I love any story that pushes human behaviour further back in history.
These stories are very common in anthropology as they are in paleontology. This is because the fossil record is incomplete, so if we have an instance of something, say feathers on a dinosaur, it is a safe bet it is not the oldest instance of the thing it represents.
In science, however, we do not call things certain until we have concrete evidence for it, so despite the commonness of these stories, they are always exciting.
Such was the case last week when researchers announced they had unearthed the oldest stone tools yet discovered. I was thrilled. At 3.3 million years old, the hammers and cutting instruments found in a dried up riverbed in Kenya places the development of tools beyond even the earliest appearance of the genus Homo.
The only hominids around back then were Australopithicans, precursers to the Homo genus. The discovery has serious implications for how we view ourselves.
“This discovery challenges the idea that the main [characteristics] that make us human—making stone tools, eating more meat, maybe using language—all evolved at once in a punctuated way, near the origins of the genus Homo,” said Jason Lewis, a Rutgers University paleoanthropologist and co-author of the study.
This is not really surprising. There are many things that challenge that idea. In fact, repurposing objects for use as tools, is something a surprising number of species do.
In 1960, Jane Goodall observed wild chimpanzees not only repurposed leafless twigs to “fish” for termites, but actually stripped leafy twigs of their leaves to make the tool.
Bonobos, a subspecies of Chimpanzee that exhibits even closer human-like characteristics can be taught to make stone tools.
Chimpanzees are, of course, our closest living relatives, descendents of a common ancestor, so that is not overly surprising either. In fact, all of the Great Apes have been observed using and even making tools. Their uses include hunting; processing nuts, fruits vegetables and seeds; collecting water; and making shelter.
Birds are also prodigious tool users, particularly the Corvids, which includes crows and ravens. Many of these birds use the same trick as Chimpanzees to collect insects.
Urban crows in Japan have been observed dropping hard-shelled nuts on pedestrian crosswalks to have them run over by cars. They then retrieve the nutmeat. That demonstrates higher level cognitive ability.
Other crows have been shown to repurpose bread by dipping it in the water to attract fish.
The list goes on. Elephants, dogs, bears, whales and dolphins, sea otters and beavers exhibit some form of tool use.
Surprisingly, even some reptiles and fish do it.
Perhaps not so surprisingly, some cephalopods (octopi and squid) which are known to be quite smart are also among the tool-using species.
It’s a fascinating subject, but not to dismiss our uniqueness, no other animals do it anywhere close to as well (or nearly as much to their own detriment) as we do.
Still, one must walk before one runs, and the most recent discovery of hominid tools represent baby steps.
In fact, at first glance, many of the tools appear to just be broken rocks. A close examination, however, reveals the purposefulness with which the rocks were modified and suggest the purpose for the tools was processing food, cutting meat and cracking nuts.
In total, the scientists recovered 147 artifacts in the same area, another indication of their legitimacy as tools.
As with many scientific discoveries, this raises as many questions as it answers.
Who made them? What relation is the maker to us? What is the place of the tools in the tool-making lineage?
I’m looking forward to the many years of analysis to come.
