dimossi

Some friends and I were discussing evolution and there was some disagreement about a certain idea.

A few of us have stated that our brains haven't really evolved in 50,000 years or so and that if we were able to take a baby born 10,000 years ago and zap it to our present day and then raise it in a regular family, as any other child, that it would be mentally undistinguishable from other children.

A few in our group said they did not believe this would be the case. They stated that they believed that our brains have physically evolved in some way. We disagreed stating that our appearence to be smarter is just due to the cumulative knowledge that we have gained throughout history and knowing how to then apply that knowledge toward more advanced goals.

I would like to hear what you all think.

David Gould

I do not think 50,000 years is long enough for significant evolutionary change to have occurred. There may well be some differences but they would (in my opinion) be so small as to be basically irrelevant.

However, I too would be interested if I am correct in my thinking.

Vorkosigan

Given that human cognitive facilities cover such a broad range, even if it were perceptibly different, would it fall outside that range? I think it would be tough to tell.

Michael

tronvillain

Actually, I think that ten or fifty thousand years is probably long enough for fairly significant evolutionary changes to occur. Considering the apparent lack of significant brain differences between distant populations it seems unlikely that they have occurred in the case of the brain.

Boshko

The only real differenes would stem from differences in the nutrition of the mothers during pregnancy...

Bill

This question goes back to the more basic question of whether nature or nurture is the source of the characteristics which humans display. Unfortunately, the actual answer is that a little bit of both is quite important.

I would assert that 10,000 years is plenty for substantial evolutionary changes to have occurred within the human genome. The agricultural revolution in human behavior occurred roughly 8,000 to 16,000 years ago. So, a 10,000 year old baby could conceivably come from one of the remaining "hunter/gatherer" tribes, and if that were the case, I would expect there to be some substantial evolutionary differences because I also expect that there was a genetic componant to the agricultural revolution.

Minor evolutionary changes can be easily discerned within historical times. For instance, just within the past few hundred years, people have gotten (on the average) quite a bit taller, and live (on the average) far longer, both due to better nutrition (on the average).

Still, it is an interesting question to contemplate.

== Bill

theyeti

All we know about the brain in the last 10k years is that it's size and shape haven't changed (perhaps due to limitations imposed by the birth canal). But that doesn't mean that behavioral patterns under genetic control haven't changed. I would suspect that they have changed significantly, and continue to do so at a relatively rapid rate today. The selective pressures imposed by civilization are quite different than those of hunter-gather societies -- many of our quirks and our penchant for depression are likely the result of this. I would imagine that a 10,000 year old baby raised today would have a greater chance of behavioral problems; specifically agression, depression, and difficulty in many "modern" social settings. (Of course, this describes a lot of us )

theyeti

kwigibo

I thought human intelligence evolved for those primitive hunter-gatherer lifestyles, and intelectual abilities haven't changed since then, just that we have such versatile cognition that we have adapted our existing intelligence to all eventualities faster than natural selction can do it for us.

Regardless, i think we can all agree that selective pressure on the human species has been rapidly decreasing since the birth of civilistation

tronvillain

Bill:
Do you realize that when people attribute these changes to better nutrition they are saying that it is not an evolutionary change?

tronvillain

So theyeti, are certain native populations less suited to living in "civilization"? It's possible, but I think you may be understimating the plasticity of the brain and overestimating the strength of the selective pressures.