Chimpanzees living in the West African savannah have been observed fashioning deadly spears from sticks and using the tools to hunt small mammals -- the first routine production of deadly weapons ever observed in animals other than humans.
This is not the first time we've seen chimps use tools, nor the first time we've seen them use tools against prey.
Scientists have documented tool use among chimpanzees for decades, but the tools have been simple and used to extract food rather than to kill it. Some chimpanzees slide thin sticks or leaf blades into termite mounds, for example, to fish for the crawling morsels. Others crumple leaves and use them as sponges to sop drinking water from tree hollows.
But while a few chimpanzees have been observed throwing rocks -- perhaps with the goal of knocking prey unconscious, but perhaps simply as an expression of excitement -- and a few others have been known to swing simple clubs, only people have been known to craft tools expressly to hunt prey.
What is the lesson of this research? Well, the lesson the anthropolotists were interested in is that the females are the majority (by 2/3) of tool makers and users. But I can see people getting worked up over the fact that chimpanzees are sometimes violent predators. I found a blog post where the blogger asserted that the human researchers taught the chimps this technology. Despite the unlikelihood that any researcher would do such a thing, the fact is that chimps are known to kill already. There's at least one documented case of infanticide, a case of cannibalism, and plenty of instances of chimpanzees hunting other animals.
In any case, I think the clear indication is that chimps and humans aren't so different after all. Humans got taller and smarter, but we've lost none of the survival instincts that we had millions of years ago when our ape ancestors and the ancestors of the chimps went their separate ways. Attitudes towards the apes are often tainted by a benevolent sort of anthropomorphism in which even some scientists view them as our purer, more innocent cousins. Innocent they may be, but not of killing. That doesn't degrade them somehow, or make them less.
Humans and chimps are more alike than any scientist would have professed 150 years ago. Many would not have believed in this behavior a mere 30 years ago, or at least before Jane Goodall's famous studies. What this implies about what it means to be human is a question for the biologists and philosophers, but what it says to me is that the only way to separate ourselves from the beasts is to make a choice to renounce violence and rid it from ourselves.
When you see a picture of a chimp carrying a chunk of meat it ripped off its prey, or bludgeoning a Bush Baby to death, you can't blame it for acting that way. It's a chimp. But when you see humans killing humans, or read stories about humans dumping a bag of puppies in the lake, you should question the humanity of anyone who could be that beastly.