25 September 2008

Self-made Man

Not sure about this:
The most intriguing form of relaxed selection...occurs when an animal actively creates a shield against natural selection. This so-called Baldwinian evolution has played a particularly important role in the evolution of our own species. For example, the technological innovations of producing stone tools and cooking meant that our ancestors no longer had to chew tough vegetation and meat. This reshaped the way we look...[notably] a radical reduction in large flat molars, thick enamel, robust face and jaw structure and powerful jaw muscles...Then came agriculture, which made foods even more palatable, relaxing the selection pressures on our digestive system. As digestion became easier, more energy was available for other purposes, especially for building and running a larger brain. Our ancestors would have used this increased cognitive capacity, in turn, to devise more technological and cultural innovations to further shield them from the pressures of natural selection.
-- from Freedom from selection lets genes get creative by Christine Kenneally New Scientist, 28 Sep.

No comments: