Wednesday, February 13, 2008

give an ape a bone...

Can anyone tell me how a materialist would use Evolution to explain why human males do not have a "baculum"-- a bone in their penis-- like their "ancestors"?

Thanks in advance!

2 Comments:

At February 13, 2008 at 10:26 PM , Blogger William Lang said...

My understanding of evolution is that attributes or characters are lost when they are unneeded. For example, eyes in cave-dwelling creatures, or flight in birds confined to islands lacking predators. Other characteristics are lost when there is a good reason for jettisoning them. One example of this is teeth in birds. Modern birds of course lack teeth, but the ancient Archeopterix (which had feathers and could fly) had teeth, claws on its forelimbs (wings), and a long (bony) tail. Presumably, birds lost their teeth because of the compelling need to reduce weight to facilitate flight. By the way, it's been found that a certain genetic mutation will cause teeth to begin to grow in chickens, teeth resembling alligator teeth (alligators are the nearest living relatives to birds).

Of course, this begs the question as to why humans lost their penis bones: the real question is why they became unneeded in our species. But Dawkins has another theory: sexual selection. I lack the expertise to comment on that theory, but I gather that the evolution of sexual traits (such as the extravagant display of the peacock) is still poorly understood.

By the way, there are other significant differences between humans and great apes in sexuality. Chimpanzee males form hierarchies, and the alpha male has first access to the females (the females form their own hierarchy). Humans of course instead tend to pair-bond. This has the effect of reducing competition among males for females, and therefore allows much greater cooperation between human males. Humans share the chimpanzee behaviors of killing and war (chimps regularly hunt and kill chimps from rival bands) but the critical feature of humans is their tremendous capacity for cooperation. Humans will treat individuals unrelated to themselves as if they were kin (they will protect such individuals and cooperate with them). This human trait of course makes possible civilization (living in large communities).

 
At February 14, 2008 at 10:28 AM , Blogger Eric Schansberg said...

Thanks William!

With respect to the question I asked, the key phrases you used were: "presumably", "begs the question", and "still poorly understood".

Beyond that, thanks for the info on Archeopterix, the comparison of human vs. great ape sexuality. Interesting observations!

 

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