>From Mr. Smith:
> Hi All, 8-6-09 > > On Tuesday, 7-28-09, I visited the Cleveland Museum of > Natural History; the Darwin exhibits were outstanding. > One of the best was an interactive display examining the > effects of selection for a larger brain. This tended to > require a larger skull, which then required larger hips > to birth. But if the hips get larger and larger, the > homonid can't walk -- very negative for natural selection. > > So something has to give. In this case, there was > selection for a smaller face so that the face would > not take up so much of the skull. But the smaller face > resulted in problems with our 32 teeth: There was not > enough room for the third molars (the wisdom teeth) > -- in general a mess with braces a tooth extractions. > This is not a fall from grace or original sin; but it may > feel like it. Everyone in my family was born with wisdom teeth, except me. The dentist still ended up extracting teeth because I didn't have enough real estate. I must be one of those mysterious planned intelligently-designed throw-forwards. I wonder how much I can milk my "advanced" genetic heritage for. ;-) > There may be some selective advantage for an ability > to commit genocide on hominids (one thinks of William > Golding's "The Inheritors"); and we were so "shocked" > whan Jane Goodall found that chimps had the same talent. > This is almost funny, except now we have atomic weapons > and germ warfare. > > Genocide probably does reduce genetic diversity; but the > more devastating "pinches" have been acts of G_d, such as > the eruption of Toba 70,000 years ago or the Tunguska-type > event that probably plunged the Northern hemisphere into > the Younger Dryas cold spell 12,900 years ago and destroyed > the Clovis culture. These things are unhappy events from > the viewpoint of the victims, but they merely illustrate > how easily such a cobbled-together species as ouselves > could join the 99% of all species that no longer exist. Natural Acts of God may have been responsible for most genetic pinches in our planet's past. However, due to our specie's propensity to develop better clubs and spears I suspect we may soon give Mother Nature a good run for her money. Regards, Steven Vincent Johnson www.OrionWorks.com
