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Monday, January 14, 20081200348266

When we began

When "we" began is a topic that's the subject of a lot of research but (considering the mutual hostility toward biological science by all parts of the political spectrum) not much publicized. The first physically modern humans probably weren't like us at all, except in outward appearance.

"Behaviorally modern humans" began about 80K year ago -- this marks the first time that humanity is able to circumvent the blockade imposed on us by Neanderthals and Homo Erecti (Peking Men). Before circa 80K, the boundary of our species was determined by climate so, for example, Palestine was settled by Neanderthals, taken by physically modern men, and then retaken by Neanderthals -- all basically a function of the temperature. 80K years ago, more or less, humans build boat, go along the coast of Asia (but apparently not entering -- Peking Men probably ate us) and got to Australia.

"Culturally modern humans" seem to have started roughly 10K years ago, when inhabitants of the fertile crescent -- who had not yet discovered farming -- started living in cities. Consider that: for the first time, our species was living in high-density because we wanted to -- because it was better to be with our fellows than be out in packs, even though we were still hunting animals and gathering plants. This doesn't mean that behaviorally modern humans would not be capable or willing to live in cities, but the for the first time a metastable equilibrium toward city life existed.

In A Farewell to Alms, Greg Clark argues that what might be called economically modern man finally emerged 200 years ago, in England, after an extremely long period of intense malthusian selection. Clark's politically smart enough to be coy about the mechanism, but it's pretty clear he's talking about genetic natural selection. (Malthusian selection really only operated in situations where starvation was a major cause of death. Among the Plains Indians, high rates of violence guaranteed there generally was enough food for everybody. So the Sioux were taller than some of the European settlers, because their more violent society was healthier for those who lived.)

Domestication is a continual process that produces dumber, weaker, and friendlier creatures. Our species is undergoing domestication -- at different rates in different places and in different times.

tdaxps_new_map_md


This is why shrinking the Gap is more important than global warming: climate change is easier to deal with the later you put it off, because economic and technological growth compounds, making the solution easier every year. Shrinking the Gap probably gets harder every generation, as populations continue to diverge. Further, as populations are much larger nowadays (increasing the rate of natural selection), every generation of divergent evolution now is worse than a generation, say, ten-thousand years ago.

16:04 Posted in Science | Permalink | Comments (11) | Tags: domestication

Comments

Regarding natural selection, plagues may also be considered Malthusian checks.

Posted by: Moon | Monday, January 14, 2008

Moon,

Clark argues that East Asia had higher populations than Europe because of better sanitation. Of course, this meant lower living standards in East Asia too -- with fewer people, Europeans had a richer diet and were less likely to die of starvation.

Posted by: Dan tdaxp | Tuesday, January 15, 2008

OK, this one I'll bite on.

The population is also compounding. I'd like to see your calculation where human effect on environment intersects with technological ability to confront it.

Posted by: Aaron | Tuesday, January 15, 2008

Aaron,

Economic growth is faster than population growth or growth in resource consumption.

Hence it's cheaper to "buy back" the effects the longer you wait.

Posted by: Dan tdaxp | Tuesday, January 15, 2008

Some of the physical differences can be also explained by quality of diet. Europeans were getting the required calories to survive, but from poor sources. A partial explanation of the growth of heights in Europe and among Europeans and Africans in N. America is improving diet, this is how Michael Jordan can be 6'6" while no one in the two generations before him surpassed 6 foot.

Posted by: ElamBend | Tuesday, January 15, 2008

ElamBend,

"Some of the physical differences can be also explained by quality of diet."

Agreed, this is my point. As I wrote in the post:

"So the Sioux were taller than some of the European settlers, because their more violent society was healthier for those who lived."

Less people to divide available calories between = better diet = healthier society for those who lived.

Posted by: Dan tdaxp | Wednesday, January 16, 2008

So you would posit there's no point of no return?

Posted by: Aaron | Wednesday, January 16, 2008

"So you would posit there's no point of no return?"

What are the points of no return?

Certainly they exist for both genetic/cultural divergence and climate change. But you can't say one needs to be focused on rather than the other because of a "point of no return," because both problems have it as some point.

Posted by: Dan tdaxp | Wednesday, January 16, 2008

Well, if we'll assume numerical values, I do truly wonder where the point is that we say "OK, with X climate change, we lose/gain Y food growing regions and kill/displace Z people. If population grows at A, and technology grows at rate B, when can good Christians square with it?"

That is typical Aaron hyperbole, but I guess on a blog where we examine race in genetic constructs and female intelligence by brain volume (neither of which I disagree with, damn science-blind wing of the liberal party) then surely we can say "X 3rd world country folk can die so American captains of industry don't have to take Y% paycuts."

Posted by: aaron | Thursday, January 17, 2008

Aaron,

You seem to be describing a public policy approach to climate change. This was addressed in some depth in Bjorn Lomborg's "Cool It" [1,2]

[1] http://www.amazon.com/Cool-Skeptical-Environmentalists-Global-Warming/dp/0307266923
[2] http://tdaxp.blogspirit.com/archive/2007/10/12/review-of-chill-out-the-skeptical-environmentalist-s-guide-t.html

Posted by: Dan tdaxp | Thursday, January 17, 2008

Y'know, somewhere out there, there's either a Trekkie fanfic writer or a Trek franchise writer who's trying to come up with an ideological "background" to Colonel Green--and you may've just provided at least partial inspiration to said writer.

Sorry--couldn't help recalling that when I first read this, I'd just seen a repeat of "Enterprise" on the Sci-Fi channel, featuring one of the Bad Guys watching an archival clip of a speech by Col. Green.

What timing to have seen this show, and then to read this....

Well, as I say, just a "thought"...

Posted by: Jayson | Thursday, January 17, 2008

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