That is what a new study written by James Cole of the University of Brighton in England says. Cole says compared to large animals, humans do not provide much food. His study was published in the journal Scientific Reports.
这是英国布莱顿大学詹姆斯·科尔（James Cole）撰写的一项新的研究。科尔表示，与大型动物相比，人类提供不了太多食物。他的这项研究发表在《科学报告》杂志上。

Cole studied nine places where fossils have been found and where researchers have found evidence of cannibalism. Such signs include cutting marks on the bones.
科尔研究了9处发现化石以及科研人员发现了同类相食证据的地方。这类迹象包括骨头上的切割痕迹。

Scientists dated the sites to between 14,000 and more than 900,000 years ago. That is the so-called Paleolithic period, also known as the Stone Age.
科学家确定这些遗址的年代是在1.4万年到90万年以前，也就是所谓的旧石器时代，也被称之为石器时代。

Five of the sites had Neanderthal fossils, the remains of earlier human ancestors. Two sites had fossils of prehistoric members of our own species and the others had fossils from much earlier human ancestors.
其中五处遗址有尼安德特人的化石，也就是人类早期祖先的遗骸。两处遗址有我们同物种史前人类成员的化石，其它遗址有更早人类祖先的化石。

Cole estimated how many calories each of the bodies at each site had. He used earlier studies that found eating an average-sized modern-day human could provide up to 144,000 calories. He then made his estimates, based on the ages of the bodies at the sites.
科尔估算了每处遗址的遗骸所拥有的卡路里。此前的研究发现食用中等身材的现代人类可以提供14.4万卡路里热量，他借用了这项研究的数据。然后他基于遗址遗骸的年龄做出了推算。

The researcher found that the hunters would not get as much energy from the humans as they would from one large animal -- like a mammoth, a woolly rhino or a bear. So, Cole asked, why would the early humans hunt and kill their own species?
研究人员发现，猎手们无法从人类中得到像猛犸象、长毛犀牛或熊这类大型动物中那么多的热量。因此科尔问道，早期人类为什么会猎杀同物种成员呢？

"You're dealing with an animal that is as smart as you are, as resourceful as you are, and can fight back in the way you fight them," Cole noted.
科尔说，“你面对的是跟你一样聪明、机敏的动物，他们会用你对抗他们的方式做出回击。”

He says our ancestors may have eaten members of their species who had died because they did not have to be hunted. But he says cannibalism probably took place for reasons other than the need for food. He said it could have happened after times of violence or to defend territory.
他说，我们的祖先可能吃过他们同物种中已经死去的成员，因为他们无需被猎杀。但是他表示，发生同类相食的原因可能不是为了食物。他说，这可能是经过暴力或捍卫领土事件之后发生的行为。

Tim White of the University of California, Berkeley and Paola Villa of the University of Colorado Museum in Boulder said they do not know any scientists who believe our ancestors hunted each other for food. In an email, Villa said the new study "does not change our general understanding of human cannibalism."
加州大学伯克利分校蒂姆·怀特（Tim White）和科罗拉多大学波尔得分校博物馆的波拉·维拉（Paola Villa）表示，他们不认识任何认为我们的祖先互相猎杀为食的科学家。维拉在一封邮件中表示，这项新研究“不会改变我们对人类同类相食的一般理解。”

But Palmira Saladie, of the Catalan Institute for Human Paleoecology and Social Evolution near Barcelona, Spain, said Cole's study "will undoubtedly be key in the interpretation of new sites and the reevaluation of old interpretations."
但是西班牙巴塞罗那市附近的加泰罗尼亚人类古生态和社会进化研究所的帕尔米拉·桑拉德（Palmira Saladie）表示，科尔的研究“无疑将是解释新遗址和重新评估旧的解释的关键。”

In an email, she wrote that, to understand why our ancestors sometimes ate each other, "we still have a long way to go."
她在一封邮件中写到，想要弄明白我们的祖先为什么有时候会相食，“我们还有很长的路要走。”