The earliest evidence of human ancestors using hunting and scavenging techniques has been found by researchers from working in the field in Africa.
Working at the 2 million-year-old Kanjera South (KJS) site near Lake Victoria in Kenya, researchers found evidence of scavenging amongst early humans. The site contains three large, well-preserved, stratified layers of animal remains.
The site contains a large number of isolated heads of wildebeest-sized antelopes.
Compared to small antelope carcasses, the heads of these somewhat larger individuals are able to be consumed several days after death and could be scavenged, the researchers report. Even the largest African predators like lions and hyenas were unable to break teh skulls open to access their nutrient-rich brains.
"Tool-wielding hominins at KJS, on the other hand, could access this tissue and likely did so by scavenging these heads after the initial non-human hunters had consumed the rest of the carcass," said Joseph Ferraro, assistant professor of anthology at Baylor University and lead author of a recent study at the site.
"KJS hominins not only scavenged these head remains, they also transported them some distance to the archaeological site before breaking them open and consuming the brains. This is important because it provides the earliest archaeological evidence of this type of resource transport behavior in the human lineage."
About 2 million years ago, early stone tool-making humans, known scientifically as Oldowan hominin, are believed to have gone through number of physiological changes and ecological adaptations that caused them to require more daily energy. Among the changes the early humans went through were increased brain and body size, more intense investment in their offspring and significant expansion of their home range, according to Baylor University.
But demonstrating how the early humans acquired the extra energy needed to sustain the changes is a topic of much scholarly debate.
The find will reportedly help researchers better understand the diet and food acquisition strategies of some of the earliest human ancestors in Africa, as well as contribute to a debate over whether early humans met their energy needs primarily by hunting or scavenging.
"Our study helps inform the 'hunting vs. scavenging' debate in Paleolithic archaeology. The record at KJS shows that it isn't a case of either/or for Oldowan hominins two million years ago. Rather hominins at KJS were clearly doing both," Ferraro said.
The study's findings were recently published in the journal PLOS One.