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Modern-day humans eat a lot of meat. Some nutritionists say perhaps too much. But fossils in Tanzania indicate that early humans considered meat a dietary staple much earlier than first thought. What’s more, meat may have played a major role in evolution.

At least one and a half million years ago, humans considered meat a main dish, not just occasional fare. That’s very big news to archeologists. The evidence is found in skull fossil fragments of a young child discovered in Tanzania’s Olduvai Gorge. What evidence is that? We’ll find out after we consider the mystery of meat.

Professor Manuel Dominguez-Rodrigo of Madrid’s Complutense University has been searching for clues about early humans for 20 years. He’s been digging around the gorge since 2006, after analyzing fossils found by the famous British archeologist and anthropologist Mary Leakey.

“There was an increasing amount of evidence that early humans pretty much around two million years ago were eating meat. And archeologists over the past 50 years have been debating two main questions. One, was meat an important element in the diet of these hominids or was it just a complimentary element like you might see in modern chimpanzees, for instance? And question number two is --whether it was important or not – how did they acquire this meat. Did they hunt the animals they were eating? Did they scavenge the animals they were eating?”

Archeologists know from sites in Ethiopia that human ancestors ate meat as far back at two-point-six million years ago. But there are so few bone fragments from that time with primitive knife marks on them that it’s unclear how often meat was consumed.

Now, they can confirm that it was indeed a regular staple of the diet at least one-and-a-half million years ago. Dominguez-Rodrigo says it tells a lot about the social habits of early humans and much more.

“Getting meat in a Savannah ecosystem, in a Savannah environment, is not something simple for a primate. It is something that requires planning. Something that requires cooperation. Something that requires a complex social organization. We were not sure how these early humans behaved in that regard. It is important because this is happening pretty much at the same time period as we see that the brain starts developing, starts growing, compared to previous hominids. And brain growth has important nutritional requirements and some of them are the vitamins that are associated with meat eating,” said Dominguez-Rodrigo.

He’s talking about B vitamins and that’s where the skull fragments come in. Scientists know from studying the remains of humans over the centuries that dietary deficiencies leave traces in bone. The fragments belonging to a one or two year old child had bone lesions commonly associated with a lack of B vitamins. In other words, the lesions indicate the child was anemic from not eating enough meat.

“We don’t find these pathologies commonly in populations that live on hunting and gathering, because the diet of hunter / gatherers is actually more beneficial for human metabolism than the diet of producers. So our surprise was to find that this pathology typical of sedentary populations actually was found in a prehistoric hunter-gatherer individual that was 1.5-million years old,” he said.

Dominguez-Rodrigo realizes the findings will not make vegetarians very happy.

“I’m fully aware of that, yes, (laughs). We find vitamins, we find folic acid, we find vitamin B-12 now everywhere in the cereals that we eat in the morning and in many other foods that we take because a lot of that has been artificially produced. But in nature, if we were living on whatever we’re able to obtain by living in a Savannah in Africa B-12 can only be obtained in meat,” he said.

The archeologist describes meat as “a crucial element in becoming human.”

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（来源：VOA 编辑：Julie）