A new study has, for the first time, used zinc isotope analysis to determine the position of Neanderthals, — our extinct relatives — in the food chain. The findings suggest that the species were in fact carnivores.
The science and other stuff to know
Scientists know a substantial amount about the Neanderthals, including their genetic makeup and lifestyle. But one thing has left researchers divided: The Neanderthal diet. While several studies have shown that the species consumed plenty of plants, other research suggests that they eat nothing but meat.
In an attempt to resolve this species’ diet mystery, an international team of researchers led by Klevia Jaouen, of the French National Centre for Scientific Research (CNRS), devised a new technique to understand what Neanderthals actually ate. By analyzing the zinc isotope ratios present in a Neanderthal fossilized tooth found at the Gabasa site cave in Spain, they found that this species consumed a strictly carnivorous diet. The findings of the study have been published in the journal PNAS.
The team also compared bones of other animals from the same period and geographical area, including carnivores such as lynxes and wolves and herbivores like rabbits and chamois. They concluded that Neanderthals were probably carnivores who didn’t consume the blood of their prey.
Other chemical evidence suggests the individual was weaned before two-and-a-half years of age. They also likely died in the same area where they were born, the study adds.
The team couldn’t document any plant consumption based on the zinc-isotope analysis. “But if they ate fruits from time to time, we could not detect it because fruits do not contain a lot of zinc,” Jaouen explained.
This is the first time this method has been used to attempt to identify a Neanderthal’s diet. As per the new technique, the lower the proportions of zinc isotopes in the bones, the more likely they are to belong to a carnivore. And the tooth enamel of the Neanderthal in the study had a low concentration of these compositions. This suggests the species ate muscle and liver from deer and rabbits.
Up until now, scientists had to extract proteins and analyze the nitrogen isotopes present in the bone collagen when determining species’ diet. However, this method can only be used in temperate environments, and rarely on samples over 50,000 years old. When these conditions aren’t met, nitrogen isotope analysis is very complex, or even impossible. But with this new zinc isotope analysis technique, it’s now easier for scientists to distinguish between omnivores and carnivores.
While these findings support existing evidence of Neanderthals’ carnivorous tendencies, more research is still needed. The team hopes to use the new technique on other Neanderthal specimens in the future to understand the full range of Neanderthal diets.