whenever a population grows beyond the carrying capacity, the environment is rapidly degraded; as a result, carrying capacity is reduced in subsequent years. Uncontrolled, the population continues to grow larger (for awhile) as the carrying capacity grows smaller. The details of transgression-disasters vary from one situation to another, but some of the consequences are extremely common. Overexploited edible plants are replaced by weeds previously rejected by the exploiting herbivores. Soil that has been laid bare is eroded away; this reduces local productivity in subsequent years. Soil turned into silt fills reservoirs and clogs irrigation systems. Loss of the rain-absorbent capability of soils produces faster runoff after rain, and more devastating floods in lower areas. These effects are especially severe when forests on steep slopes are destroyed. The consequences of systematically exceeding the carrying capacity are serious and, more often than not, irreversible even when the territory is freed of excess animals. Reversibility may be possible on a geological time scale of tens of thousands of years, but on the time scale of human history such long-term reversibility is no cause for complacency. The Tigris-Euphrates valley, ruined by mismanagement two thousand years ago, is still ruined. If ecologists were ever asked to write a new Decalogue, their First Commandment would be: Thou shalt not transgress the carrying capacity (Hardin 1976). Because transgression is so serious a matter, the conservative approach is to stay well below the best estimate of carrying capacity. Such a policy may well be viewed by profit-motivated people as a waste of resources, but this complaint has no more legitimacy than complaints against an engineer's conservative estimate of the carrying capacity of a bridge. Even if our concern is mere profit, in the long run the greatest economic gain comes from taking safety factors and carrying capacities seriously. Is it not time to change the meaning of the word conservative to take account of a new variety, the ecological conservative (Hardin 1985a)? The ecoconservative knows that time has no stop. Proflt seekers who focus too sharply on the bottom line of today's ledger book underestimate the consequences of time's arrow. To the ecologist, bottom line conservatives are not true conservatives. (Unfortunately bottom line conservatives now fill most of the positions on the White House staff.) ++++++++++++++++++++++++++++++++++++++++++++++ The ultimate goal of game management is to minimize the aggregate suffering of animals. +++++++++++++++++++++++++++++++++++++++++++++++ CAPACITY STRATEGY VERSUS SANCTITY STRATEGY When the numbers of an exploiting herd of animals shoot past the carrying capacity of their environment, what should concerned human beings do? The answer is simple: get rid of the excess fast. This is the correct answer regardless of whether we are primarily concerned with the well being of the animals themselves, or with human profits to be derived from exploiting them. Quite often the simplest and least cruel way to diminish animal numbers is to shoot the excess. This rational solution has been vigorously opposed since its espousal by Aldo Leopold in the 1930s (Flader 1974). In state after state, the public has had to be educated to see the harm that deer do to themselves when their numbers become too great. Game managers have been opposed by amateur but publicity-wise "animal lovers" (who will henceforth be referred to without quotation marks). With the best of intentions, animal lovers force state agencies to adopt remedies that inevitably lead to more animal suffering. The ill-advised measures include the following. WINTER FEEDING. The carrying capacity of the land is usually lower in winter than in summer. When a population is no longer kept under control by predators, the numbers rise until there are too many animals to survive a normal winter. The shipping of food to the herd following winter storms prevents Nature's harsh but efficacious remedy for overpopulation. When continued for several seasons, winter feeding produces too many animals even for the summer season, and the environment is subjected to year-round degradation. TRANSPLANTING. Animal lovers, like some economists (Simon 1981), cannot accept the fact that the world has limits. Whenever the media carry accounts of starving deer, someone is sure to propose that the animals be forcibly moved to other areas that, curiously, are assumed to be both suitable and underpopulated. When such experiments are carried out, the results are invariably expensive and unsatisfactory. ADOPTION. Wild horses (really feral horses) in the western United States tug strongly at the heartstrings of animal lovers. Years of political pressure, orchestrated by "Wild Horse Annie" Johnston, finally compelled Congress to pass the Wild Free-Roaming Horses and Burros Act of 1971. This act forbids private citizens or commercial enterprises to kill, capture, or harass wild equines on federal lands. Wild horses increase by about ten percent per year, which means a doubling of the population every seven years. Unfortunately, the rate of increase of the grazing lands is a negative number. Something has to give. So the Bureau of Land Management (BLM 1980) set up an "Adopt A-Horse Program" to reduce the herds in an acceptable manner. A US resident, after filling out an application form and paying $200 for a horse or $75 for a burro, can pick up and transport (at his own expense) an animal to take to his home property. If the adopter takes care of it in an approved manner for one year he can then obtain title to it. The animals are rounded up by combined ground and helicopter crews. The psychic trauma of such a roundup is presumed, without evidence or inquiry, to be less than the trauma of being shot. The cost to the government of each animal adopted, after subtracting the adoption fee collected was $400 in flscal year 1981, and $474 in fiscal year 1982 (BLM 1982). Thus is the expense of unwanted cruelty commonized (Hardin 1985b) . How many Americans have a suitable horse lot, and the money and the inclination to adopt a wild horse? The number is unknown. How fast is the number of potential adopters increasing? With continued urbanization the population of potential adopters is undoubtedly shrinking. Meanwhile the wild horse population grows at plus ten percent per year. The working of the mind of the committed animal lover is one of the wonders of nature. Light is thrown on this wonder by a statement made in Florida in 1982, when a portion of the Everglades became seriously overpopulated with deer. The state Game and Fresh Water Commission recommended that the deer population of 5,500 be reduced by killing 2,250 animals (41%). Reacting to this proposal a Florida attorney sought a court injunction to protect the lives of innocent, helpless, harmless, and otherwise happy creatures that have been placed on earth by God to be free from the torment of man." He claimed that killing any of the animals would amount to a "deprivation of the rights of the deer to live freely and peacefully on earth, according to nature's order" (Florida 1983). In other words, this attorney was extending into the animal realm the idea of the "sanctity of life" that many ethicists accept in the human realm. Ironically, this amounts to a denial of the exemptionism that is usually supported by those who reject the conclusions of biology. Curiously, the manner of the rejection is the exact opposite of that practiced by biologists: animals lovers would endow animals with the gifts usually reserved for human beings. Animal lovers and professional biologists should be able to agree on the ultimate goal of game management: to minimize the aggregate suffering of animals. They differ in their time horizons and in the focus of their immediate attention. Biologists insist that time has no stop and that we should seek to maximize the wellbeing of the herd over an indefinite period of time. To do that we must "read the landscape," looking for signs of overexploitation of the environment by a population that has grown beyond the carrying capacity. By contrast, the typical animal lover ignores the landscape while focusing on individual animals. To assert preemptive animal rights amounts to asserting the sanctity of animal life, meaning each and every individual life. Were an ecologist to use a similar rhetoric he would speak of the "sanctity of carrying capacity." By this he would mean that we must consider the needs not only of the animals in front of us today but also of unborn descendants reaching into the indefinite future. Time has no stop, the world is finite, biological reproduction is necessarily exponential: for these combined reasons the sanctity strategy as pursued by animal lovers in the long run saves fewer lives, and these at a more miserable level of existence, than does the capacity strategy pursued by ecologically knowledge able biologists. Thus do we have the paradox that the interests of an animal species are best served by focusing attention on the environment rather than the individual animals. The environment is taken as a "given," and the animal population is made to match the capacity of the environment. THE HUMAN CONTEXT: CULTURE AND CARRYING CAPACITY So far as it is within our power we surely would like to manage human populations under the ideal used for animals, namely, to minimize suffering and maximize happiness over many generations. This means that, for human populations as for others, the prime commandment must be Thou shalt not transgress the carrying capacity. Most of the principles worked out for populations of nonhuman animals apply with little change to human populations. Carrying capacity must take account of seasonal variations -- hence Aesop's story "The Ant and the Grasshopper." Long cycle secular variations may also be important (though man, the inveterate optimist, seldom takes really adequate account of future threats). And variations in expert opinion are even greater when we deal with the human situation. For nonhuman animals it seems reasonable to measure carrying capacity in terms of resources available for survival. In evaluating the human situation, however, we are not satisfied with so simple a metric. We hold that "Man does not live by bread alone." We go beyond the spiritual meaning of the Biblical quotation in distinguishing between mere existence and the good life. This distinction, like so many population-related ideas, was well understood by Malthus, who held that the density of population should be such that people could enjoy meat and a glass of wine with their dinners. Implicitly, Malthus's concept of carrying capacity included cultural factors. The good life, then, must include a reasonable (though undefined) amount of luxury food (fresh vegetables, quality meats, delicious drinks), clothing beyond that needed for mere conservation of body heat, comfortable housing, adequate transportation, space heating and cooling, electronic entertainment, vacations, etc., etc. There is no agreed upon metric to which we can reduce the various goods so that we can compare the level of living of one people with another. There is, however, a useful partial measure. and that is the units of energy used per capita year in the various countries. Periodically the United Nations publishes a measure of energy use, stated in terms of kilograms of coal equivalent per capita per annum. Consider the following figures for the year 1982: Ethiopia, 31; World, 1,823; United States, 9,431 (UN 1984). On a relative basis, setting Ethiopia equal to unity, these become: Ethiopia, 1; World, 59; United States, 304. Admittedly, many