Have you ever wondered about the the close evolutionary relationship between chimpanzees and human beings and why we have evolved as we have and the chimpanzee has not? After the split of the shared ancestry of chimpanzees and humans, about 5 million years ago, the bipedal hominids or Australopithecus, formed our evolutionary foundation of modern man. What were these Australopithecus like? Were they hunters or gatherers or scavengers? What clues do we have besides fossil records to better understand our ancestors. Well, the Chimpanzees living in West Africa may provide some clues to the evolution of our own behavior. As reported in the Washington Post today, the first routine production of deadly weapons has been observed in an animal other than human. I was both surprised and intrigued by this story.

Primatologists and anthropologists have for years believed that wild chimpanzees were strict vegetarians and that the biggest difference between higher primate animals and humans was that only humans were capable of producing and using “tools”. But scientists observing chimps in the wild have learned that not only is it clear that meat is a natural part of the chimps diet but that chimps have remarkable skills at using tools to hunt for this meat. In the past, chimps have been observed to use tools to extract food such as to crack open hard-shell seeds and nuts with a stone hammer against a stone or wooden anvil, and to break off a long grass stalk or a reed to lure delectable termites out of a log or termite mound (requiring much skill and finesse, I might add). But, scientists have never observed a non-human animal using a tool to kill its prey.

But what has been reported today is a chimp fashioning deadly spears from sticks and using the handcrafted tool to hunt small mammals. This is the first observation of an animal other than the human, in pre-meditating the use and production of a tool. Chimps were observed tearing off the side branches of long straight sticks and peeling back the bark. And, using their hands and teeth, they sharpened the stick to create the weapon. Then, grasping the weapon in a firm grip, they jabbed aggressively into tree-branch hollows where bush babies live. Intermittently, they would withdraw the stick and lick it to make sure they had “caught anything”. Assured that they had cornered their prey, they would repeatedly stab and then eventually remove and eat it.

According to Craig Stanford, a primatologist and professor of anthropology at the University of Southern California, “these new observations are stunning; really fashioning a weapon to get food — I’d say that’s a first for any nonhuman animal.” While a few chimps have been observed throwing rocks — perhaps with the goal of knocking prey unconscious or simply as expressions of excitement, and a few others have been known to swing clubs — but only humans have been known to craft tools expressly to hunt prey.

What does this tell us? With the environment of this particular West African savannah being very much like the one in which the Australopithecus evolved, perhaps chimps are on a very similar path in their evolution as humans took. Chimpanzee behavior of this type might offer a window of understanding of our own early human behavior and the earliest use of wooden weapons. In the chimp’s evolutionary use of weapons, could it be that this type of violence is hard-wired? Maybe even our own potential for violence is hard-wired? Scientists wonder if chimpanzees are using these new weapons to be vicious and murderous, just as humans can be. And, with chimp behavior being so similar to our own, scientists are wondering how long before chimps begin stabbing each other and perhaps even others.

Although, from all my readings on this subject, what convinced me that chimps’ evolution is on the same path as human evolution is how meat is used by the chimps. In American Scientist, it has been observed that male chimpanzees revealed their prowess to other members of the community by using meat for political and sexual dominance. The Japanese primatologist Toshisada Nishida and his colleagues in the Mahale Mountains showed that “the alpha male Ntilogi distributes meat to his allies but consistently withholds it from his rivals”. Such behavior, they suggest, “reveals that meat can be used as a political tool in chimpanzee society.” And, a begging female does not receive any meat until after the male copulates with her (even while clutching the freshly killed carcass). Hmmmm….it just goes to show you that when it comes to human or chimp evolution — some things just never change.