狗的基因源头：狗复杂的基因
Ancient Dogs Had Complex Genetic Histories
古代狗有复杂的遗传历史
Dogs were the first animals to be domesticated. And they stuck with us as we changed lifestyles from hunting/gathering to farming to city living.
狗是最早被驯养的动物。当我们的生活方式从狩猎/采集到农耕再到城市生活的时候，他们和我们在一起。
“The dog is a species that is intimately linked to human history.”
"狗是一个与人类历史密切相关的物种。"
Anders Bergström, a postdoc at the Francis Crick Institute in London. He and his colleagues studied the genomes of 27 ancient dog bones dug up around the world. They found that by 11,000 years ago:
伦敦Francis Crick研究所的博士后Anders Bergström说。他和他的同事们研究了在世界各地挖掘出的27块古代狗骨头的基因组。他们发现这些是在11000年前的骨头。
Bergström: “We see that the dog started to diversify genetically. So we find evidence of at least five major lineages of dogs already at this time.”
Bergström说道，我们看到狗的基因开始多样化。所以我们发现了至少五种狗的主要血统的证据。
Dog remains have been found in Europe, Asia and the Americas in a pattern similar to how humans moved and mixed.
在欧洲、亚洲和美洲都发现了狗的遗骸，它们的迁徙和混合方式与人类相似。
Bergström: “To a large degree the history of dogs seems to have been shaped by human history, so likely reflecting how when humans moved they would have brought their dogs with them.”
Bergström说道，在很大程度上，狗的历史似乎是由人类历史塑造的，这很可能反映了当人类搬家时，他们会带着狗一起走。
Ancient humans clearly found dogs to be very useful.
远古人类显然发现狗非常有用。
Bergström: “In the Arctic there's evidence that sled dogs actually emerged very early and people used them for the particular purpose of sledding, perhaps as early as 10,000 years ago.”
Bergström说道，在北极，有证据表明雪橇犬很早就出现了，人们用它们来拉雪橇，也许早在一万年前。
A few modern breeds—like the African Basenji, New Guinea Singing Dog or Australian Dingo—are similar to one of the five ancient lineages. Most other modern breeds derive at least in part from European dogs, which came to dominate dog genomes.
少数现代品种，如非洲巴桑吉犬、新几内亚唱歌犬或澳大利亚野狗，与五种古老血统中的一种相似。大多数其他现代品种至少有一部分来自欧洲狗，欧洲狗在狗的基因组中占主导地位。
Bergström: “If you go back four or five thousand years ago there's a great diversity of dogs in Europe, but at some point there was probably a single population that expanded and basically replaced other populations in Europe. This was something that we did not predict, and you couldn't really see just from studying archaeology. But when we look at the DNA we see that there's all this diversity in the past that is not represented in present day dogs.”
Bergström说道，如果你回到四五千年前，在欧洲，狗的种类非常多样，但在某个时间点，可能有一个单一的种群扩张，基本上取代了欧洲的其他种群。这是我们没有预料到的，你也不能仅仅通过研究考古学来发现。但是当我们观察DNA的时候，我们会发现在过去所有这些多样性在现在的狗身上都没有体现出来。
The study is in the journal Science, where you’ll find maps of dog migrations over time.
这项研究发表在《科学》杂志上，你会发现狗随时间迁移的地图。
One odd finding: about 11,000 years ago it looks like dogs spread more widely than humans did.
一个奇怪的发现是:大约11000年前，狗的传播似乎比人类更广泛。
Bergström: “That's actually a process we don't really understand. So how could the dog spread so quickly and widely? We're not aware of any human migrations at this time that could have facilitated the spread of the dog but somehow it spreads very quickly to human groups all across the world, perhaps because it was a very useful thing for these early human hunter-gatherer groups.”
Bergström说道，这实际上是一个我们并不真正了解的过程。那么，狗是如何传播得如此迅速和广泛的呢?我们还没有发现在这个时期有任何人类迁徙能够促进狗的传播，但是不知怎么的，狗传播得很快，在全世界的人类群体中，也许是因为它对这些早期的人类狩猎采集群体非常有用。
Humans were also useful to dogs. Prehistoric Petcos didn’t exist, so dogs probably ate what humans did. And as humans started to farm, both species quickly adapted to digest more grains. The number of copies of a starch-digesting gene in both humans and dogs increased in the generations following the invention of agriculture.
人类对狗也很有用。史前的Petcos还不存在，所以狗可能吃人类吃的东西。随着人类开始农耕，这两个物种都迅速适应了消化更多谷物。在农业发明之后，人类和狗体内淀粉消化基因的拷贝数都在不断增加。
Bergström: “Yeah, so that's a very striking example of convergent evolution between humans and dogs…in a way it's kind of interesting to think of the dog as a kind of an evolutionary experiment that runs alongside human history and undergoes the same lifestyle changes that we do.”
Bergström说道，是的，所以这是人类和狗之间趋同进化的一个非常显著的例子。在某种程度上，把狗看作是人类历史上的一种进化实验是很有趣的，它经历了和我们一样的生活方式变化。