On Sun, 23 Nov 2003, Ed Weick <[EMAIL PROTECTED]> >And I would take issue with you that we are now the same as we were >100/200,000 years ago. Stephen Mithen of the University of Reading, as >one example, argues that until about 70K to 80K years ago, our brains >were relatively compartmentalized; that is, we were a lot like cats who >think about mating and nothing else when mating, hunting and nothing else >when hunting, socializing and nothing else when socializing, etc. At the >time, our rather limited thoughts and actions were highly genetically >determined. Then something happened. The wiring that controlled all >that began to fall away and we became, as Mithen puts it, "cognitively >fluid"; that is, we could think across all of those little compartments >and use them all at the same time. The result was an explosion in >creativity and also an explosion in our capacity for mischief. Not >everybody agrees with Mithen. Some argue that a "creativity gene" arose >some 50K to 100K years ago.
Despite the substantial media coverage given to short-chronology champions like Klein, and to a lesser extent Mithen, these are not the majority view in paleo-anth regarding the rise of Homo sapiens. Molecular evidence is persistent in putting the start of the clock for our particular string of ancestors at around 150-200kya, and archaeology supports this with indications of transitional but mostly modern phenotypes in northeast africa @ 160kya, and tools along the Red Sea shore around 125kya. The thinking is that culture is a huge part of what we currently are, and the accumulation of this, in the form of sophistication in language, technology, and lore, takes a long time to develop. The effect is essentially exponential, rather like population growth - we had the essential modern mental hardware, but it took in the order of 100ky for our particular string of ancestors to build up their population to the point that they were able to develop and retain the necessary cultural tools to achieve the material trappings of modernity. Consider that the Neanderthals were in europe for perhaps 300ky with essentially the same toolkit, yet were able apparently to begin absorbing the refined tools of Homo sapiens as soon as they arrived on the scene. This indicates I think the essential mobility of culture, and its independence from creative intellectual capacity. The strong objections to the 50kya figure also refer to the current indications of human migrations. The evidence is that we were out of africa by 100kya, and heading east and south, much more hospitable places at that time than europe, which resisted our incursion until we had developed the cultural solutions to cold weather living, perhaps as much as 40 or even 50ky later. By that time we had penetrated SEasia and were working our way northeast along the pacific rim. If Mithen's timing were correct, all these people would be deprived of his eurocentric genetic advance, which is clearly not the case. Whatever happened, appears to have happened >to all of us alive at that time in just a few generations, and it would >seem that there weren't very many of us. As is suggested by the unique >similarity of human DNA among primate species, there may only have been >some 2,000 of us, the survivors of some natural disaster barely managing >to stay alive somewhere in Africa. The puzzle of our genetic lack of diversity is not resolved, as it appears to have developed while we were in africa. Apparently we chose not to, or were prevented from interbreeding with the extant Homo lineages in africa, and when we had developed a distinct gracile phenotype, we appear to have displaced, rather than absorbing into each other hominid type we encountered as we spread south into africa and north into the rest of the world, spreading our meager but potent genetic legacy. -Pete Vincent _______________________________________________ Futurework mailing list [EMAIL PROTECTED] http://scribe.uwaterloo.ca/mailman/listinfo/futurework
