A few of our species’ earliest ancestors might have spent much more time consuming salad than steak.
An evaluation of the chemical composition of fossilized enamel in Australopithecus africanus — an early relative of people — suggests the bipedal primates had primarily vegetarian diets, researchers report within the Jan. 17 Science. The findings present direct proof of the place considered one of humanity’s earliest ancestors sat in its native meals net over 3 million years in the past.
Weight loss program has been a vital element of human evolution, says Tina Lüdecke, a geochemist on the Max Planck Institute for Chemistry in Mainz, Germany. A swap from a vegetarian weight loss plan to the routine consumption of high-protein meals like meat is hypothesized to have fueled the evolution of people’ cognitive superpowers.
“These high-quality meals present us with a variety of vitality, which we have to energy our big brains,” Lüdecke says.
The exact timing of that gastronomic shift is unclear. To get a greater take a look at diets within the deep previous, Lüdecke and her colleagues drilled samples out of the enamel of 43 roughly 3.5-million-year-old fossilized mammals from the Sterkfontein caves in South Africa, together with seven totally different A. africanus people. Locked within the matrix of tooth enamel are tiny bits of nitrogen-bearing natural materials, which reveal secrets and techniques about historic diets, because the ratio of two types of nitrogen is linked to the relative quantity of meat eaten in life.
Based mostly on comparisons of the enamel nitrogen ratios from A. africanus with these of different extinct mammals from Sterkfontein and trendy African mammals, the early people seem to have had a variable weight loss plan, however not one wealthy in mammalian meat. The findings might have implications for the way researchers perceive meat consumption’s affect within the emergence of different human traits. As an example, variations in Australopithecus akin to shorter snouts, bipedalism and the flexibility to thrive in a savanna ecosystem might have predated the transfer to a brain-boosting meat-rich weight loss plan.
Lüdecke notes that the findings don’t imply A. africanus couldn’t have sometimes exploited a meaty meal. The outcomes additionally don’t rule out the primates consuming a number of termites — a dependable, high-energy meals — since they include comparatively much less of the type of nitrogen elevated in mammalian meat. “We see that apes these days [fish for termites], so why not our ancestors?”
Now that there’s baseline information, Lüdecke says future research may use the identical strategies on the enamel of different, later human species to see how diets might have modified over hundreds of thousands of years.