real components of the quality of life are left out of this energy measure, e.g., many aesthetic goods, interpersonal goods, and perhaps even spiritual goods. Material energy sources are, to a large extent, interconvertible as sources of material goods and facilitators of immaterial goods. Wood can be burned to cook food, burned to heat a house, or used to construct a house. Oil can cook food, heat a house, or be used to create raw materials for an artistic painting. Crude as it is, the measure of people's energy consumption at least yields a first approximation to the material quality of their life. The enjoyment of nonmaterial goods requires at least a minimum of material well-being. On this crude measure, the average inhabitant of the world is about 60 times as well off as an average Ethiopian, while Americans are more than 300 times as well off. Anyone who goes to Ethiopia and tries to live the life of an average Ethiopian will conclude that these flgures cannot be far wrong. Carrying capacity is inversely related to the quality of life. When dealing with human beings there is no unique figure for carrying capacity. So when a pronatalist asserts (Revelle 1974) that the world can easily support 40 to 50 billion people -- some ten times the present population -- he need not be contradicted. If everyone lived on the energy budget of the Ethiopians, the earth might support 60 times the present population, or about 300 billion people. The figure just given is only a crude estimate. In less hospitable regions, e.g., in Lappland, energy must be used to produce more clothing or space heating. In the Imperial Valley of California, energy must be used for the importation and pumping of water. But such facts are no more than the details that would be needed to refine the estimate of the maximum possible population supportable by the earth -- if such an estimate is worth refining, which is doubtful. In the physical sciences the most basic terms stand for entities that are "conserved under transformations," that is for entities that remain quantitatively the same when qualitatively changed. Mass and energy are such conservative concepts. Without conservative concepts intellectual anarchy takes over and analysis becomes impossible. In bioeconomics carrying capacity plays a conservative role. In the nonhuman world its application presents few problems. Carrying capacity does not vary without cause; it does not increase in response to need; it cannot be transgressed with impunity; and its definition in particular circumstances presents no serious problem to the well-informed. Such is the situation so long as we deal only with nonhuman populations. When we move to human populations, however, the situation changes. The naive question, "What is the human carrying capacity of the earth?" evokes a reply that is of no human use. No thoughtful person is willing to assume that mere animal survival is acceptable when the animal is Homo sapiens. We want to know what the environment will carry in the way of cultural amenities, where the word culture is taken in the anthropological sense to include all of the artifacts of human existence: institutions, buildings, customs, inventions, knowledge. Energy consumption is a crude measure of the involvement of culture. It may not be the best measure possible, but it will do for a first approach. When dealing with human problems, I propose that we abandon the term carrying capacity in favor of cultural carrying capacity or, more briefly cultural capacity. As defined, the cultural capacity of a territory will always be less than its carrying capacity (in the simple animal sense). Cultural capacity is inversely related to the (material) quality of life presumed. Arguments about the proper cultural capacity revolve around our expectations for the quality of life. Given fixed resources and well-defined values, cultural capacity, like its parent carrying capacity, is a conservative concept. ECONOMISTS AND ECOLOGISTS IN CONFLICT Suppose resources are not fixed? If by resources we mean natural resources that are available for human use at a particular time, at a particular stage in technological development, then resources have not been firmly fixed during all of human history. The past two centuries have seen the most spectacular increase in the resources actually available for human use. Malthus, because he was not acutely aware of the increase in carrying capacity going on in his time, was so unlucky as to put forth a theory of population that was too static to suit the economists of subsequent times, who are keenly aware of the effect of technology on the resources effectively available to the human species. A careful reading of Malthus's work shows that he described what we would now call a cybernetic system in which negative (or corrective) feedbacks keep the population fluctuating about a relatively fixed set point (Hardin and Bajema 1978). The set point is, of course, the carrying capacity of the environment. Unfortunately for Malthus's reputation, the spectacular development of technology in the years after 1798 moved the set point steadily upward. Biologists find no difficulty in fitting this new fact into the Malthusian cybernetic scheme, but many economists and other social scientists see the continued increase in available resources as incompatible with Malthusian theory. The difference in opinion is closely connected with a difference in the perception of time (Hardin 1985b). Economics, the handmaiden of business, is daily concerned with "discounting the future," a mathematical operation that, under high rates of interest, has the effect of making the future beyond a very few years essentially disappear from rational calculation. Told that petroleum resources will, for all practical purposes, be exhausted in 20 years, the biologist starts to worry, while the economist merely yawns. For most economic planning, the ultimate horizon of time is only five years away. The economist can give two rather telling arguments for continuing to refuse to take seriously any predictions of the state of the world more than five years from now. First, for more than two centuries science has come up with one miracle after another, steadily increasing the functional carrying capacity of the world. WHY SHOULD SCIENCE NOT CONTINUE TO DO SO? Scientists see less of the miraculous in the development of technology. I am afraid that many economists see "Science-and-Technology" as a magician with a bottomless hat out of which an endless series of rabbits can be pulled. Economists have difficulty taking energy shortages seriously. They say: "First we had wood for fuel. As that became exhausted, we found we could use coal. Before that became exhausted, we discovered oil. As we began to worry about the supply of that, we discovered atomic energy. It looks like atomic energy is inexhaustible; but if it isn't, why worry? Scientists will discover something else; and just in time, as they always have in the past." Such faith may be heartwarming, but it is also dangerous. Economists have advanced another excuse for never worrying (Simon 1981), which is rather subtle and more difficult to deal with. Quoting Aesop, they maintain that "Necessity is the mother of invention." This is certainly at least a half-truth. But some economists go on to imply that the greater the necessity, the greater the inventiveness. This may be seriously doubted. In our time, necessity is greatest in wretchedly poor countries like Bangladesh and Ethiopia; but is inventiveness at its maximum in such poor countries? Certainly not. The stimulus of necessity is most effective when the standard of living includes a considerable surplus of resources (luxury) available for investment in the chancey activities of investigation, invention, and testing. Put another way, when the scale of living falls so far below the cultural carrying capacity as to preclude effective inventiveness -- when the cultural capacity is seriously transgressed -- then living conditions spiral downward as the good life degenerates into mere existence sans inventiveness. Translated into human terms, the ecological first commandment becomes: Thou shalt not transgress the cultural capacity. ONE WORLD OR MANY? To whom is the first commandment of ecology addressed: to the whole world acting as a unit, or to subdivisions of the world? Is it wise to hope and plan for One World, a world without borders? Or must our plans assume the continuation of subdivisions something like the nations we now know? This is perhaps the most fundamental political question of our time. The insights of biology are needed to solve it. The dream of One World has ancient roots. Buddha, born more than half a millennium before Christ, took a universalist position. He seems to have had little direct influence on the development of Western thought. Diogenes, in the fourth century BC, rejected mere patriotism, calling himself kosmopolites, a citizen of the world. Zeno of Citium, in the next century, committed Stoicism to the same ideal. Christianity apparently derived this universal ideal from the Stoics. Though parishes developed as a valuable administrative unit of the church, the guiding ideal of Christianity has departed more and more from parochialism (L. parochia, diocese or parish). During the past century the production of literature extolling One World has been a "growth industry." For this there are two reasons, one good and one bad (or at any rate, insufficient). The good reason has its roots in the consequences of the growth of population and technology. Population growth shrinks the regions between competing sovereignties and brings us every day closer to "living in each other's pockets." Technology, ever more puissant in both war and peace, exacerbates the consequences of propinquity. The mounting dangers of such commonized disasters as acid rain, the greenhouse effect, and the nuclear winter make anybody's business everybody's business. A purely localized solution to such problems is no solution at all. When it comes to the commons of water and air, we truly live in One World, whether or not we are clever enough to make the appropriate political adjustments. The insufficient reason for the decline of parochialism in our time arises from a philosophical error. Wealth comes in only three forms: matter, energy, and information. The first two forms obey conservation laws: their exchanges are of the zero-sum sort. What Peter gains, Paul loses. When it comes to material wealth, selective forces operate against generosity and in favor of self-interest. By contrast, exchanges of information are not bound by conservation principles: positive-sum outcomes are possible. The information that Peter gives to Paul does not make Peter the poorer. Moreover, Paul may operate on that information, later handing it back to Peter in improved form. That's a plus-sum relationship. Within limits, selection favors cautious generosity and disfavors extreme selfishness when it comes to the wealth of information. Other things equal, when it comes to the distribution of information, a world without borders should be a richer world than one divided into tight-lipped parishes. Nowhere has the rejection of parochialism been stronger than in the world of science and scholarship generally. Those who deal primarily with ideas may quite unconsciously generalize the plus-sum property of information exchanges into the domains of matter and energy, where it does not apply. It is not uncommon for dealers in information to naively suppose that Karl Marx's "From each according to his ability, to each according to his needs" (Marx 1972) is a wise rule to follow in exchanges involving matter and energy (as