Re. brain sizes: Einstein's and women's

Dave Wilson testaccount2002 at btopenworld.com
Sun Oct 20 18:19:09 EST 2002


Jd wrote:
> 
> Why they keep on insisting that men sprang from mud via apes and
> simultaneously reject the notion that human evolution isn't subject
> to gene dominance rules as are other critters (which would lead
> eventually to a new and improved species) is puzzeling.  To them
> there simply can never be a higher human form other than the one
> which currently occupies the earth.  
> 
> The logical conclusion to that argument is that evolution is static
> when it comes to humans, which means that the argument of "one race,
> forever" contridicts the science of "liberals" themselves.  
> 

I'm a bit unsure what you mean by 'gene dominance rules' - 
dominance/recessiveness is entirely unrelated to how 'desirable' the 
effect of a particular gene is reckoned to be. It's a matter of 
biochemistry, rather than moral judgement. Also, 'improved' only has 
evolutionary meaning in relation to the reproductive environment

Future human evolution is an interesting area for debate. There are 
maybe two different (though overlapping) areas to consider.

First, the slow changes to the balance of various genes in the whole 
species over time. For example, global exposure to infectious diseases 
(which has become more possible in the last few hundred years due to the 
amount of travel of people and goods) may influence the prevalence of 
verious gene variants, particularly in the immune-system areas of the 
genome. Similarly, the supression or eradication of human diseases, 
whether by immunisation or other means may reduce the pressure required 
to maintain the prevalence of a resistance-related gene which has a 
definite negative side (if it were possible to wipe out malaria, there 
could be a selective disadvantage everywhere on the planet to carriers 
of the sickle-cell trait.) Maybe people with a natural resistance to 
pollutants might be at selective advantage.?

Secondly, speciation - primarily the (eventual) appearance of two sets 
of human descendants who have been separated for sufficiently long for 
interbreeding producing fertile offspring to have become biologically 
difficult/impossible. Alternatively, rather than slow drift after a long 
period of mutual separation of two human populations, possibly some kind 
of 'founder event' (mutation or deliberate genetic intervention) might 
cause a subpopulation of humans to arise who are sufficiently 
incompatible with the main human population (but ferile within their own 
group) to enable them to be considered a separate species.

Unfortunately for someone desiring actual speciation, it seems that even 
when human populations have apparently been effectively isolated for 
thousands of years, matings between populations are still successful in 
producing fertile offspring, and the amount of modern travel and 
interbreeding would render slow-drift speciation effectively impossible.

I guess someone could try and *deliberately* set up a separate species, 
but even if it were possible, I suspect that most of the types likely to 
want to do that sort of thing are the kind whose offspring wouldn't be 
any great loss to the mass of humanity.


 > If the ToE is in fact true, a new human species will eventually
 > evolve, which at the onset might appear to "liberals" as beings
 > claiming "super-race" status (which of course couldn't be
 > tolerated).

Barring human genetic intervention, the creation of any new species 
would be so slow and gradual that there wouldn't be any significant 
point at which anyone could claim to be part of the new species. You can 
only really define a species with hindsight.


Dave W.




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