by Brenden Higashi
Rhonda Quinn, Ph.D., Seton Hall’s new biological anthropology professor, is part of a research team whose study was published on the front page of the prestigious “Nature” magazine in September.
Quinn and her team’s research in the Turkana Basin of Kenya unearthed and dated the world’s oldest known set of Acheulean handaxes. Previously thought to have emerged around 1.4 million years ago, the Acheulan handaxe is a bifacial stone tool that is believed to have been a sort of “Swiss-Army knife” of the era, according to Quinn.
The set dated by Quinn and her team is approximately 1.76 million years old. This new date has many implications for the way scientists and anthropologists understand the world.
“Pushing back (the date of) those stone tools actually brings up more questions than we have answers for,” Quinn said. “Previously, the oldest well-dated site was about 1.4 million years ago, and at that time, in Africa, we really only have one hominid species, which is Homo erectus.”
According to Quinn, there are more hominid species in Africa at the new date for Acheulean handaxes. Previously, the Oldowan industry was the only known tool kit at 1.7 million years ago.
“At this time, there are probably three if not more hominids on the landscape, which brings up the question: how many tool users do we have,” Quinn said. “How many branches do we have? We have all of this morphological variation, but now we also have this behavioral variation. And so now is it Homo habilis using Oldowan and Homo erectus using Acheulean? Is it a species-level difference? Or is Homo erectus is the only tool user who is using both Oldowan and Acheulean?”
As a result of the new date for the emergence of the Acheulean, Quinn says there are new questions about the dispersal of hominids out of Africa.
“We don’t see widespread handaxe use until 600,000 years out of Africa, some researchers push that to 1 million years out of Africa,” Quinn said. “If (the Acheulean) is a sort of Swiss Army knife and it helps you in so many circumstances, why didn’t Homo erectus take it during dispersal? There is a real question now about competition and whether or not the individuals who stayed in Africa and had the Acheulean were the ones outcompeting everyone else.”
According to Quinn, this calls into question the very idea about why hominids began their dispersal out of Africa.
“Maybe it’s not this curious intrepid Homo erectus that, armed with the Acheulean handaxe, went and tapped into new resources all over the world, or at least Asia and Europe,” Quinn said. “Rather, maybe it was the ones who could compete for food resources who stayed in Africa and those that dispersed initially at least, may have been looking for less competition.”
“We think of dispersal as the ‘successful’ thing to do,” Quinn continued. “If you can disperse, you must be better than sliced bread. Your brain’s bigger; your body’s bigger; you are expanding your home range; you are expanding into new environments; you are versatile. Well, maybe, that’s not what is happening at all.”