well as information). I believe I have shown in "The Tragedy of the Commons" (Hardin 1968) that the promiscuous sharing of matter and energy leads to universal ruin. The argument may be restated in new and more biological terms. If discrete entities (nations, for example) are in reality competing for scarce resources, those entities that follow Marx's ideal will be at a competitive disadvantage competing with more self-seeking entities. The selective value of Marx's ideal is negative, so long as the number of administrative entities is greater than one. But what if there is only one administrative unit? What if we succeed in creating the One World yearned for by Christians, Marxists, and countless other groups? Never mind that many keen minds have regarded this possibility as being highly improbable. What if...? Bertrand Russell has given the answer. To survive as a cohesive unit, an entity must be held together by some sort of cohesive force. Says Russell: "Always when we pass beyond the limits of the family it is the external enemy which supplies the cohesive force....A world state, if it were firmly established, would have no enemies to fear, and would therefore be in danger of breaking down through lack of cohesive force" (Russell 1949). The writers of science fiction have long been aware of this, repeatedly creating a scenario that brings the nations of the world into a genuine union through the threat of enemies from outer space. Unfortunately, all experience with space, to date, has given us no hope of discovering such enemies. So the problem One World or Many? remains with us. I have argued elsewhere (Hardin 1982) that no single way will suffice to administer the affairs of what some people call "Spaceship Earth." There must be some sort of fragmentation of administrative tasks, though a universal approach is needed for the protection of the commons of air and water. But most material wealth is, after all, fragmented around the world; parochial distribution calls for parochial controls. This logical necessity meshes well with the territorial instincts that have been selected for during millions of years of biological evolution. How the necessary "mixed economy" of administration is to be created and sustained is an enormous problem. In the meantime, whether or not we discover how to administer the commons of air and water, we must clarify our thoughts about the impact of competitive living on cultural carrying capacities. As before, let us allow per capita energy use to deputize for the total standard of living. This is an oversimplification of the real world, but the consequences deduced are general and would hold up under a more thorough analysis. In making comparisons of one group of people with another it is difficult to attain objectivity, because we are one of the world's groups and we have varying relations with all the others. It will help, I think, if we use the intellectual device of the "man from Mars," the observer who can be perfectly objective about earthly affairs because he has no terrestrial ties. The man from Mars makes a tour of the earth and notes the widely varying standards of living and the widely varying densities of population. He also notes that resources vary widely in their distribution. Having evolved by natural selection on Mars -- is there any other way to evolve? -- our martian (like earthlings) has strong territorial feelings. He points out that a parochial distribution of resources should be matched by parochial consumption. This general principle does not preclude international trade when a particular resource is in very short supply in a particular nation; by trading parts of their relative surpluses, trading nations can mutually gain. The per capita consumption of energy in Bangladesh is one thirty-eighth as great as the world average. Spokesmen for the country complain about this low energy income. (The material quality of life, however measured, seems correspondingly low.) How should others react to this discrepancy? The standard earthly response is to say, "Bangladesh suffers from shortages." Thus do earthlings demonstrate their fellow-feeling for the Bangladeshi, even though this may be the only way they do so. But what would the man from Mars say? Being under no felt necessity to demonstrate fellow-feeling, he might well respond thus: "Shortage, you say? Shortage of resources? If parochial resources are being fully used, how can there be a shortage? Parochial demand should match parochial supply. Why not say there is a longage in demand? Though it may not be possible to increase supply, it is always possible to decrease demand. You do this either by reducing people's expectations, or by reducing the number of people who have expectations -- which can always be done by reducing the birth rate. (There is no necessity to increase the death rate.)" Continuing, the man from Mars says: "If each Bangladeshi enjoys only one thirty-eighth as much energy as the average earthling, maybe there are 38 times too many people living in Bangladesh? Should we not speak of a 'longage' of people, rather than a shortage of resources? In principle, a longage is always soluble; a shortage may not be." If Bangladesh reduced its present population of 104 million people by a factor of 38 it would have only 2.7 million people. It is of interest to note that the state of Iowa has exactly the same area as Bangladesh, but with only 2.9 million people. There are many significant differences between the two areas, so not too much should be made of the contrast in population. But the equivalence does show that the suggested population for Bangladesh is not terribly unreasonable. Adopting the martian principle that parochial demands should match parochial supplies would eliminate one important excuse for aggressive international actions. Implicitly thinking in One World terms easily leads to the concept of poor or "have-not" nations. An excessive passion for justice can then easily lead to the assertion that being poor justifies corrective military action. In our thermonuclear world, is there any justice that would justify embarking on an uncontrollable war? By contrast, the carrying capacity approach results in replacing the concept of a "have-not" nation with that of an "overpopulation" nation. It's a rare piece of property that cannot support a suitably small population in comfort. This does not mean that every territory will have a helping of all the amenities of life: people who live in Spitzbergen should not assert their right to tropical beaches, nor people in Bali their right to skiing. The exceptional property that cannot meet a minimum standard for human existence should have a zero population. It makes no sense to say that every territory has a right to be occupied by a human population. Some wretched territories now inhabited should be abandoned. Overpopulation can be corrected by means short of homicide and war. The means is attrition, which means seeing to it that the birth rate falls below the death rate (Hardin 1985b). This may be painful, but it is not war. For members of the Western world, part of the pain of adjustment of population to reality arises from the necessity of reexamining and substantially modifying our concept of human rights. In this reexamination, the deep concept of cultural carrying capacity must play a central role. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Garrett Hardin, professor emeritus of human ecology at the University of California, Santa Barbara, received the 1986 AIBS Distinguished Service Award for his contributions in the field of ecology and his long-time efforts to apply scientific methods to the ethical and political dilemmas posed by population growth and resource depletion. This is the text of his acceptance speech, given 10 August 1986 at the AIBS Annual Meeting at the University of Massachusetts, Amherst. References cited Brent, P. 1981. Charles Darwin, SA Man of Enlarged Curiosity." Harper & Row, New York. Bureau of Land Management (BLM). 1980. Our Public Lands (Special issue devoted to wild horses and burros) 30: 3-22. 1982. WildHorse &Burro Report. May, p.4. Catton, W.R., Jr., and R.E. Dunlap. 1978. Environmental sociology: a new paradigm. Am. Sociol. 13: 14-49. Dobzhansky, T. 1955. Evolution. Genetics and Man. John Wiley & Sons, New York. Einstein, A. 1935. The World As I See It. John Lane and Bodley Head, London. Flader, S.L. 1974. Thinking Like a Mountain. University of Missouri Press, Columbia. Florida, State of. 1983. Everglades Emergency Deer Hunt Controversy. Florida Game and Fresh Water Fish Commission, Tallahassee. Hardin, G. 1959. Nature and Man's Fate. Holt, Rinehart & Winston, New York. 1968. The tragedy of the commons. Science 162: 1243-1248. 1976. Carrying capacity as an ethical concept. Soundings 59: 120- 137. 1978. Stalking the Wild Taboo, 2nd ed. W.H. Freeman, San Francisco. 1982. Discriminating altruisms. Zygon 17: 163- 186. 1985a. Human ecology: the subversive, conservative science. Am. Zool. 25:469-476. 1985b. Filters Against Folly: How to Survive Despite Economists. Ecologists, and the Merely Eloquent. Viking Penguin, New York. Hardin, G., and C. Bajema. 1978. Biology: Its Principles and Implications. 3rd ed. W.H. Freeman, San Francisco. Klein, D.R.1968. The introduction, increase, and crash of reindeer on St. Matthew Island. J. Wildl. Manage. 32: 350-367. Marx, K. 1972. Critique of the Gotha program. Pages 382-398 in R. C . Tucker, ed. The Marx Engels Reader. W.W. Norton, New York. Montagu, A., ed. 1984. Science and Creationism. Oxford University Press, New York. Muller, H.J. 1959. One hundred years without Darwinism are enough. School Sci. Math. 59: 304. Nelkin, D. 1977. Science Textbook Controversies and Politics of Equal Time. MIT Press, Cambridge, MA. Revelle, R. 1974. Food and population. Sci. Am. 231: 161-170. Ruse, M. 1982. Darwinism Defended: A Guide to the Evolution Controversies. Addison-Wesley Publ. Co., Reading, MA. Russell, B. 1949. Authority and the Individual. Unwin Books, London. Santayana, G. 1905. Flux and constancy in human nature. Page 284 in The Life of Reason, 2nd ed. Scribner's, New York. Simon, J .1981. The Ultimate Resource. Princeton University Press, Princeton, NJ. United Nations (UN) 1984. Statistical Yearbook, 1982. United Nations, New York. Wiener, P.P., and A. Noland, eds. 1957. Roots of Scientific Thought. Basic Books, New York. