There's an ongoing debate among today's humans about whether eating meat is ethically and/or environmentally right or not. A debate that would've made our stone-age ancestors crack up.
A new study from Tel Aviv University reconstructed the nutrition of stone-age humans to analyze whether they were specialized carnivores or generalist omnivores. The results show that humans were apex predators for about two million years, only switching to feeding on vegetables after animals started becoming extinct towards the end of the stone age.
This led them to become farmers, domesticating both plants and animals.
"So far, attempts to reconstruct the diet of stone-age humans were mostly based on comparisons to 20th-century hunter-gatherer societies," explained Dr. Miki Ben-Dor.
"This comparison is futile, however, because two million years ago hunter-gatherer societies could hunt and consume elephants and other large animals -- while today's hunter-gatherers do not have access to such bounty. The entire ecosystem has changed, and conditions cannot be compared."
He also added that "We decided to use other methods to reconstruct the diet of stone-age humans: to examine the memory preserved in our own bodies, our metabolism, genetics, and physical build. Human behavior changes rapidly, but evolution is slow. The body remembers."
To come to this conclusion, Dr. Ben-Dor and his colleagues collected about 25 lines of evidence from about 400 scientific papers from different scientific disciplines. The team used evidence from human biology supplemented by archaeological facts. They eventually came to the conclusion that humans specialized in hunting large animals and were in fact hypercarnivores that contributed to the extinction of large animals.
"Hunting large animals is not an afternoon hobby," Dr. Ben-Dor added. "It requires a great deal of knowledge, and lions and hyenas attain these abilities after long years of learning. Clearly, the remains of large animals found in countless archaeological sites are the result of humans' high expertise as hunters of large animals. Many researchers who study the extinction of the large animals agree that hunting by humans played a major role in this extinction -- and there is no better proof of humans' specialization in hunting large animals."
The study was published in the American Journal of Physical Anthropology.