犬类拥有复杂的遗传进化史

This is Scientific American's 60-second Science, I'm Eliene Augenbraun.

这里是科学美国人——60秒科学系列，我是埃琳·奥根布朗。

Dogs were the first animals to be domesticated.

狗是最早被驯养的动物。

And they stuck with us as we changed lifestyles from hunting/gathering to farming to city living.

当我们的生活方式从狩猎/采集到农耕再到城市生活时，它们一直跟着我们。

“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 Bergstrom, a postdoc at the Francis Crick Institute in London.

安德斯·伯格斯特罗姆是伦敦弗朗西斯·克里克研究所的博士后。

He and his colleagues studied the genomes of 27 ancient dog bones dug up around the world.

他和他的同事研究了在世界各地挖掘的27块古代狗骨头的基因组。

They found that by 11,000 years ago ...

他们发现，在11000年前……

“We see that the dog started to diversify genetically.

“我们发现狗开始在基因上多样化。

So we find evidence of at least five major lineages of dogs already at this time.”

我们在这一时期已经发现了至少5种主要犬类谱系的证据。”

Dog remains have been found in Europe, Asia and the Americas in a pattern similar to how humans moved and mixed.

在欧洲、亚洲和美洲发现了狗的遗骸，其模式与人类的迁徙和融合方式相似。

“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.”

“在很大程度上，狗的历史似乎受到了人类历史的影响——这很可能反映了人类在移动时是如何带着他们的狗的。”

Ancient humans clearly found dogs to be very useful.

古人类显然发现狗非常有用。

“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.”

“在北极，有证据表明，雪橇狗实际上很早就出现了，人们可能早在1万年前就将它们用于滑雪橇的特殊目的。”

A few modern breeds—like the African basenji, New Guinea singing dog or Australian dingo—are similar to one of the five ancient lineages.

一些现代品种——如非洲巴仙吉犬、新几内亚歌唱犬或澳大利亚野犬——与五种犬类谱系之一相似。

Most other modern breeds derive at least in part from European dogs, which came to dominate dog genomes.

大多数现代犬类品种至少部分源自欧洲犬类，欧洲犬类在犬类基因组中占主导地位。

“If you go back 4,000 or 5,000 years ago, there’s a great diversity of dogs in Europe.

“如果你回到4000或5000年前，欧洲的犬类纷杂，具有多样性。

But at some point, there was probably a single population that expanded and basically replaced other populations in Europe.

但在某个时刻，可能只有一个种群在扩张，基本上取代了欧洲的其他种群。

This was something that we did not predict and you couldn’t really see just from studying archaeology.

这是我们没有预料到的，仅仅通过研究考古学是无法看到的。

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.”

但当我们观察DNA时，我们发现过去的所有这些多样性都没有在今天的狗身上体现出来。”

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，你可以在杂志上找到狗的迁徙地图。

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，狗的分布似乎比人类更广泛。

“That’s actually a process we don’t really understand.

“这实际上是一个我们并不真正了解的过程。

So how could the dog spread so quickly and widely?

那么，狗是如何传播得如此迅速和广泛的呢?

We’re not aware of any human migrations at this time that could have facilitated the spread of the dog.

目前我们还没有发现这个时期的任何人类迁徙可能会促进狗的扩张。

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.”

但狗以某种方式迅速扩张到世界各地的人类群落，可能是因为它对这些早期人类狩猎-采集群落非常有用。”

Humans were also useful to dogs.

人类对狗也很有用。

Prehistoric Petcos didn’t exist, so dogs probably ate what humans did.

史前的宠物狗并不存在，所以狗可能吃的和人类一样。

And as humans started to farm, both species quickly adapted to digest more grains.

随着人类开始农耕，这两个物种很快就适应了消化更多的谷物。

The number of copies of a starch-digesting gene in both humans and dogs increased in the generations following the invention of agriculture.

在农业发明后的几代中，人类和狗的淀粉消化基因拷贝数都在增加。

“Yeah, so that’s a very striking example of convergent evolution between humans and dogs.

“是的，这是人类和狗之间趋同进化的一个非常显著的例子。

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.”

在某种程度上，把狗看作是一种进化实验，它与人类历史相伴，经历着与我们一样的生活方式改变，这是一种有趣的想法。”

For Scientific American's 60-second Science. I'm Eliene Augenbraun.

感谢收听科学美国人——60秒科学。我是埃琳·奥根布朗。