取物的意愿可能是狼祖先种群中存在的狼的特征

取物的意愿可能是狼祖先种群中存在的狼的特征

Some wolf puppies are unexpectedly willing to play fetch, according to scientists who saw young wolves retrieve a ball thrown by a stranger and bring it back at that person's urging.

据科学家称，一些狼出人意料地愿意玩接球游戏，他们看到小狼群捡到一个陌生人扔的球，然后在那个人的催促下把球带回来。

This behavior wouldn't be surprising in a dog. But wolves are thought to be less responsive to human cues because they haven't gone through thousands of years of domestication.

这种行为在狗身上并不奇怪。但是狼被认为对人类的暗示反应较慢，因为它们没有经过数千年的驯化。

Exactly how dogs emerged from a now-extinct population of ancient wolves is a mystery. Wolves are large, dangerous carnivores, and yet they were the first animals that humans tamed. More than 15.000 years ago, when humans were still hunter-gatherers, this large predator somehow began cozying up to people, eventually becoming their "best friend."

狗是如何从现已灭绝的古狼种群中进化而来的，这是个谜。狼是大型、危险的食肉动物，但它们是人类最早驯化的动物。15000多年前，当人类还是采集狩猎人的时候，这种大型食肉动物不知怎么地开始与人类亲近，最终成为他们“最好的朋友”。

To try to get clues about how that happened, scientists such as Christina Hansen Wheat of Stockholm University in Sweden have been studying the differences between dogs and modern wolves. As part of her work, she raised litters of wolf puppies, feeding them and acclimating them to her presence but not playing with them or training them.

为了弄清楚这是如何发生的，瑞典斯德哥尔摩大学的克里斯蒂娜·汉森·麦特等科学家一直在研究狗和现代狼的区别。作为工作的一部分，她饲养了一窝小狼崽，喂养它们，让它们适应她的存在，但不与它们玩耍或训练它们。

At the age of 8 weeks, the wolf pups were put through a series of standard behavior tests that were administered by a person the wolves had never met.

在8周大的时候，狼崽们接受了一系列的标准行为测试，这些测试是由狼从没见过的人进行的。

This set of tests is normally used by dog breeders, says Hansen Wheat, to assess how their puppies act in social situations. "The fetching test just happened to be part of this test.

汉森·麦特说，这组测试通常被狗狗饲养者用来评估幼犬在社交场合的表现。“抓取测试只是这个测试的一部分。

It wasn't something we were targeting at all," she says. The person conducting the test threw a tennis ball and urged the wolf puppy to bring it back. Two litters of puppies utterly failed to do this, surprising the scientists not at all.

这根本不是我们的目标，”她说。进行测试的人扔了一个网球，并催促小狼把它带回来。两窝小狼完全没有做到这一点，这让科学家们一点也不惊讶。

"There's some hypotheses out there that the ability to understand human social cues is a unique dog trait, a trait that arose after domestication had been initiated," Hansen Wheat explains, so fetching on command is not a behavior expected in wolves.

“有一些假说认为，理解人类社会暗示的能力是狗的一种独有特征，这种特征是在驯化开始后产生的，”汉森·麦特解释说，因此，在狼中，按指令取物并不是一种预期的行为。

But then a third litter went through the tests. And as she watched through a window, one of the wolf puppies went for the ball and returned it to the tester, according to a report in the journal iScience.

但是第三窝小狼通过了测试。据《科学》杂志上的一篇报道称，当她透过窗户观看时，一只小狼崽扑向球，并把球还给了测试者。

"When I saw the first puppy fetch — I still get goosebumps when I talk about this — it was such a surprise," Hansen Wheat says. "It wasn't just one puppy, it was actually three of them. That was very exciting."

汉森·麦特说:“当我看到第一只小狼叼走的时候——说到这里我还是会起鸡皮疙瘩——这真是个惊喜。”“它不只是一只小狼，实际上是三只。这非常令人兴奋。”

Because three of the 13 tested wolf puppies spontaneously did this, a willingness to fetch might not be a dog trait, she says. Instead, it might be a wolf trait that existed in the ancestral wolf populations.

她说，因为13只接受测试的小狼崽中有3只是自发地这样做的，所以取物的意愿可能不是狗的特征。相反，这可能是存在于狼祖先种群中的狼的特征。

"It might have been something that we have tried to select upon during early domestication," Hansen Wheat says. "Wolf puppies doing this during early stages of domestication might have had a selective advantage, if they managed to establish a connection to our forefathers."

“这可能是我们在早期驯化过程中试图选择的东西，”Hansen Wheat说。“如果它们能与我们的祖先建立联系的话，小狼崽在驯化的早期阶段这样做可能有选择性优势。”

She notes that researchers who work with wolves typically have few animals to test. That means scientists simply might not have enough wolves to detect rare traits, making it hard to see variations as they attempt to compare wolves with dogs.

她指出，研究狼的研究人员通常没有什么动物可以测试。这意味着，科学家们可能没有足够的狼来发现罕见的特征，这使得他们在试图比较狼和狗时很难发现变异。