Thursday, 6 January 2005

The Political Animal

Lots of consecutive political posts again. How come something truly major comes along, and after less than a week, it's inspired lots of politics?

So this isn't a political post. It's about Brains and Human Evolution. And Politics.

Cell JournalThe 29 December 2004 issue of the journal Cell contain an article that analyses the latest research on genetics and the human brain. It contains something quite unexpected. Our higher brain functions evolved unusually rapidly, implying a most unusual evolutionary pressure at some time. Basically, at one point, times were tough, and only the Intellectual Olympians survived to breed. How do we know this? By close examination of genetic changes and subtle clues in various proteins. Not my field, I'll take the molecular biologists' word for it though.

Now intelligence is good, but it's not the be-all and end-all. Sometimes a good pair of running legs is a better guarantee of survival than the ability to read Shakespeare in the original Klingon. Presence of Mind is Good, but when the Tsunami comes, Absence of Body is better. Something other than the usual menace-of-Sabre-Tooth-Tigers must have been at work, and working overtime to get so much accomplished so quickly.

It is conjectured that the evolutionary pressure is due to... Sociology. Or to put it more bluntly, Politics. Interpersonal, intra- and inter-tribal. Homo Sapiens is, after all, the Political Animal. And we now have some objective, hard evidence that there really is something rather unique about our evolutionary development, despite the relatively small difference between our own Intellect and that of our closest relatives', the other two Chimpanzee species.

From an article about this in Space Daily :
Brain Cross SectionGenerally speaking, the higher up the evolutionary tree, the bigger and more complex the brain becomes (after scaling to body size). But this moderate trend became a huge leap during human evolution. The human brain (pictured) is exceptionally larger and more complex than the brains of nonhuman primates, including man's closest relative, the chimpanzee
According to Lahn, data from the Cell paper secures humans' privileged position in the evolutionary tree. "Human brain evolution required a major overhaul of the genetic blueprint - perhaps much more so than the evolution of other biological traits," he said.

But how did human ancestors encounter an environment where selection for better brains suddenly became such a prominent force? Lahn suggests that because humans have become a progressively more social species, greater cognitive abilities have become more of an advantage.

"As humans become more social, differences in intelligence will translate into much greater differences in fitness," he said, "because you can manipulate your social structure to your advantage.

"Even devoid of the social context, as humans become more intelligent, it might create a situation where being a little smarter matters a lot.

"The making of the large human brain is not just the neurological equivalent of making a large antler. Rather, it required a level of selection that's unprecedented," Lahn said.

"Our study offers the first genetic evidence that humans occupy a unique position in the tree of life. Simply put, evolution has been working very hard to produce us humans."

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