科学家让狗成为我们最好的朋友

This is Scientific American's 60-second Science, I'm Susanne Bard.

这里是科学美国人——60秒科学系列，我是苏珊娜·巴德。

All domestic dogs belong to a single species that descended from wolves—despite vast differences in size, appearance, behavior and temperament among breeds.

所有的家犬都属于同一个物种，都是狼的后裔，尽管不同品种之间在体型、外表、行为和性情上存在巨大差异。

While dogs first became domesticated tens of thousands of years ago, the breeds we know today are largely the result of selection for certain traits by humans over the past several hundred years.

虽然狗最早是在数万年前被驯化的，但我们今天所知道的品种在很大程度上是人类在过去几百年里对某些特征进行选择的结果。

“We have an enormous amount of diversity within the same species, and we can rarely observe such diversity in nature. So it’s a wonderful system to understand how evolution works within a short period of time.”

“我们在同一物种中有巨大的多样性，我们很少能在自然界中观察到这种多样性。因此，在短时间内了解进化是如何工作的，是一个非常棒的系统。”

Evolutionary biologist László Garamszegi of the Institute of Ecology and Botany in Hungary. He says that our playing with dogs is a key component of the human-canine bond.

匈牙利生态和植物研究所的进化生物学家拉斯洛·加拉姆塞吉说。他说，我们和狗玩耍是人犬关系的一个重要组成部分。

But breeds vary in their degree of playfulness. For example, a breed called the Vizsla is very playful.

但是品种的好玩程度各不相同。例如，一种叫做维兹拉的品种非常好玩。

“On the other hand, the Chihuahua doesn’t like to play at all. Of course, you can train a little bit, but the average level of playfulness will be always lower than in the Hungarian Vizsla.”

“另一方面，吉娃娃根本不喜欢玩。当然，你可以稍微训练一下，但平均的玩耍水平总是低于匈牙利的维兹拉。”

Garamszegi and his colleagues analyzed the playfulness of more than 89,000 purebred dogs across 132 breeds, from Pomeranians to Great Danes.

加拉姆塞吉和他的同事分析了 132 个品种的 89,000 多只纯种狗的好玩性，从博美犬到大丹犬。

The dogs were all given a test measuring their degree of enthusiasm for a game of tug-of-war with people.

这些狗都接受了一项测试，以衡量它们对与人进行拔河比赛的热情程度。

“We were interested in whether breeds could be distinguished by their average level of playfulness and what are the evolutionary forces that makes different breeds behave differently.”

“我们感兴趣的是，这些品种是否可以通过它们的平均玩耍水平来区分，以及是什么进化力量使不同品种的行为不同。”

The researchers found that after controlling for the degree of genetic relatedness between breeds, dogs bred for herding and sporting were more playful on average than dogs that had been selected for other purposes like the nonsporting and toy breeds.

研究人员发现，在控制了不同品种之间的遗传关联度后，平均而言，用于放牧和运动的狗比用于非运动和玩具等其他目的的狗更爱玩。

“For some functions, like hunting or herding, you need trainable dogs and the very strong owner-dog relationship. So if you have a playful dog, it’s easy to train. One way to train a dog is to play with the dog.”

“对于某些功能，比如打猎或放牧，你需要训练有素的狗，以及非常牢固的主人与狗的关系。所以如果你有一只爱玩的狗，训练它很容易。训练狗的方法之一就是和狗一起玩。”

By tracing playfulness back genetically through canine evolution, the researchers showed that the ancestors of today’s dogs already possessed an intermediate level of playfulness.

通过从基因上追溯狗的进化过程，研究人员发现，今天狗的祖先已经具备了中等程度的爱玩性。

“So this was one of the traits that was also important during the process of domestication.”

“所以这是在驯化过程中也很重要的特征之一。”

Selective breeding often amplified the trait.

选择性育种通常会放大这种特征。

“But some breeds, like the toy dogs, they actually lost some of this playfulness.”

“但有些品种，比如玩具狗，它们实际上失去了一些这种俏皮感。”

Toy breeds were originally meant to be fashion accessories for the aristocracy, so playfulness could be a liability.

玩具品种原本是贵族的时尚配饰，所以好玩可能是一种负担。

“They need to match with your clothes; they need to match with your traveling habits. But they do not need too much attention. And in this particular situation, if you have a playful dog, it just creates a problem for you.”

“它们需要与你的衣服搭配；它们需要与您的旅行习惯相匹配。但他们不需要太多关注。在这种特殊情况下，如果你有一只顽皮的狗，它只会给你带来问题。”

The study is in the journal Biology Letters.

该研究发表在《生物学快报》杂志上。

The research could help people choose the optimal pet for their family. But ultimately ...

该研究可以帮助人们为家人选择最佳宠物。但最终...

“If you want to train your dog, you have to play a lot with your dog.”

“如果你想训练你的狗，你必须经常和你的狗玩。”

Thanks for listening for Scientific American's 60-second Science. I'm Susanne Bard.

谢谢大家收听科学美国人——60秒科学。我是苏珊娜·巴德。