Homo sapiens have given neanderthals have a bad rap. The problem probably started with when we turned it into an insult; indeed, "neanderthal" is often used to refer to someone who is stupid and/or brutish, an unfair reputation to attach to a real-life human subspecies that roamed Eurasia for hundreds of thousands of years before mysteriously vanishing roughly 40,000 years ago. (Technically, because neanderthals mated extensively with humans, they're not completely vanished from the genomic record: those of us with European or Asian heritage have DNA that is one to two percent neanderthal.)
Fortunately for their public image, modern scientists are continuing to learn new facts about neanderthals that are complicating the prevailing narrative. A 2018 study revealed that neanderthals practiced community health care, while that same year a group of experts concluded that the famous artwork Panel of the Lions in France's Chauvet Cave was likely painted by neanderthals.
Now a new study in the journal PNAS has used state-of-the-art technology to break down the complexities of the neanderthals' diet — and cast doubt on one popular theory about why they went extinct.
Neanderthal teeth are the key ingredient in this story. By measuring zinc isotope ratios in the tooth enamel of a neanderthal found at a site in the Spanish hamlet of Gabasa, an international team of scientists could determine the likelihood that neanderthals in that region regularly ate meat. When they found a low proportion of zinc isotopes (most plants contain a lot of zinc), they concluded that this Neanderthal — and, by extension, others in its community — likely ate a lot of meat. As the authors explain, large herbivores usually have higher proportions of zinc isotope ratios in their bones than carnivores, and this neanderthal's scores were "substantially lower than that of the lowest carnivore's value." To have a basis for comparing the neanderthal's results, the study also examined other animals from the region, including carnivores like wolves and lynxes and herbivores like rabbits and chamois.
Some scholars speculate that the neanderthal diet may not have been able to adapt to changing environmental conditions.
Of course, this is just one neanderthal tooth, a fact that the authors readily acknowledge. Their next step will be to perform the same test on neanderthal remains at the Payre site in southeast France to see if doing so confirms their current results.
"It does not mean indeed that they were carnivores anywhere," Klervia Jaouen, PhD, the corresponding author of the study and a scientist at France's Géosciences Environnement Toulouse at the Observatoire Midi-Pyrénées, told Salon by email. Jaouen explained that what the studies proves for sure is that "as soon as we use a method based on isotope ratios (an approach that help having an idea of the proportion of meat and plant in the diet of an individual), we find that neanderthals are carnivores, anywhere, anytime." In addition, while previous studies of late neanderthals had used remains from France and the Netherlands, "here we have a probably older individual from Spain — where the plant consumption has been often debated."
The study's conclusions also raises provocative questions about why neanderthals went extinct. There are many theories including disease, climate change and assimilation into the main human genome, and some scholars speculate that the neanderthal diet may not have been able to adapt to changing environmental conditions.
While other studies had also indicated that neanderthals ate a lot of meat, none had utilized the zinc isotope method.
"Neandertals' diets are a topic of continued debate, especially since their disappearance has been frequently attributed to their subsistence strategy," the authors write. "There is no clear consensus on how variable their diets were in time and space."
While previous research on neanderthal diets had focused on nitrogen isotope analyses of collagen, there were a number of practical problems with basing conclusions off of nitrogen isotopes; among other things, those proteins are rarely preserved in samples after they reach a certain age. By successfully using zinc isotopes to measure meat consumption among neanderthals, the researchers hope they have pioneered a new method for addressing questions about neanderthal diets. While other studies had also indicated that neanderthals ate a lot of meat, none had utilized the zinc isotope method.
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Though pop culture depicts neanderthals as brutish, club-wielding, pelt-wearing fellows, it was not actually known if they were indeed hunters and therefore meat-eaters. That means that previous depictions of them, say, gnawing on a hunk of flesh from a mammoth, were based on speculation. This study, though not definitive, certainly clears up some of that speculation.
While pruud carnivores may rejoice in this news, Jaouen cautioned against over-simplifying the study's conclusion: Neanderthals may have preferred meat, but "as evidenced by dental calculus studies, neanderthals probably ate plants" as well.
"What we conclude in this study, is that the frequency of this consumption (for the individual that we analyzed) is low, or that the amount eaten is very low," Jaouen told Salon. "However, some plants have a very small zinc content like fleshy fruits. If a Neanderthal was eating one or two per day, we would probably not see it with this method. But the diet of the Neanderthal was mostly based on meat, in any case."
Even in human diets, meat consumption varies tremendously. Traditional diets of circumpolar indigenous groups, such as Inuit and Inupiaq peoples, thrived on a diet that was almost fully carnivorous; whereas the The Toda tribe of India's Nilgiri Hills has subsisted for generations on a strict vegetarian diet.
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