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Carrying Capacity Network . FOCUS/Volume 2, No. 3, 1992 Carrying Capacity Network 1325 G Street, NW Suite 1003 Washington, DC 20005 Phone: 800-466-4866 or 202-879-3044 FAX: 202-296-4609 E-MAIL CCN@IGC.APC.ORG From owner-population-bio@net.bio.net Wed Apr 05 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: "Take home" messages on population trends Date: 6 Apr 1995 14:35:47 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 60 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504062128.AA17252@tempest.adsnet.net> NNTP-Posting-Host: net.bio.net TAKE-HOME MESSAGES: Ideas to keep in mind in discussing the future, from Paul and Ann Ehrlich's 1990 book, _The Population Explosion._ (Pages 237-239) "Only a mass movement can solve the population/resource/environment crisis before it overwhelms us." - The 1990 population of Earth is over 5.3 billion people, and some 95 million are being added yearly. - Unprecedented overpopulation and continuing population growth are making substantial contributions to the destruction of Earth's life-support systems. - Overpopulation is a major factor in problems as diverse as African famines, global warming, acid rain, the threat of nuclear war, the garbage crises, and the danger of epidemics. - Rapid population growth in rich countries is, from the standpoint of Earth's habitibility, more serious than rapid population growth in poor countries. - Rapid population growth in poor nations is an important reason they stay poor, and overpopulation in those nations will greatly increase their destructive impact on the environment as they struggle to develop. - There is no question that the population explosion will end soon. What remains in doubt is whether the end will come humanely because birthrates have been lowered, or tragically through rises in death rates. - Anyone who opposes controlling the number of births is unknowingly promoting more premature deaths. - Earth cannot long sustain even 5.3 billion people with foreseeable technologies and patterns of human behavior. If civilization is to survive, population _shrinkage below today's size will eventually be necessary. - Population control is the most pressing of human problems because of the enormous lag time between beginning an effective program and starting population shrinkage. - A maximum number of people will live eventually if the population is reduced to a sustainable size and maintained for millions of years. Trying to see how many can live all at once is a recipe for a population crash that will lower Earth's carrying capacity and reduce the number of people that can ever exist. - The population/resource/environment predicament was created by human actions, and it can be solved by human actions. All that is required is the political and societal will. The good news is that, when the time is ripe, society can change its attitudes and behavior rapidly. - We must all tithe to society in order to ripen the time. Mike Pearson e5079021@tempest.adsnet.net The deepest definition of Youth is Life as yet untouched by tragedy. -- George Santayana From owner-population-bio@net.bio.net Thu Apr 06 23:00:00 1995 Newsgroups: bionet.population-bio,comp.ai.neural-nets,bionet.plants Path: biosci!bcm!cs.utexas.edu!howland.reston.ans.net!news.sprintlink.net!uunet!in1.uu.net!gail.ripco.com!inquire From: inquire@ripco.com (Resampling Stats) Subject: If you teach statistics (P04065d) Message-ID: Followup: poster Sender: usenet@rci.ripco.com (Net News Admin) Organization: Ripco Internet BBS Chicago X-Newsreader: TIN [version 1.2 PL2] Date: Fri, 7 Apr 1995 02:43:04 GMT Lines: 27 Xref: biosci bionet.population-bio:1353 comp.ai.neural-nets:14394 bionet.plants:6332 WITH RESAMPLING: STUDENTS LEARN MORE, ENJOY COURSE As far back as the 1970's, controlled experiments found better classroom results with the "new statistics" - the resampling method - than with conventional methods. Students handle more problems correctly and like statistics much better with resampling than with conventional methods. At sites ranging from Frederick Junior College to Stanford University Graduate School, recent surveys of student judgments of courses using the resampling method - including both introductory and graduate classes - show that students recommend the method. Followup surveys of introductory students taught both resampling and conventional statistics show a clear advantage for resampling in amount learned, amount retained, and likelihood to use statistics in personal or work life. For a preprint with full description and data, please reply with your email and full regular mail address ("snail-mail"). Peter Bruce Resampling Stats phone 703-522-2713 612 N. Jackson St. fax 703-522-5846 Arlington, VA 22201 inquire@ripco.com USA From owner-population-bio@net.bio.net Thu Apr 06 23:00:00 1995 Path: biosci!EFN.ORG!tlea From: tlea@EFN.ORG (Tom Lea) Newsgroups: bionet.population-bio Subject: unsubscribe pop-bio@net.bio.net Date: 6 Apr 1995 20:33:55 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 1 Sender: daemon@net.bio.net Distribution: world Message-ID: NNTP-Posting-Host: net.bio.net Unsubscribe. From owner-population-bio@net.bio.net Thu Apr 06 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: An "unauthorized" shorter version of "Cultural Carrying Capacity" Date: 6 Apr 1995 19:42:28 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 115 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504070234.AA19000@tempest.adsnet.net> NNTP-Posting-Host: net.bio.net I did not ask permission of the author, though I respect him immensely, to offer this _condensation_ of: CULTURAL CARRYING CAPACITY A biological approach to human problems by Garrett Hardin Main concepts: 1) carrying capacity 2) cultural carrying capacity Science is a lovely state of mind to experience, as early scientists found. But, scientists have been pressed into service and must explain science to the public. Biologists and theologians often disagree. Fifty years after the 1925 Scopes trial, most school kids still weren't learning evolution. Finally, biologists challenged creationism in court and began to win. Biologists didn't educate the public as well as they might have in the century-plus since Darwin. If the public really understood biology, especially "carrying capacity," they would make better decisions. Not one in a thousand who reject Darwinism has really studied it closely from a standard textbook. Instead, emotion moves them. Church leaders often rejected evolution with distaste. Darwin had suspected they would. Those who did believe in evolution sometimes believed in a version with shameful overtones. Humans do a few things no animal does. But most human behaviors are also found in at least one other animal. "Carrying capacity" is defined as a stable number of animals that can be supported year after year without damaging the environment. Whenever a population grows beyond the carrying capacity, the environment is rapidly degraded; as a result, carrying capacity is reduced in subsequent years. Even if we don't know the exact "carrying capacity" of an area, we know there is a limit, and we should manage with that limit in mind. Often irreversible on a human time-scale, the common results of exceeding the carrying capacity include: Overexploited plants are replaced by weeds. Soil is laid bare and then erodes away. Productivity is reduced. More floods occur. The First Commandment of Ecology might be: "Thou shalt not transgress the carrying capacity (Hardin 1976)(Heck, this whole summary is directly from Hardin, as the title says) By keeping this commandment, economic gain and profit can thereby be managed to their maximum. A "conservative" ought to appreciate this. The bottom line of one day's ledger book is not a true guide. Unfortunately, many "bottom line" conservatives have been in power. Though there was much opposition, this commandment also minimizes cruelty to animals such as deer. Rather than letting them shoot past their carrying capacity and then starve while ruining their range, it is sometimes better to shoot the excess, as Aldo Leopold advocated in the 1930s. People who opposed shooting so many deer, or in another case, wild horses, gradually understood this idea after being educated. But animal lovers still sometimes force state agencies to resort instead to winter feeding, transplanting, and rather expensive adoption as the only acceptable policies. In the long run, the herd's environment will be degraded by the overpopulation. And even more animals will suffer than if the herd had been thinned, because biological reproduction is exponential. While animal lovers point to the "sanctity of life," the ecologist points to the "sanctity of carrying capacity," and must read the landscape and consider the good for unborn descendants. Managing human population surely calls for a different strategy to minimize suffering and maximize happiness over many generations. But the principles are the same, including the first commandment of ecology. One difference is that many believe in managing for the "good life" for all, and not just survival. One crude way to compare living standards is the units of energy used per capita year in each country. In 1982 the UN reported the United States used 50 times as much energy per person as the world average. If we figure carrying capacity with the energy figure for the poorest country, that shows the world could support many more people than if we want to support everyone at the level of the United States. Carrying capacity is basic to ecology. Without it, discussion is anarchy. For human purposes, "cultural carrying capacity" is basic, and depends on expectations for quality of life. Cultural carrying capacity is inversely related to material quality of life presumed. Scientists, being closer to the source of technology, are more pessimistic than economists about technology's ability to forever continue to increase the carrying capacity of the world. Economists have the comfort of seeing that science has always accomplished that feat in the past. Such faith is dangerous. Economists and ecologists are in conflict, because economists and other social scientists expect available resources to increase essentially forever. To help business, they calculate only a few years into the future. The ecologist worries farther into the future. The whole One World will continue to experience the side effects of technology such as pollution. Matter, energy and information are the only kinds of wealth. Information does not decrease in one's possession upon giving it to another, unlike matter and energy. A "One World" universal approach is needed for protection of the commons of air and water. However, a fragmentation of administrative tasks is necessary for most human affairs in the world. If shortages exist in some countries, the carrying capacity is being exceeded, and the shortages should be met by population shrinkage through attrition -- seeing that birth rate falls below death rate (without hurrying the latter). Human rights must be seen in the light of carrying capacity. From owner-population-bio@net.bio.net Sat Apr 08 23:00:00 1995 Path: biosci!newshost.lanl.gov!news.ttu.edu!seas.smu.edu!convex!insosf1.infonet.net!solaris.cc.vt.edu!news.duke.edu!agate!howland.reston.ans.net!newsserver.jvnc.net!paperboy.uconn.edu!paperboy.uconn.edu!kent From: kent@darwin.darwin.eeb.uconn.edu (Kent Holsinger) Newsgroups: bionet.population-bio Subject: Lecturers - University of Connecticut, Ecology & Evolution Date: 08 Apr 1995 14:10:41 GMT Organization: Dept. of Ecology & Evolutionary Biology, University of Connecticut Lines: 40 Message-ID: Reply-To: Kent@Darwin.EEB.UConn.Edu NNTP-Posting-Host: darwin.eeb.uconn.edu Lecturers University of Connecticut Ecology and Evolutionary Biology The Department of Ecology and Evolutionary Biology seeks applicants for two one-year Lecturer positions on the main campus at Storrs, beginning September 1995: (1) Animal Physiological Ecologist to teach Physiological Ecology and another course as appropriate to applicant's expertise; (2) Evolutionary Biologist with emphasis on macroevolution, paleontology, or paleobotany, to teach Evolutionary Biology and another course. Total teaching load for each position is one course per semester. Salary is $30,000 for nine months with full health benefits. A small fund for research supplies will be provided. Send curriculum vitae, statement of teaching and research interests, reprints, and three letters of recommendation to: Dr. Kentwood D. Wells, Acting Head Department of Ecology and Evolutionary Biology University of Connecticut, U-43 75 N. Eagleville Road Storrs, CT 06269-3043 e-mail: Kentus@UConnVM.UConn.Edu Screening of applicants will begin April 15, 1995 and continue until the positions are filled. We encourage applications from underrepresented groups, including minorities, women, and people with disabilities. Search #5A286 & 5A287 -- ------------------------------- Kent E. Holsinger Department of Ecology & Evolutionary