When asked what one thing sets humans apart from even the smartest and most advanced animals, most people (leaving a religious argument aside) would say that our use of tools best shows our advantage over animals. While there are a few examples of chimps and birds using rudimentary tools for simple tasks, our ability is so advanced, we even fashion clothing to wear our tools wherever we go – flouting our intelligence and manual dexterity to passing creatures. Unfortunately, our tool-based dominion over all other creatures has been called into question … and it looks like we were not the only species to learn how to use tools. In fact, we probably weren’t the first either. Archaeologists in Kenya have uncovered stone tools dating back around 2.9 million years … and the users of those tools were not ancestors of Homo sapiens. Even more ego-deflating – the tools were found in a primitive tool-making factory where these hominids used tools to make better tools for others. Does this change everything? Are the animals gloating?
“Oldowan tools, consisting of stones with one to a few flakes removed, are the oldest widespread and temporally persistent hominin tools. The oldest of these were previously known from around 2.6 million years ago in Ethiopia, and by 2 million years ago, they were found to be quite widespread.”
In a new paper published in the journal Science, Tom Plummer, a paleoanthropologist at Queens College and lead author, explains how Oldowan tools – named for the site of Olduvai Gorge in Tanzania, where in the 1930s archaeologist Louis Leakey found the first of these tools – have been thought to date back 2.6 million years and were linked to early hominins of the Homo genus that are related to or are direct ancestors of modern homo sapiens. The earliest known stone tools date to 3.3 million years old and were found at site Lomekwi 3 in Kenya, but those were primitive compared to Oldowan tools. However, they were also attribute to human ancestors. While how tools developed is a mystery, the idea that ancient humans of the homo genus invented them has remained a constant.
That is, until paleoanthropologist Emma Finestone, from the Cleveland Museum of Natural History, helped excavate an ancient hippo skeleton at a dig site in Nyayanga, Kenya. The skeleton and other bones at the site showed signs of butchering - cutmarks from tools – and the diggers soon found stone blades used to cut meat and plants. Since the site was dated to about 2.8 million years ago, the archeologists expected to find remains of the butchers – and they did. However, these were not the butchers they were looking for.
“When we found the Paranthropus molar, it got really, really exciting.”
What Firestone and the team uncovered was the tooth of a member of the extinct hominin genus Paranthropus, which is believed to contain two species: P. robustus and P. boisei. (Photos of the tooth and the tools can be seen here.) Paranthropus skulls found before were large, with gorilla-like features in the jaw area suggesting they had strong chewing muscles, and wide teeth which were used for grinding. Also, other characteristics indicated Paranthropus like soft foods, so paleontologists assumed they didn’t need tools for killing, butchering or eating animals. That was supported by the assumption that Paranthropus was more apelike than human and did not possess the mental ability to make and use stone tools. That molar under the hippo skeleton upended all of those previous assumptions.
“They are not newbies—they have bashed rocks together before. This hints at an earlier stem to the Oldowan.”
Peter Ditchfield, a geologist at the University of Oxford who helped date the fossils, says in the press release that there is more to find … this site shows that the owner of the molar was already skilled at knapping – using one stone to chip off flakes from another to make it sharp for cutting and stabbing. The earliest known human ancestor with this ability to make Oldowan tools is Homo habilis. Make that “was.”
“Typically, it’s thought that the smaller-toothed Homo would have benefited from making stone tools that assisted in processing food outside of the mouth, whereas Paranthropus was typified by processing its food entirely with its teeth, using its large chewing muscles. When our team determined the age of the Nyayanga evidence, the perpetrator of the tools became a ‘whodunnit’ in my mind. There are several possibilities, and except for fossilized hand bones wrapped around a stone tool, the originator of the early Oldowan may be an unknown for a long time.”
Study coauthor Rick Potts, a paleoanthropologist at the Smithsonian National Museum of Natural History in Washington, DC, tells CNN that the first ancient hominin to invent tools is a mystery once more. He also marvels and the sophisticated ability of the Paranthropus based on the remains and artifacts found at Nyayanga. He compared the sharp stone flakes to lion’s teeth, and the large hammerstones to the grinding molars of elephants. This indicates these Paranthropus members could obtain a variety of plants and animals to eat, and the tools showed that they were skilled in preparing them.
“(The tool kit was) the first simple food-processor.”
While the stone tools showed that Paranthropus were experienced chefs, the tools would have been ineffective for hunting. Since none of the bones showed signs of hunting, the paleontologists conclude that these ancient human relatives butchered hippos that were already dead. That still would have made them alpha hominins of their time – those large amounts of protein and fat gave them stronger bodies and fed the development of bigger brains.
If Paranthropus were so smart, why didn’t they become the dominant species instead of Homo? The evolution of Paranthropus is still not scientifically agreed upon. Some researchers think P. aethiopicus appeared 3.3 million years ago on the Kenyan floodplains of the time. Other debate whether Paranthropus and Homo split as they evolved from Australopithecus. If that happened, it is possible that climate change - a drying period 2.8–2.5 million years ago in the Great Rift Valley – caused Homo to move to the open savanna areas while Paranthropus went to the forests, which were dying off from the drought. Even with their tools for providing a variety of foods, the drought made them unavailable and Paranthropus went extinct. While that makes sense, it is not accepted by all scientists.
Archaeologist Sonia Harmand of Stony Brook University, who was not part of the study, proposes one more controversial theory:
“We’re starting to see … lots of different species around that could have been able to make stone tools. I like the idea that they might have learned directly from each other.”
Could Paranthropus have learned how to make and use tools from the species of Homo and Australopithecus which lived in Kenya at the same time? If ancients human could learn to share and play well together, why can’t we?