Around 2 million years ago early stone tool-making humans known as Oldowan hominin started to exhibit a number of physiological and ecological adaptations -- an increase in brain and body size, heavier investment in their offspring and significant home-range expansion -- that required greater daily energy expenditures, and there has been debate about how those early humans acquired that extra energy.
A wealth of archaeological evidence from a site in Kenya known as Kanjera South, or KJS, including animal bones and rudimentary stone tools, suggests they met their new energy requirements through an increased reliance on meat eating, Baylor University anthropologist Joseph Ferraro said.
"Considered in total, this study provides important early archaeological evidence for meat eating, hunting and scavenging behaviors -- cornerstone adaptations that likely facilitated brain expansion in human evolution, movement of hominins out of Africa and into Eurasia, as well as important shifts in our social behavior, anatomy and physiology," he said.
The evidence -- cut marks on bones that show evidence of systematic butchering -- shows hominins acquired an abundance of nutritious animal remains through a combination of both hunting and scavenging behaviors, Ferraro said in a Baylor release Monday.
"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 2 million years ago," he said. "Rather hominins at KJS were clearly doing both."