Biology University of Connecticut, U-43 Storrs, CT 06269-3043 From owner-population-bio@net.bio.net Mon Apr 10 23:00:00 1995 Path: biosci!rutgers!gatech!news-feed-1.peachnet.edu!usenet.eel.ufl.edu!usenet.cis.ufl.edu!usenet.ufl.edu!usenet From: "A. F. Cockburn" Newsgroups: bionet.population-bio,bionet.molbio.evolution Subject: mtDNA variability within a species Date: 11 Apr 1995 12:34:38 GMT Organization: University of Florida Lines: 17 Message-ID: <3mdt0u$lb0@no-names.nerdc.ufl.edu> NNTP-Posting-Host: ppp-20-nerdc-ts1.nerdc.ufl.edu Xref: biosci bionet.population-bio:1355 bionet.molbio.evolution:2656 Hello all, I was wondering what the largest distance was that had been measured between haplotypes within a species. We have looked at lots of mosquito haplotypes using restriction digestion and find variability is generally around 1% (in nucleotide substitutions) and almost never more than 5%. Would two haplotypes that differed by 10% be unlikely to come from the same species? I am most interested in hearing about other insects, but any animal information would be useful. Thanks, Andrew Cockburn From owner-population-bio@net.bio.net Mon Apr 10 23:00:00 1995 Path: biosci!agate!fromthe.hip.berkeley.edu!user From: reymie@uclink2.berkeley.edu (Reymie Ramirez) Newsgroups: bionet.population-bio Subject: survey for people with disability Date: Tue, 11 Apr 1995 12:39:28 -0500 Organization: UC Berkeley Lines: 5 Message-ID: NNTP-Posting-Host: fromthe.hip.berkeley.edu Sorry for listing this in a newsgroup that may not be appropriate but I am new at postings. I represent a company that is currently looking for persons with disabilities to do a survey. The company is Berkeley Planning Associates and it is a social policy research firm. For more info or to receive the survey please call 510-465-7884 or fax 510-465-7885. From owner-population-bio@net.bio.net Wed Apr 12 23:00:00 1995 Path: biosci!daresbury!trane.uninett.no!nac.no!Norway.EU.net!EU.net!howland.reston.ans.net!torn!nott!nrcnet0.nrc.ca!ratilal From: Peter Turney Newsgroups: bionet.population-bio Subject: CFP: special issue of Evolutionary Computation Date: 13 Apr 1995 17:39:33 GMT Organization: National Research Council, Canada Lines: 122 Message-ID: <3mjnkl$43t@nrcnet0.nrc.ca> NNTP-Posting-Host: ksl0j.ai.iit.nrc.ca Call for Papers EVOLUTIONARY COMPUTATION Special Issue on EVOLUTION, LEARNING, AND INSTINCT: 100 YEARS OF THE BALDWIN EFFECT In 1896, James Mark Baldwin proposed that individual learning can explain evolutionary phenomena that appear to require Lamarckian inheritance of acquired characteristics. The ability of individuals to learn can guide the evolutionary process. In effect, learning smoothes the fitness landscape, thus facilitating evolution. This first aspect of the Baldwin effect has recently received much attention, especially for its applications to computational problem solving. In evolutionary algorithms, local search is analogous to individual learning. Improvements found via local search change the fitness of an individual without changing the actual genotype. Baldwin further proposed that abilities that initially require learning are eventually replaced by the evolution of genetically determined systems that do not require learning. Thus learned behaviours may become instinctive behaviours in subsequent generations, without appealing to Lamarckian inheritance. This aspect of the Baldwin effect deserves more attention. Recent work suggests that intuitive abilities in human language, physics, biology, and arithmetic may be largely instinctive. The Baldwin effect can help us understand the relationship between learning and instinct. Furthermore, increased understanding of this second aspect of the Baldwin effect may enable us to improve the performance of computational problem solving by hybrids of genetic algorithms and local search algorithms. A special issue of Evolutionary Computation is planned for 1996, the 100th anniversary of Baldwin's paper. Evolutionary Computation provides an international forum for facilitating and enhancing the exchange of information among researchers involved in both the theoretical and practical aspects of computational systems of an evolutionary nature. Papers are solicited that address both theoretical and computational work related to evolution, learning, instinct and the Baldwin Effect. Examples of topics of interest include: * When is learning advantageous? Learning can facilitate evolution by allowing individuals to more quickly adapt to fitness landscapes that would otherwise be difficult to exploit; however, the ability to learn weakens the selective forces acting on an individual, which can slow evolutionary change. * When is instinctive behaviour advantageous? Instincts can be fast and dependable in a static environment, although they may not be able to cope with radical environmental change. Thus the trade off between instinctual and learned responses may have implications for search and learning in dynamic computational environments. * From a design perspective, what parts of an individual's cognitive machinery should be modifiable by experience (local search) and what parts should be determined by evolution (genetic search)? For example, in a typical hybrid of a genetic algorithm and a neural network, the genetic algorithm determines the network architecture and back propagation determines the network weights. Is there a Baldwinian justification for this division of labour? * How does learned behaviour become instinctive? It seems plausible that, for some learned behaviours, there is no evolutionary path that leads to an instinctive replacement for the behaviour. For computational problem solving with hybrid genetic algorithms, what techniques can we use to encourage learned behaviours to evolve into instinctive behaviours? Further Information For more information, see "http://ai.iit.nrc.ca/baldwin/cfp.html" on the World Wide Web or send a message to the contact address listed below. Instructions for Submitting Papers Papers should describe mature work that is original in nature and has not been published elsewhere. Manuscripts should be approximately 8,000 to 12,000 words in length and formatted for 8 1/2 x 11-inch paper, single-sided and double-spaced. The first page should include the title, abstract, key words, and author information (name, affiliation, mailing address, telephone number, and e-mail address). The text of the paper should begin on the second page and continue on consecutively numbered pages. For more information on the format, consult the inside back cover of a recent issue of Evolutionary Computation. Send five hard copies (not faxes) to the contact address listed below. Electronic submissions in PostScript are also acceptable. Important Dates Manuscripts due: February 1, 1996 Acceptance notification: May 1, 1996 Final manuscript due: August 1, 1996 Planned Publication date of issue: December 1996 Guest Editors Peter D. Turney, National Research Council, Canada Darrell Whitley, Colorado State University, USA Russell W. Anderson, University of California, USA Contact Address Dr. Peter Turney Knowledge Systems Laboratory Institute for Information Technology National Research Council Canada Ottawa, Ontario, Canada K1A 0R6 (613) 993-8564 (office) (613) 952-7151 (fax) peter@ai.iit.nrc.ca From owner-population-bio@net.bio.net Wed Apr 12 23:00:00 1995 Path: biosci!CR-AM.RNP.BR!astrid From: astrid@CR-AM.RNP.BR Newsgroups: bionet.population-bio Subject: Genera Salix Date: 13 Apr 1995 13:11:03 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 14 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504132010.AA08767@cr-am.rnp.br> NNTP-Posting-Host: net.bio.net Dear Colleagues, My name is Astrid and I am a Master's Degree student at the National Amazonian Research Institute ( Insituto Nacional de Pesquisas da Amazonia ). Would like to know if anyone out there has an interest in the genera Salix of the family Salicaceae...especially aspects of population structure and ecology. My work concerns Salix humboldtiana in floodplains ( varzea in Portuguese ) of the central Amazon area. You can answer in either English or Portuguese if you want. Thanks. From owner-population-bio@net.bio.net Thu Apr 13 23:00:00 1995 Path: biosci!daresbury!trane.uninett.no!Norway.EU.net!EU.net!howland.reston.ans.net!vixen.cso.uiuc.edu!catalpa.inhs.uiuc.edu!user From: dyanega@denr1.igis.uiuc.edu (Doug Yanega) Newsgroups: bionet.population-bio Subject: sex allocation in hermaphrodites Date: 14 Apr 1995 16:11:13 GMT Organization: Illinois Natural History Survey Lines: 16 Message-ID: NNTP-Posting-Host: catalpa.inhs.uiuc.edu I'm not having much luck finding theoretical coverage of the question of the evolution of sex allocation in hermaphrodites. Am I correct in assuming that no one has ever demonstrated anything other than the fundamental Fisherian 1/1 investment ratio in male vs female gametic functions (without some violation of the assumption of equal return on investment; i.e., local mate competition, size-based fecundity effects, etc.)? I'm supposing I would've heard of it if there was ever anything found which was a clear exception to Fisherian logic...and that basic Fisherian logic would predict a 1/1 ratio in hermaphrodites, since they're still diploids. Correct? -- Doug Yanega Illinois Natural History Survey, Center for Biodiversity 607 E. Peabody Dr. Champaign, IL 61820 USA "There are some enterprises in which a careful disorderliness is the true method" - Herman Melville, Moby Dick From owner-population-bio@net.bio.net Thu Apr 13 23:00:00 1995 Path: biosci!daresbury!trane.uninett.no!Norway.EU.net!EU.net!Germany.EU.net!howland.reston.ans.net!vixen.cso.uiuc.edu!catalpa.inhs.uiuc.edu!user From: dyanega@denr1.igis.uiuc.edu (Doug Yanega) Newsgroups: bionet.population-bio Subject: fitness and generation time variation Date: 14 Apr 1995 16:09:03 GMT Organization: Illinois Natural History Survey Lines: 59 Message-ID: NNTP-Posting-Host: catalpa.inhs.uiuc.edu Hi. Apologies for the inevitable cross-postings. I've come up against something which has me quite confused, and I was hoping some folks here might help me clear this hurdle (and it might make an interesting discussion). I'm working with organisms that exhibit mixed voltinism strategies (anywhere from 1-3 broods per year, varying *within* a population), and - intuitively - one would think that individuals producing three broods in a season would (by virtue of the large number of descendants) have a higher fitness than those producing only one. However, calculations of fitness compare the number of gene copies left by one strategy versus the other, and in this case (at least theoretically) they are the same (2 offspring versus 8 great-grandoffspring). Same number of gene copies, but divvied up among different numbers of descendants, and fitness ignores the latter. In discussions I've had it's been pointed out that - theoretically - if the population size is infinite and stable, a hypothetical allele for faster generation time will not increase in frequency because the odds of any given individual carrying it are decreasing at the same rate at which the number of potential carriers increases (it would spread, however, if the population were growing - but "one can never assume this in a general evolutionary model!" - and it would LOSE if the population were shrinking). To me, this is a puzzling thing, because when I've asked it as a question at an absurd extreme: "Which is better: 2 descendants at time X, each with half your genes, or 2000 descendants each with 1/500th??" it inevitably gets the answer "2000", though theoretically they prove to be identical in fitness. Furthermore, the conclusion one is led to above is that