The gray wolf.

這個動物，就是灰狼。

Over time, the wolves changed in body and temperament.

隨著時代演變，狼逐漸改變他的體型和性格。

Their skulls, teeth and paws shrank.

他們的頭骨縮小、牙齒和爪子縮短。

Their ears flopped.

耳朵垂下來。

They gained a docile disposition, becoming both less frightening and less fearful.

牠們變得溫馴，變得比較不讓人驚嚇和害怕。

They turned into dogs.

牠們最終演化成狗。

Scientists agree that all dogs descend from wild ancestral wolves, but they disagree as to when, where and how that happened.

科學家們有共識狗是從野狼的祖先演化而成 ，但他們對於是何時、何地、如何發生的看法分歧。

Gregor Larson from the University of Oxford has been trying to get some firm answers.

牛津大學的 Gregor Larson 試著找出更肯定的解答。

Already, he and his team have yielded a surprising discovery.

如今，他和團隊成員有了令人訝異的發現。

They think dogs were domesticated not once but twice.

他們認為狗不只被馴化過一次，而是兩次。

So here's the full story as Larson sees it.

現在，我們來聽聽 Larson 完整的研究。

Many thousands of years ago, somewhere in western Eurasia, humans domesticated grey wolves.

數千年前，在歐亞大陸西部的某處，人類馴養灰狼。

And the same thing happened independently far away in the East.

同時，遠在東邊，也發生著一樣的事。

Around the Bronze Age, some of the ancient eastern dogs migrated west alongside their human partners.

在青銅時代，有些古代東方的狗與牠們的人類夥伴一同遷徙到西方。

And along their travels, these migrants encountered the indigenous, ancient western dogs.

而在他們的旅途中，這些移民者與古代西方當地的狗相遇。

They mated with them, doggy style presumably, and effectively replaced them.

牠們用狗兒專屬的方式交配，並成功取代西方當地的狗。

So today's western dogs trace most of their ancestry to the ancient eastern migrants.

因此，現今西方狗的祖先大部分都是古代東方遷徙而來的狗。

Less than 10 percent comes from those ancient western dogs, which have since gone extinct.

不到 10% 的狗是來自古代的西方狗，而且牠們現在也絕種了。

Other dog genetics experts think that there are other possible explanations.

狗遺傳學專家認為還有其他的可能。

But Larson adds that his gene-focused peers are ignoring one crucial line of evidence--bones.

但 Larson 補充，她研究基因的同伴忽略了「骨骼」這項關鍵證據。

If dogs originated just once, there should be a neat gradient of fossils with the oldest ones at the center of domestication and the youngest ones far away from it.

如果狗指起源於一個地方，那化石應該會是整齊的，例如，最古老化石會在馴養中心點，而越年輕的越向外延伸。

But that's not what we have.

但這與事實不相符。

So we now have a new origin story for dogs.

所以，我們對於狗的起源有了新的故事。

And this matters because dogs were the first species that we domesticated.

這很重要，因為狗是人類馴養的第一種物種。

They came before crops, before livestock.

比農作物和牲畜更早。

They heralded a change in our relationship to the natural world.

牠們揭示了我們與大自然的連結。