IIRC, that was in the hype phase just after the discovery of the molecular clock in the Y chromosome. Can't find any reference to it now, except an indirect pointer in the Wikipedia article on population bottlenecks, where it is stated that the molecular clocks disproves a bottleneck as tight as the number you mentioned. http://en.wikipedia.org/wiki/Population_bottleneck
When it comes to particular brain skills in humans, I'd say that what we are particularly good at is "jumping to conclusions". :-) I mean, to see patterns in things. As a survival skill it is very good because it enables a much more precise anticipation of events, based on thin experience, than in other species. The brain is a bit hyperactive and may well spot false positives, but it's still a pretty successful trait. As a reproductive skill it's also important, and perhaps more so in today's egalitarian(ish), sexually "almost" unbiased societies (we're far from there, I know, but there's aspiration to get there). But anyway, the time perspective for the evolution of the brain must be at least 60,000 years, and maybe as much as 2 or 2.5 million years. Within those time frames, most of the evolution of the brain must have taken place in analphabetic, hunter-gatherer populations. Thus, if a power-hungry brain was a bad trait then, the lesser brains would have prevailed. AFAIK, there's been some claims that the neanderthals were displaced by H. sapiens precisely because the latter had more creative and inventive brains, but also AFAIK, it's not very well substantiated. All fascinating nonetheless...:-) Jostein 2007/6/13, P. J. Alling <[EMAIL PROTECTED]>: > That's true, but in hard times, (and there have been a lot of hard > times), something as anti survival as a resource hungry giant brain, > that hasn't yet reached real survival value, (and the brain is very > resource hungry), would be very anti-survival. I don't remember exactly > where I've read this but, I seem to recall that at one point the > progenitors of current humanity were down to 8 or so individuals, (based > on some genetic study or other). That is rather extreme speciation > The only other modern species that had such a close call are cheetahs, > at a much later time period. > > AlunFoto wrote: > > Human brain development may well be a runaway evolution process, just > > like the tail feathers of paradise birds, reindeer antlers, etc. etc. > > Any feature that enhance your probability of reproduction can continue > > evolving far beyond mere likelihood of survival. > > > > There's a lot of literature... > > > > Jostein > > > > 2007/6/13, P. J. Alling <[EMAIL PROTECTED]>: > > > >> No you've not paid attention to the literature. A larger brain is > >> helpful up to the point where it stops helping with basic survival. > >> This happens quite a bit smaller than ours. In fact at the size of homo > >> habilis, after that, until the advent of true tool making and real > >> cooperation beyond a hunt it's just dead weight. The brain is ghastly > >> expensive in energy resources for the human body and incremental changes > >> in size from that point don't add to capabilities enough to make up for > >> the costs. The development of a larger than needed brain was not pure > >> chance, it was incremental, but with no practical survival value. > >> > >> graywolf wrote: > >> > >>> No, you are missing a point there, Peter. Non-survival traits do away > >>> with a line. Survival traits give it a boost. But traits that do not > >>> affect survival are a dice roll, which is the point you are missing. Pure > >>> chance, in other words. > >>> > >>> > >>> > >> -- > >> All dogs have four legs; my cat has four legs. Therefore, my cat is a dog. > >> > >> > >> -- > >> PDML Pentax-Discuss Mail List > >> [email protected] > >> http://pdml.net/mailman/listinfo/pdml_pdml.net > >> > >> > > > > > > > > > -- > All dogs have four legs; my cat has four legs. Therefore, my cat is a dog. > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
