来源：《新科学家》
原文刊登日期：2021年1月7日
Dogs may have become domesticated because our ancestors had more meat than they could eat. During the ice age, hunter-gatherers may have shared any surplus with wolves, which became their pets.
狗被驯化可能是因为我们的祖先有太多的肉吃不完。在冰河时代，狩猎采集者可能会与狼分享剩余的食物，而狼成了他们的宠物。
The timing and causes of the domestication of dogs are both uncertain. Genetic evidence suggests that dogs split from their wolf ancestors between 27,000 and 40,000 years ago. The oldest known dog burial is from 14,200 years ago, suggesting dogs were firmly installed as pets by then.
狗被驯化的时间和原因都不确定。基因证据表明，狗在2.7万到4万年前从狼的祖先中分离出来。已知的最古老的狗葬是在14200年前，这表明当时狗已经被固定为宠物了。
But it isn’t clear whether domestication happened in Europe or Asia – or in multiple locations – or why it happened. Dogs are the only animals domesticated by hunter-gatherers: all the others were domesticated after farming became widespread. One suggestion is that people domesticated dogs to help them with hunting, while another scenario has wolves scavenging human waste dumps and becoming accustomed to people.
但目前还不清楚驯化是发生在欧洲还是亚洲，或者在多个地方，以及为什么会发生。狗是唯一一种由狩猎采集者驯养的动物：所有其他的动物都是在农业普及后驯养的。一种说法是，人们驯养狗是为了帮助他们狩猎，而另一种说法是，狼在人类的垃圾堆中觅食，并对见到人类习以为常。
Maria Lahtinen of the Finnish Food Authority in Helsinki and her colleagues suggest that the key may have been an excess of meat.
赫尔辛基芬兰食品管理局的玛丽亚·拉赫蒂宁和她的同事认为，关键可能是肉类过量。
Dogs were domesticated when ice sheets covered much of northern Eurasia and the climate was colder than today. During this time, humans and wolves would have competed for food, as both are top predators.
狗是在冰原覆盖欧亚大陆北部的时候被驯化的，当时的气候比现在要冷。按理说，在这段时间里，人类和狼会争夺食物，因为它们都是顶级掠食者。
However, wolves can survive on nothing but lean meat – which contains protein and little else – for months. In contrast, humans cannot. There are limits to how much protein our bodies can handle, so we have to eat other food groups such as fat as well. “We are not fully adapted to eat meat,” says Lahtinen.
然而，狼仅靠瘦肉就能存活好几个月，而瘦肉只含有蛋白质和少量其他物质。相反，人类不能。我们的身体所能处理的蛋白质是有限的，所以我们还得吃其他种类的食物，比如脂肪。“我们还没有完全适应吃肉，”拉赫蒂宁说。
Her team calculated how much food was available during the Arctic winters, based on the prey species living there. They found there was an excess of lean meat, suggesting human hunters would have ended up with more of this than they could consume. Wolves could have eaten this surplus, implying the two species weren’t in competition during the harsh winters. Instead, humans could have shared lean meat with wolves without losing out themselves.
她的研究小组根据生活在北极的猎物种类，计算出北极冬季的食物供应量。他们发现那里有过量的瘦肉，这表明人类猎人最终会有更多的瘦肉，超过他们的食用量。狼可能会吃掉这些多余的食物，这意味着这两个物种在严酷的冬天没有竞争。相反，人类可以与狼分享瘦肉，而不会对自己造成什么损失。
Lahtinen suggests that hunter-gatherers may have taken in orphaned wolf pups – perhaps viewing them a bit like pets – and fed them on spare lean meat. They probably didn’t have any long-term goal in mind, but the tamed wolves would have later proved to be useful hunting partners – reinforcing the domestication. “They must have been very attractive for hunter-gatherers to keep,” says Lahtinen.
拉赫蒂宁认为，狩猎采集者可能收养了孤儿狼崽——也许把它们当成了宠物——用多余的瘦肉喂养它们。他们可能没有任何长期的目标，但被驯服的狼后来被证明是有用的狩猎伙伴——这反过来加强了驯化。拉赫蒂宁说：“它们对狩猎采集者来说一定非常有吸引力。”