Thursday, February 22, 2007

The armed chimpanzee

Can you hear the fundies screaming? If you can't, you will soon. A double whammy has just been published in Current Biology. Jill Pruetz and Paco Bertolani have been studying Savannah chimpanzees in Fongoli, Senegal. What they discovered was more than a little significant. The Fongoli chimps hunt with weapons. The summary (emphasis mine)
Although tool use is known to occur in species ranging from naked mole rats [1] to owls [2], chimpanzees are the most accomplished tool users [3, 4, 5]. The modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. Here, we report the first account of habitual tool use during vertebrate hunting by nonhumans. At the Fongoli site in Senegal, we observed ten different chimpanzees use tools to hunt prosimian prey in 22 bouts. This includes immature chimpanzees and females, members of age-sex classes not normally characterized by extensive hunting behavior. Chimpanzees made 26 different tools, and we were able to recover and analyze 12 of these. Tool construction entailed up to five steps, including trimming the tool tip to a point. Tools were used in the manner of a spear, rather than a probe or rousing tool. This new information on chimpanzee tool use has important implications for the evolution of tool use and construction for hunting in the earliest hominids, especially given our observations that females and immature chimpanzees exhibited this behavior more frequently than adult males.
Evolution. The dirtiest word in the fundie vocabulary. But there is something even more significant.

When Pruetz and Bertolani were making their observations they discovered something even more amazing. While all the chimps hunted as a group, it was the females who selected the branch of a tree, trimmed it, sharpened it into a spear and then employed it as a weapon. The scientists have a reason for that. The females, being smaller and less powerful than the males, have employed a technical device to allow them to compete equally with the hunting males. In short, because the females do not possess the physical strength of male chimps, they use their brains to a greater degree than the males.
Pruetz noted that male chimps never used the spears. She believes the males use their greater strength and size to grab food and kill prey more easily, so the females must come up with other methods.

The researchers are suggesting that the behaviour of the Fongoli chimps may reflect tool and weapon development by early humans. And that would suggest that women were the inventors and employers of the first hunting weapons.

This all indicates that this four year old concept may have a lot more merit. Since humans and chimps share 99.4 percent of the same DNA, perhaps it's time we showed them a little more respect. After all, in a few million years, if we don't blow the place up, chimps could be going into space without the help of humans.

Although, I'm sure there are some who would disagree. Let the screaming begin.

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