What selfish genes prefer...

Ben Jones jonesbb at BELOIT.EDU
Mon Feb 15 21:44:27 EST 1993


Barry Hall (responding to Cary O'Donnell) writes:

>The concept of selfish genes applies to sequences
>that over replicate in the genome, and confer no obvious benefit upon the
>host.  

It is understandable that you would think this, because it seems so
unreasonable that a real scientist would use language like that about
normal evolution.  Unfortunately Richard Dawkins was NOT referring to gene
over-replication in his book,  "The Selfish Gene".  He was talking about
all genes, and attempting to disprove the idea of "altruistic" behavior, or
behavior that benefits the group or the species rather than the individual.
 Allow me to quote from the New Edition, chapter 1, page 3:

"I shall argue that a predominant quality to be expected in a successful
gene is ruthless selfishness.  This gene selfishness will usually give rise
to selfishness in individual behavior.  However, as we shall see, there are
special circumstances in which a gene can achieve its own selfish goals
best by fostering a limited form of altruism at the level of individual
animals."

In his zeal to trash group selection, Dawkins trashed the language of
evolution instead.  (And produced a book which is eminently readable for
beginners in evolution, and explains simply and concisely many of the most
complicated concepts in evolutionary theory.  The notable exception is
group selection, which he does not understand at all.)


>We can observe over-replication as increases in copy number of some
>sequences, but we can not be sure that there is no advantage to the host...
>we can only be sure that we don't know of any such advantage at this time.
>While the concept of selfish genes is important becaue it contradicts what
>was the prevailing view (that all genes must confer some benefit on the
>host or they wouldn't be there), it is intellectually sloppy and the
>antithesis of good science to discuss selfish genes as though their existence
>were undisputed fact.  The existence of selfish genes is a good hypothesis
>and there is considerable evidence that is consistent with that hypothesis.

I believe that what you are referring to as over-replication is also called
meiotic drive, and there are well studied cases of it.  The t-alelle in
mice is one such case and I can probably find a reference for it if anyone
is interested. 


>Period.  To then begin to attribute desires and preferences to such
>hypothesized entities is not only absurd, it is just the sort of sloppy use
>of language that leads many molecular biologists to the couclusion that
>evolutionary biologists are not only a bit daft, but that they can not
>distinguish fact from fancy.

Please don't judge all evolutionary biologists for the sins of a few.  Most
evolutionary scientists use the term to refer to Dawkins' point of view. 
(I don't think it can be called a theory - it has no predictive power.) 
Note that in Cary O'Donnell's post it is used in quotes in both cases:

>>>   "selfish gene" view seems to preclude any argument that would make

>>Ouch!!! You surely don't mean that a "selfish gene", by definition, must


On the other hand, I am often amazed at the number of evolutionary
scientists who think the book "The Selfish Gene" is good science rather
than a well-written tirade against group selection.





Ben Jones                  BioQUEST / Department of Biology
jonesbb at beloit.edu         Beloit College, Beloit, Wisconsin




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