selection can't operate to increase or decrease generation time, which is patently absurd. I'm assuming I must be missing something big. Can *anyone* either confirm or deny that there are no adjustments to fitness calculations resulting from variation in generation time, and in either case, how DOES selection affect it? I would like very much to be able to calculate selective advantages/disadvantages to the different strategies in my populations (to figure out the expected frequencies of the different strategies), but theory seems to have me in a bind. A related question that comes to my mind is the conceptual distinction between stating that "Among these 8 great-grandoffspring, only 1 is expected to carry allele X" as opposed to "Each of these 8 should have 1/8th of their genes inherited from their great-grandmother"; the reason is that when I've discussed whether relaxing the "zero-mortality" assumption would make having more descendants a better strategy, the opinion has been "It's irrelevant, since only 1 descendant on average will carry the allele in question no matter how many descendants there are, the odds are always the same for either strategy as to whether that 1 carrier will be affected by a random mortality event". But if you look at my "extreme case" above, and assume a 50% mortality event, the lineage with only 2 descendants is very likely to get wiped out, just by chance, while the one with 2000 will certainly survive. Is this NOT a real possibility? My point being, if you focus only on that allele, it really DOES appear to be irrelevant, but demographically, it's an "all your eggs in one basket" sort of thing. There MUST be a way to quantify the numerical advantage conferred, both in this extreme case, and in cases all the way down to 2 offspring vs. 4 grandoffspring. I feel that there *has* to be some advantage. So, any takers?? Thanks, -- Doug Yanega Illinois Natural History Survey, Center for Biodiversity 607 E. Peabody Dr. Champaign, IL 61820 USA "There are some enterprises in which a careful disorderliness is the true method" - Herman Melville, Moby Dick From owner-population-bio@net.bio.net Thu Apr 13 23:00:00 1995 Path: biosci!COMP.UARK.EDU!wetges From: wetges@COMP.UARK.EDU (William J. Etges) Newsgroups: bionet.population-bio Subject: Re: sex allocation in hermaphrodites Date: 14 Apr 1995 09:54:08 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 41 Sender: daemon@net.bio.net Distribution: world Message-ID: <199504141653.LAA28769@comp.uark.edu> NNTP-Posting-Host: net.bio.net At 4:11 PM 14/4/95 +0000, Doug Yanega wrote: >I'm not having much luck finding theoretical coverage of the question of >the evolution of sex allocation in hermaphrodites. Am I correct in >assuming that no one has ever demonstrated anything other than the >fundamental Fisherian 1/1 investment ratio in male vs female gametic >functions (without some violation of the assumption of equal return on >investment; i.e., local mate competition, size-based fecundity effects, >etc.)? I'm supposing I would've heard of it if there was ever anything >found which was a clear exception to Fisherian logic...and that basic >Fisherian logic would predict a 1/1 ratio in hermaphrodites, since they're >still diploids. Correct? >-- >Doug Yanega >Illinois Natural History Survey, Center for Biodiversity >607 E. Peabody Dr. Champaign, IL 61820 USA >"There are some enterprises in which a careful disorderliness is > the true method" - Herman Melville, Moby Dick Doug, Check out "The Theory of Sex Allocation" by E. L. Charnov, 1982, Princeton University Press. Its a good place to start. Bill ------------------------------------------------------------------------- William J. Etges "I wish the Bald Eagle Department of Biol. Sciences had not been chosen University of Arkansas as the Representative Fayetteville, AR 72701 USA of our country! The wetges@comp.uark.edu Turkey is a much more voice: (501) 575-6358 respectable Bird, FAX (501) 575-4010 and withal a true native of America." -Benjamin Franklin, from a letter to his daughter. ------------------------------------------------------------------------- From owner-population-bio@net.bio.net Thu Apr 13 23:00:00 1995 Path: biosci!CORNELL.EDU!lyy1 From: lyy1@CORNELL.EDU (Lev Yampolsky) Newsgroups: bionet.population-bio Subject: Re: sex allocation in hermaphrodites Date: 14 Apr 1995 10:21:15 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 19 Sender: daemon@net.bio.net Distribution: world Message-ID: <199504141720.NAA21019@postoffice3.mail.cornell.edu> NNTP-Posting-Host: net.bio.net Doug: >I'm not having much luck finding theoretical coverage of the question of >the evolution of sex allocation in hermaphrodites. Am I correct in >assuming that no one has ever demonstrated anything other than the >fundamental Fisherian 1/1 investment ratio in male vs female gametic >functions Doug, Check out my note in Evolution a couple of years ago (v.46: 833-837). It's about cyclic parthenogen Daphnia, but effectively, a parthenogenetic clone (single genotype) able to produce both males and sexual females is an equivalent of a hermaphrodite. Maybe this helps. Regards, Lev Yampolsky From owner-population-bio@net.bio.net Sat Apr 15 23:00:00 1995 Path: biosci!agate!howland.reston.ans.net!news.sprintlink.net!uunet!in1.uu.net!newsflash.concordia.ca!news.mcgill.ca!pigeon.biol.mcgill.ca!user From: thomas@moulon.inra.fr (Thomas Bataillon) Newsgroups: bionet.population-bio Subject: Re: sex allocation in hermaphrodites Date: 16 Apr 1995 15:34:06 GMT Organization: Mc Gill university, Biology Department Lines: 23 Message-ID: References: NNTP-Posting-Host: pigeon.biol.mcgill.ca In article , dyanega@denr1.igis.uiuc.edu (Doug Yanega) wrote: @ I'm not having much luck finding theoretical coverage of the question of @ the evolution of sex allocation in hermaphrodites. (... rest of the message removed...) @ Doug Yanega @ Illinois Natural History Survey, Center for Biodiversity I would suggest you the following paper: Martin T. Morgan. 1994. Models of sexual selection in hermaphrodites, especially plants. American Naturalist. Vol 144, supplement, pp. S100-S125. Regards, -- Thomas Bataillon Departement of Biology McGill University 1205, av. Docteur Penfield Montreal, PQ, Canada H3A 1B1 internet: thomas@moulon.inra.fr (mail will be forwarded) From owner-population-bio@net.bio.net Sun Apr 16 23:00:00 1995 Path: biosci!bloom-beacon.mit.edu!panix!zip.eecs.umich.edu!newsxfer.itd.umich.edu!gatech!howland.reston.ans.net!news.cac.psu.edu!news.tc.cornell.edu!travelers.mail.cornell.edu!newsstand.cit.cornell.edu!NewsWatcher!user From: lyy1@cornell.edu (Lev Yampolsky) Newsgroups: bionet.population-bio,bionet.drosophila Subject: Anyone needs X-linked lethals? Followup-To: bionet.population-bio,bionet.drosophila Date: Mon, 17 Apr 1995 15:31:45 -0400 Organization: Cornell University Lines: 12 Sender: lyy1@cornell.edu (Verified) Distribution: world Message-ID: NNTP-Posting-Host: 132 Xref: biosci bionet.population-bio:1364 bionet.drosophila:1013 Hi everyone, The subject sais it all - we have 15 brand new lethal mutations in D.melanogaster balancer X chromosomes which we do not need anymore and are going to dump. If anyone needs this valuable commodity, we are ready to share. -- Alex Kondrashov and Lev Yampolsky Section of Ecology and Systematics Cornell University From owner-population-bio@net.bio.net Sun Apr 16 23:00:00 1995 Path: biosci!rutgers!gatech!howland.reston.ans.net!news.cac.psu.edu!news.tc.cornell.edu!travelers.mail.cornell.edu!newsstand.cit.cornell.edu!NewsWatcher!user From: lyy1@cornell.edu (Lev Yampolsky) Newsgroups: bionet.population-bio,bionet.drosophila Subject: Re: Anyone needs X-linked lethals? Followup-To: bionet.population-bio,bionet.drosophila Date: Mon, 17 Apr 1995 16:04:43 -0400 Organization: Cornell University Lines: 12 Sender: lyy1@cornell.edu (Verified) Distribution: world Message-ID: References: NNTP-Posting-Host: 132 Xref: biosci bionet.population-bio:1365 bionet.drosophila:1014 In article , lyy1@cornell.edu (Lev Yampolsky) wrote: >... we have 15 brand new lethal mutations in > D.melanogaster balancer X chromosomes... Ooops... The mutations are in the wild chromosome kept against the balancer. -- Lev Yampolsky From owner-population-bio@net.bio.net Mon Apr 17 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Biology's focus on human selection Date: 17 Apr 1995 18:31:14 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 75 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504180136.AA00914@tempest.adsnet.net.adsnet.net> NNTP-Posting-Host: net.bio.net Summary: The human brain and society's information systems are replacing DNA and natural events as the engine of genetic trait selection, either for species enhancement or decline. Biology cannot "endorse" these systems because their workings are not biological. Biology can, however, observe and consider long-run effects of these systems while denying "species improvement" claims by unproven selection systems. ****************** * Proposed equation: Viability of future human genepool = -A- (times) reproduction ****************** where -A- is "accuracy of selection process" -- of human gene lines, gene pools, family lines (or even ideologies, because these heavily influence trait selection) ****************** * Proposed corollary: These ideas will seem circular at first, but ****************** society practices artificial selection based on _perceived_ success; in nature, _perceived_ success is the same as actual success. Can we prove religions, national customs or money systems select for future species viability? The test, not necessarily circular, will be whether in a long run the species will be enhanced. If the species declines in the long run, those systems have selected for failure. ****************** * Proposed caveat: Ideology still dominates all discussion of human selection. ****************** Biology cannot say an individual's fate was selected accurately. Biology cannot endorse the validity of religion and currency systems as selecting for human genetic viability because: 1) The human genome contains as yet unknown variables influencing "success." ( For example, maybe it's that ratio of spleen to temporal lobe that fosters _one kind of success_ in one era of human artificial selection, only to fail in the next era when a civilization collapses, crushing a promising genetic combination.) 2) Cause-effect relationships between specific genetic traits and "success" have only been shown to a very limited degree in human society. 3) The time line in human society is too short. A bio-definition of human success would evaluate whether the system is selecting for its own failure. (ie. Gregor Mendel probably had no children, so was he a biological success? Was society's system selecting for success? How many people have missed their mark because their appearance caused them one obstacle too many in a shallow society? We are fortunate to have the legacy of persons like Amadeo Avogadro (inventor of the "mole" as a unit in chemistry and said to have a face like a mole). Biology cannot in its present condition make adequate scientific endorsements of "selection" in human society. Noone else can yet either, and biology might be closest. However, there is a tendency to rush to judgement in fields other than our own. Mike Pearson e5079021@tempest.adsnet.net The deepest definition of Youth is Life as yet untouched by tragedy. -- George Santayana From owner-population-bio@net.bio.net Mon Apr 17 23:00:00 1995 Path: biosci!rutgers!gatech!