Dr.GH

Bill, there are a number of hunter/gatherer populations today so you needn't worry about
babies from remnant populations. Most of the differences you assert are nutritional,
medical both pre- and neonatal.

theyeti, clinical depression is one of the human stress responses. Further, it is one that is
common to all mammals. The so called "vegetative" signs of depression are in fact
functional responses to famine and are also related to hibernation.

There was a major change in the types, and complexity of artifacts produced
between the Paleolithic, and Mesolithic. This could very possibly have been the material
marker of an evolutionary change in the neural organization of the brain; one that had
little or no osteological component.

However, a Homo sapien child of 10k years ago would be fully equal to modern
populations.

[ January 25, 2002: Message edited by: Dr.GH ]</p>

theyeti

It would be hard to study directly becuase they're relatively few hunter-gather tribes left, and those have been pushed onto marginal lands and been subjected to non "natural" conditions (i.e. those that we would find 10K years ago). But I think a "transplantation" study would be instructive, assuming it's ethical.

But I don't think it's too much of a stretch to say that a Pygmy baby, to take a random example, would be satistically more likely to encounter difficulty if raised in "civilization". I'm not claiming here that the range of behavioral tendancies under genetic control is outside the range from 10K years ago, just that it's probably shifted quite a bit. It's hard to believe that it hasn't.

theyeti

theyeti

Right. But my point is that since we are in stressful situations that are more likely to promote depression, so the selective pressures have changed. I assume that depression is a functional response to those conditions, but it can be highly dysfunctional in the modern environment (of course, mabey this doesn't apply until post industrial revolution). Also, as for famine, it became much more common after the neo-lithic when agriculture replaced hunting and gathering. I just think that these drastic changes in environment have put new selective pressures on humans that have changed allele frequencies, or at least are doing so now.

Equal in what regard? There is a tremendous ammount of variation within modern populations. I don't think that a 10K years ago infant would fall outside of that range of variation, but it would be more likely to be at one end of the range of quantifiable behavioral traits.

theyeti

Baloo

Actually, I think most of you are twisting this question into an overly simplified false dichotomy, whereby you are both right and wrong at the same time.
It seems a pretty safe assumption that, in general terms, the rise of intelligence of our ancestors has been gradual, and has been going on since our ancestral split with the chimpanzee lineage, which probably occured about 2 million years ago. So to me, the question is: if we take the difference of intelligence between the average modern man, and that of the modern chimpanzee (which we will assume is at least as intelligent as the common ancestor between man and chimpanzee from 2 million years ago), divide that difference in intelligence by 2,000,000 years, then multiply it by 1,990,000 years, would we expect to see a clear difference?

For perspective only, let me provide this crude example: if the average modern chimp has an IQ of 20, and the average man an IQ of 100, the average IQ of man 10,000 years ago would be about 99.6.

You cannot expect to take an arbitrary individual from a population with an average IQ of 99.6, put it into a population with an average IQ of 100 (stdev = 15), and hope to tell it apart based on intelligence. However, if we took 10,000 babies from 10,000 years ago, and raised them today, I think you would see a statistically significant deviation between their intelligence and that of modern babies.

tronvillain

You do realize that we're not limiting this discussion to "intelligence"? I see no reason to predict an average increase in intelligence - there could easily be an average decrease.

Dr.GH

Theyeti, "Equal in what regard? There is a tremendous ammount of variation within modern populations. "

And what variation would that be? The overwhelming result of over 100 years of physical anthropological study is that there is very little variation between contemorary modern human subpopulations.

Your observation about modern hunter/gatherer populations being severly marginalized is a good point. It is a consern amoung anthropologists, and archaeologists that we do not have very good ethnographic descriptions of hunter/gatherers from a wide range of environments. The northwestern margin of North America, Australia, Amazonia and the Indonesian archipelago provide our best data.

comradeBillyboy

given the natural diversity of brains, or any other living thing, i think it would be quite difficult to detect any specific evolutionary change. if our knowlege of the brain is sufficent and we could adequatly define evolutionary criteria then long term population studies might be conducted and perhaps a supportable answer to the question would result. perhaps such a study is feasable now; i don't know, but at the moment, i don't think there is enough data to form a reasonable theory.

tronvillain

Dr.GH, I believe theyeti was referring to variation within humans as a whole, and not to variations between groups.