Viraj's Weblog

I've been reading Almost Chimpanzee, a rather long book comparing humans to chimpanzees, and notably, their differences. Many books point out similarities, but this one takes a different approach. There are some interesting findings in it. For example, think the flatness of our face helped survival? Consider modern dentistry:

In the mouth, the chimpanzees and humans have the same "dental formula": thirty-two teeth at adulthood, with two incisors, one canine, two premolars, and three molars on each side, top, and bottom. In addition to the famously large canines, the last molars - the wisdom teeth that erupt at adulthood - get much more space in chimpanzees than in humans because chimps have an elongated face. "In humans, before modern dentistry, eruptions and the impaction of wisdom teeth followed by septicemia was a major cause of death," Gagneux said. "There's a huge cost to having shortened the face. You can kill yourself by trying to grow the tooth that defines you as an adult."

Also consider the baculum, which in modern times has been replaced by Viagra:

Gagneux, who specializes in reproduction, noted that chimpanzees have a tiny bone in the penis, the baculum, that is absent in humans. In the Selfish Gene, the evolutionary biologist Richard Dawkins suggests that human males lost this bone in something akin to the Trench Coat theory of bipedalism. The baculum helps maintain an erection, which makes it useful especially as males age or develop mental problems, diabetes, or neurological complications. But for females selecting a mate, the baculum hides problems. "It is not implausible that, with natural selection refining their diagnostic skills, females could glean all sorts of clues about a male's health, and the robustness of his ability to deal with stress, from the tone and bearing of his penis," writes Dawkins. "But a bone would get in the way!"