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!newsspool.doit.wisc.edu!decwrl!tribune.usask.ca!canopus.cc.umanitoba.ca!newsflash.concordia.ca!news.mcgill.ca!VM1.MCGILL.CA From: "LYVER,ANDRE,MR" Newsgroups: bionet.population-bio Subject: population size Date: 18 APR 95 10:21:42 EST Organization: McGill University Lines: 9 Sender: usenet@MUSICB.MCGILL.CA Message-ID: <18APR95.11190600.0313@VM1.MCGILL.CA> NNTP-Posting-Host: vm1.mcgill.ca I just recently encountered this question in one of my classes:" The current population of the earth is approximately 5.6 billion people. One person says there are too many people in the world. Another disagrees. What criteria are used to decide whether the human population is too large?" I would appreciate any suggestions/replies/comments. Andre Lyver xnlc@musicb.mcgill.ca From owner-population-bio@net.bio.net Mon Apr 17 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Re: Biology's focus on human selection Date: 17 Apr 1995 21:57:30 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 19 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504180457.AA02760@tempest.adsnet.net.adsnet.net> NNTP-Posting-Host: net.bio.net -and- -A- = (ideology minus errors) + future accurate adjustments So, please tell if the previous article was wrong, and how, or how to improve it for public policy purposes. What is biology's position? Recapping----------(as in previous article)------- * Proposed equation: Viability of future human genepool = -A- (times) reproduction where -A- is "accuracy of selection process" -- of human gene lines, gene pools, family lines (or even ideologies, because these heavily influence trait selection) ***(as elaborated)*** From owner-population-bio@net.bio.net Mon Apr 17 23:00:00 1995 Newsgroups: bionet.population-bio Path: biosci!rutgers!gatech!howland.reston.ans.net!news.sprintlink.net!sunserver.insinc.net!news.Direct.CA!scipio.cyberstore.ca!vanbc.wimsey.com!news.mindlink.net!news.bc.net!rover.ucs.ualberta.ca!tribune.usask.ca!canopus.cc.umanitoba.ca!newsflash.concordia.ca!news.mcgill.ca!clouso.crim.ca!uqac.uquebec.ca!SOREP.uqac.uquebec.ca!EVELYNE From: evelyne@SOREP.uqac.uquebec.ca Subject: Re: fitness and generation time variation Message-ID: Sender: usenet@uqac.uquebec.ca Nntp-Posting-Host: sorep Reply-To: evelyne@SOREP.uqac.uquebec.ca Organization: SOREP, Chicoutimi, Quebec, Canada References: Date: Mon, 17 Apr 1995 21:28:32 GMT Lines: 72 In article , dyanega@denr1.igis.uiuc.edu (Doug Yanega) writes: >Hi. Apologies for the inevitable cross-postings. I've come up against >something which has me quite confused, and I was hoping some folks here >might help me clear this hurdle (and it might make an interesting >discussion). I'm working with organisms that exhibit mixed voltinism >strategies (anywhere from 1-3 broods per year, varying *within* a >population), and - intuitively - one would think that individuals >producing three broods in a season would (by virtue of the large number of >descendants) have a higher fitness than those producing only one. However, >calculations of fitness compare the number of gene copies left by one >strategy versus the other, and in this case (at least theoretically) they >are the same (2 offspring versus 8 great-grandoffspring). Same number of >gene copies, but divvied up among different numbers of descendants, and >fitness ignores the latter. In discussions I've had it's been pointed out >that - theoretically - if the population size is infinite and stable, a >hypothetical allele for faster generation time will not increase in >frequency because the odds of any given individual carrying it are >decreasing at the same rate at which the number of potential carriers >increases (it would spread, however, if the population were growing - but >"one can never assume this in a general evolutionary model!" - and it >would LOSE if the population were shrinking). > To me, this is a puzzling thing, because when I've asked it as a >question at an absurd extreme: "Which is better: 2 descendants at time X, >each with half your genes, or 2000 descendants each with 1/500th??" it >inevitably gets the answer "2000", though theoretically they prove to be >identical in fitness. Furthermore, the conclusion one is led to above is >that selection can't operate to increase or decrease generation time, >which is patently absurd. I'm assuming I must be missing something big. >Can *anyone* either confirm or deny that there are no adjustments to >fitness calculations resulting from variation in generation time, and in >either case, how DOES selection affect it? I would like very much to be >able to calculate selective advantages/disadvantages to the different >strategies in my populations (to figure out the expected frequencies of >the different strategies), but theory seems to have me in a bind. > A related question that comes to my mind is the conceptual distinction >between stating that "Among these 8 great-grandoffspring, only 1 is >expected to carry allele X" as opposed to "Each of these 8 should have >1/8th of their genes inherited from their great-grandmother"; the reason >is that when I've discussed whether relaxing the "zero-mortality" >assumption would make having more descendants a better strategy, the >opinion has been "It's irrelevant, since only 1 descendant on average >will carry the allele in question no matter how many descendants there >are, the odds are always the same for either strategy as to whether that 1 >carrier will be affected by a random mortality event". But if you look at >my "extreme case" above, and assume a 50% mortality event, the lineage >with only 2 descendants is very likely to get wiped out, just by chance, >while the one with 2000 will certainly survive. Is this NOT a real >possibility? My point being, if you focus only on that allele, it really >DOES appear to be irrelevant, but demographically, it's an "all your eggs >in one basket" sort of thing. There MUST be a way to quantify the >numerical advantage conferred, both in this extreme case, and in cases all >the way down to 2 offspring vs. 4 grandoffspring. I feel that there *has* >to be some advantage. So, any takers?? >Thanks, >-- >Doug Yanega >Illinois Natural History Survey, Center for Biodiversity >607 E. Peabody Dr. Champaign, IL 61820 USA >"There are some enterprises in which a careful disorderliness is > the true method" - Herman Melville, Moby Dick The main difference between these strategies is not the mean, it is the variance of this process. Or, the probability of losing a gene. So for a strategy with same mean, you should say that the best is the one with the smallest probability of losing a gene. Evelyne Heyer eheyer@uqac.uquebec.ca From owner-population-bio@net.bio.net Mon Apr 17 23:00:00 1995 Path: biosci!TEMPEST.ADSNET.NET!e5079021 From: e5079021@TEMPEST.ADSNET.NET (Mike Pearson) Newsgroups: bionet.population-bio Subject: Re: population size Date: 18 Apr 1995 10:03:34 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 37 Sender: daemon@net.bio.net Distribution: world Message-ID: <9504181708.AA06369@tempest.adsnet.net.adsnet.net> NNTP-Posting-Host: net.bio.net >I just recently encountered this question in one of my classes:" The >current population of the earth is approximately 5.6 billion people. >One person says there are too many people in the world. Another >disagrees. What criteria are used to decide whether the human population >is too large?" >I would appreciate any suggestions/replies/comments. >Andre Lyver >xnlc@musicb.mcgill.ca > > Here's part of the answer, from _Living Within Limits_ by Garrett Hardin and _The Population Explosion_ by Paul and Ann Ehrlich 1) Two billion-plus increase since 1970 shows there is great momentum and it's taking a long time to apply the brakes. 2) Read the environment. The carrying capacity is being exceeded over vast areas of Earth. The burden of proof is on the side of the argument which violates common sense. ("Carrying capacity" is defined as a stable number of animals that can besupported year after year without damaging the environment. Whenever a population grows beyond the carrying capacity, the environment is rapidly degraded; as a result, carrying capacity is reduced in subsequent years.) 3) Cultural carrying capacity is being exceeded. The quality of life and the quantity of it are inversely related. 4) Perhaps the world is not over populated, but many _parts of it are, as indicated by reading the environment. A general rule is 'Calling it a world problem is useful only if there is a plausible worldwide solution.' But the problem is created by local action and must be solved by local action. 5) Millions who live in poverty are kept so by local overpopulation. There is widespread starvation, disease and tragic drowning deaths by the thousands of those forced to live on flood plains. 6) The world probably could not support the present population at the developed world's level of material wealth without severe, widespread destruction of the planetary life support system. From owner-population-bio@net.bio.net Wed Apr 19 23:00:00 1995 Path: biosci!rutgers!uwm.edu!cs.utexas.edu!swrinde!emory!news.cc.emory.edu!learnlink.emory.edu!user From: Paula_Martin@learnlink.emory.edu (Paula Martin) Newsgroups: bionet.population-bio Subject: Re(2): population size Date: Thu, 20 Apr 95 19:07:42 -0500 Organization: Project LearnLink - Emory University Lines: 26 Message-ID: <1034979.ensmtp@learnlink.emory.edu> NNTP-Posting-Host: postal_union2.learnlink.emory.edu X-Newsreader: ExpressNet/SMTP v1.1.4 Nice answer to the "is 5.6 billion too many people? and how to we decide?" question. Here's another tidbit: Pimentel notes that with the currently, with all the land resources of the planet, there is not enough arable land to feed the population (at that time: 5 billion) a high-protein, high-calorie, U.S.-type diet. And this assumes that ALL the world's arable land was switched to human food production. Source: Pimentel, D., 1989. Ecological systems, natural resources and food supplies, IN: (Pimentel & Hall, ed.) Food and Natural Resources. Academic Press, San Diego. -- /========/ LearnLink: Expanding Educational Horizons !! !! !! Internet/Telnet: bbs.learnlink.emory.edu !! !! !! For information, mail Info@learnlink.emory.edu /========/ "Minds are like parachutes, they must be open to function." From owner-population-bio@net.bio.net Thu Apr 20 23:00:00 1995 Path: biosci!bcm!cs.utexas.edu!swrinde!howland.reston.ans.net!vixen.cso.uiuc.edu!catalpa.inhs.uiuc.edu!user From: dyanega@denr1.igis.uiuc.edu (Doug Yanega) Newsgroups: bionet.population-bio Subject: Re: fitness and generation time variation Date: 21 Apr 1995 07:03:41 GMT Organization: Illinois Natural History Survey Lines: 43 Message-ID: References: <3n6vfq$p7s@mark.ucdavis.edu> NNTP-Posting-Host: catalpa.inhs.uiuc.edu In article <3n6vfq$p7s@mark.ucdavis.edu>, dave@dmitri.ucdavis.edu wrote: {much deleted - I leave town in a few hours and can't fully go into this] > Wait I think this is just confused. Suppose we consider the descendants of two > individuals. One has 2 descendents each with exactly 1/2 the original genome. Suppose > 1/2 the population dies. Then the expected number of gene copies of the first > individual is 1/2 the orginal genome, the variance is 0+(1/4)/2 = 1/8, the probability of extinction > is 1/4. For the case of an individual with 3 generation, 8 descendents with > on average 1/8 the genome, the expected number of copies is 1/2, the > variance is (2*1/4) + (1/4)/8 = 17/32, and the probability of extinction is > hard to calculate (it's a function of the number of chromosome and the recombination > rate). If we assume for simplicity there > is one chromosome and no recombination, then the probability of extinction is not too > hard to work out, but I've messed it up twice already (on my little scrap of paper), > so unless you're really curious I won't bother. Suffice it to say that it is greater > than 1/4, which should be obvious from the fact that the variance in the number of copies > is greater than the mean. Bingo. That was precisely the conclusion I was groping for - it is possible to have an identical *arithmetic* mean fitness, but a different *geometric* mean fitness, and this has indeed been cited as a significant evolutionary phenomenon. It is *independent* of environmental variation, and independent of whether or not the population is growing. All other things being equal, it *is* better to have your genome distributed among *more* descendants. It took me a while, but I found the references for this I needed. All the rest of the post was just leading up to this... Cheers, -- Doug Yanega Illinois Natural History Survey, Center for Biodiversity 607 E. Peabody Dr. Champaign, IL 61820 USA "There are some enterprises in which a careful disorderliness is the true method" - Herman Melville, Moby Dick From owner-population-bio@net.bio.net Thu Apr 20 23:00:00 1995 Path: biosci!rutgers!gatech!swrinde!cs.utexas.edu!news.sprintlink.net!noc.netcom.net!netcom.com!csus.edu!news.ucdavis.edu!dmitri.ucdavis.edu!dave From: dave@news.ucdavis.edu (David Cutler) Newsgroups: bionet.population-bio Subject: Re: fitness and generation time variation Date: 21 Apr 1995 00:50:02 GMT Organization: Center for Population Biology Lines: 155 Message-ID: <3n6vfq$p7s@mark.ucdavis.edu> References: Reply-To: dave@dmitri.ucdavis.edu NNTP-Posting-Host: dmitri.ucdavis.edu X-Newsreader: TIN [version 1.2 PL2] I'm sorry, I've just competely misunderstood what you are talking about. Could you clear this up for me. Doug Yanega (dyanega@denr1.igis.uiuc.edu) wrote: : Hi. Apologies for the inevitable cross-postings. I've come up against : something which has me quite confused, and I was hoping some folks here : might help me clear this hurdle (and it might make an interesting : discussion). I'm working with organisms that exhibit mixed voltinism : strategies (anywhere from 1-3 broods per year, varying *within* a : population), and - intuitively - one would think that individuals : producing three broods in a season would (by virtue of the large number of : descendants) have a higher fitness than those producing only one. However, : calculations of fitness compare the number of gene copies left by one : strategy versus the other, and in this case (at least theoretically) they : are the same (2 offspring versus 8 great-grandoffspring). Same number of Okay, I don't really understand what you are talking about. Is the situation that there is variance in the number of broods a single individual has in a season (i.e. some guys have three batchs of offspring while others only one), or is it that some individuals have a generation time that is 1/3 third the length of others (i.e. some individuals are born, reproduce and die in 1/3 the time it takes others)? If it is the first case, then clearly if the expected number of surviving offspring were the same for each brood, then the number of descendents produced by an individual with 3 broods per season is 3 times as high as those for one brood. So theoretically, more broods ought to be better. So, is your point that when you go out and measure these guys that individuals with 3 broods have no more offspring in the next generation then those with one brood? Or do you observe no more offspring in the third generation hence? I'm not sure what you are observing. Moreover, is there any reason to suspect number of broods per season is genetically controlled? A priori one might imagine that the number of broods per season is essentially environmentally controlled. The idea is the individuals who eat well prior to breeding season get lots of broods, and those that didn't don't. And if conditioning was random with respect to genotype, if you looked at a generation far enough down the road, the expected number of offspring n generations from now would essentially be independent of the number of offspring produced in this generation. : gene copies, but divvied up among different numbers of descendants, and : fitness ignores the latter. In discussions I've had it's been pointed out : that - theoretically - if the population size is infinite and stable, a : hypothetical allele for faster generation time will not increase in : frequency because the odds of any given individual carrying it are : decreasing at the same rate at which the number of potential carriers : increases (it would spread, however, if the population were growing - but : "one can never assume this in a general evolutionary model!" - and it : would LOSE if the population were shrinking). Judging from this paragraph I think I should take it that some individuals have a generation time that is 1/3 as long as others. If this is the case, I'm not sure I understand your intuition as to why a shorter generation time ought to be favored. To make this simple, consider an asexual population. Suppose that generations are discrete, and that the expected number of offspring an individual gets in the next generation is 1. Now a mutation that caused an individual to have a generation time 1/3 as long as the rest, certainly wouldn't be favored. The expected number of copies of this gene at some time t in the future is still one. The probability of that gene fixing in the population some time in the future is 1/n (n is population size), and the probability of eventual loss of the gene is 1-1/n, all of which is the same as any other neutral mutation. The only difference is that the mean time to loss or fixation will be 1/3 as long for your mutant. : To me, this is a puzzling thing, because when I've asked it as a : question at an absurd extreme: "Which is better: 2 descendants at time X, : each with half your genes, or 2000 descendants each with 1/500th??" it : inevitably gets the answer "2000", though theoretically they prove to be : identical in fitness. Furthermore, the conclusion one is led to above is : that selection can't operate to increase or decrease generation time, : which is patently absurd. I'm assuming I must be missing something big. First, clearly getting 2000 descendants with 1/500th your genome is better than 2 with 1/2 (2000*1/500 = 4, 2*1/2 = 1). So I'll assume you meant something like 500 individuals with 1/500th your genome. Selection obviously can act to change generation time, but as you discovered, it won't do this in a constant size population. If, say the expected number of offspring produce in our hypothetical population were 2, instead of 1 each generation, then the expected number of offspring produced by our mutant at after t genertions in our base population is 2^(3*t), whereis it is merely 2^(t) for the rest of the population. For example, suppose t=10, then the rest of the population has 1,024 copies of its orgininal genome, but our mutant has 1,073,741,824 copies. If our initial population size were about 1 million, then our final population size will be about 2 billion. The frequency of our mutant started out around 1 in a million, but after 10 generations is about 1/2. A similar scenario occurs if the average number of offspring produced is less than 1, only now the mutant is selected against. The overall idea is that if r is the expected number of offspring produced per generation per individual and t1 < t2, r^(t1) < r^(t2) iff r>1, r^(t1) > r^(t2) iff r<1, r^(t1) = r^(t2) if r=1. Which tells us that shrinking generation time is favored if the population is growing, is disfavored if the population is shrinking, and nothing matters in a constant population. : Can *anyone* either confirm or deny that there are no adjustments to : fitness calculations resulting from variation in generation time, and in : either case, how DOES selection affect it? I would like very much to be : able to calculate selective advantages/disadvantages to the different : strategies in my populations (to figure out the expected frequencies of : the different strategies), but theory seems to have me in a bind. So to say something about the fitness of the different generation time strategies you need to know something about the fluctation in population sizes. Is the population on average growing?shrinking? remaining the same? You'll need a lot of data of population size over a long period time to say any meaningful. : A related question that comes to my mind is the conceptual distinction : between stating that "Among these 8 great-grandoffspring, only 1 is : expected to carry allele X" as opposed to "Each of these 8 should have : 1/8th of their genes inherited from their great-grandmother"; the reason : is that when I've discussed whether relaxing the "zero-mortality" : assumption would make having more descendants a better strategy, the : opinion has been "It's irrelevant, since only 1 descendant on average : will carry the allele in question no matter how many descendants there : are, the odds are always the same for either strategy as to whether that 1 : carrier will be affected by a random mortality event". But if you look at : my "extreme case" above, and assume a 50% mortality event, the lineage : with only 2 descendants is very likely to get wiped out, just by chance, : while the one with 2000 will certainly survive. Is this NOT a real : possibility? My point being, if you focus only on that allele, it really : DOES appear to be irrelevant, but demographically, it's an "all your eggs : in one basket" sort of thing. There MUST be a way to quantify the : numerical advantage conferred, both in this extreme case, and in cases all : the way down to 2 offspring vs. 4 grandoffspring. I feel that there *has* : to be some advantage. So, any takers?? Wait I think this is just confused. Suppose we consider the descendants of two individuals. One has 2 descendents each with exactly 1/2 the original genome. Suppose 1/2 the population dies. Then the expected number of gene copies of the first individual is 1/2 the orginal genome, the variance is 0+(1/4)/2 = 1/8, the probability of extinction is 1/4. For the case of an individual with 3 generation, 8 descendents with on average 1/8 the genome, the expected number of copies is 1/2, the variance is (2*1/4) + (1/4)/8 = 17/32, and the probability of extinction is hard to calculate (it's a function of the number of chromosome and the recombination rate). If we assume for simplicity there is one chromosome and no recombination, then the probability of extinction is not too hard to work out, but I've messed it up twice already (on my little scrap of paper), so unless you're really curious I won't bother. Suffice it to say that it is greater than 1/4, which should be obvious from the fact that the variance in the number of copies is greater than the mean. hope this cleared some stuff up, dave cutler dave@dmitri.ucdavis.edu : Thanks, : -- : Doug Yanega : Illinois Natural History Survey, Center for Biodiversity : 607 E. Peabody Dr. Champaign, IL 61820 USA : "There are some enterprises in which a careful disorderliness is : the true method" - Herman Melville, Moby Dick From owner-population-bio@net.bio.net Fri Apr 21 23:00:00 1995 Path: biosci!DEAKIN.EDU.AU!ggoodwin From: ggoodwin@DEAKIN.EDU.AU (Glenn Goodwin) Newsgroups: bionet.population-bio Subject: Help Finding Resources for Population Explosion Date: 21 Apr 1995 23:51:44 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 11 Sender: daemon@net.bio.net Distribution: world Message-ID: NNTP-Posting-Host: net.bio.net Hi, I'm currently studying at Deakin Uni (Australia). I have an essay on the Population Explosion and cant seem to find any up to date resources on population sizes. If anyone knows an easy place on the Net or libraries I would be appreciative. When reading a book I found the term fertility rate. Could someone please tell me what this means.