Wild elephants are one of the few known species to show signs of self-domestication. The phenomenon has only previously been documented in humans and bonobos, a closely related primate.

野生大象是少数有自我驯化迹象的已知物种之一。这种现象以前只在人类和倭黑猩猩（一种近亲灵长类动物）身上有过记录。

Humans have bred animals to maximise traits such as friendliness, sociability and a docile temperament in a process called domestication. Some researchers believe humans and bonobos have gone through a similar process but that they have naturally done it to themselves.

人类在驯化过程中，最大限度地培育动物友好、社交和温顺的气质等特征。一些研究人员认为，人类和倭黑猩猩也经历过类似的过程，但它们是自然而然地对自己进行了驯化。

Limor Raviv at the Max Planck Institute for Psycholinguistics in the Netherlands wondered if other species have self-domesticated too. She decided to start with African savannah elephants （Loxodonta africana）， a species with which she was already familiar. She and her colleagues looked at how the elephants compared with bonobos （Pan paniscus） and humans on 20 different measures.

荷兰马克斯·普朗克心理语言学研究所的利莫尔·拉维夫，想知道其他物种是否也有自我驯化的能力。她决定从她已经熟悉的非洲大草原象（Loxodonta africana）开始。她和同事们用20种不同的方法，将大象与倭黑猩猩（Pan paniscus）和人类进行比较。

They found that all three species display similar behaviours and share certain physical features. Like bonobos and humans, elephants are social, play, have a long childhood and care for the offspring of others in their group. Wild African elephants’ also share a shortened jawbone – a trait shared by many domesticated animals – and show restraint in aggression toward others.

研究发现，这三个物种表现出相似的行为，并具有某些相同的身体特征。像倭黑猩猩和人类一样，大象是社会性的，喜欢玩耍，有漫长的童年，并照顾群体中其他大象的后代。野生非洲象也都有较短的下颚骨——这是许多家养动物共有的特征——并且在攻击他人时表现出克制。

Next, the researchers looked for commonalities between the genome of domesticated animals and the genome of wild elephants. By drawing on studies of 261 mammals such as cattle, dogs, cats and horses, they built a list of genes frequently associated with domestication. They then identified 674 genes as having a high likelihood of being passed down from earlier elephant generations.

接下来，研究人员寻找驯养动物基因组和野生大象基因组之间的共同点。通过对牛、狗、猫和马等261种哺乳动物的研究，他们建立了一份与驯化有关的基因列表。然后，他们确定了674个基因，这些基因极有可能是从早期大象世代中遗传下来的。

The team found that 79 of those African elephant genes were associated with domestication in other species, further strengthening the idea that elephants evolved these traits without the direct intervention of people. This is significant, says Raviv, because elephants and humans are not closely related, suggesting domestication can evolve convergently in multiple branches of the mammal evolutionary tree.

研究小组发现，这些非洲象的基因中有79个与其他物种的驯化有关，进一步强化了大象在没有人类直接干预的情况下进化出这些特征的观点。拉维夫说，这很重要，因为大象和人类关系并不密切，这表明驯化可以在哺乳动物进化树的多个分支中趋同进化。

Raviv suspects Asian elephants （Elephas maximus） may also show signs of self-domestication, but genome data was only available for African elephants at the time of the research. She says it is possible that other highly intelligent, social animals like dolphins, whales and parrots have also evolved self-domestication

拉维夫认为亚洲象也可能表现出自我驯化的迹象，但在研究期间，只有非洲象的基因组数据可用。她说，其他高智商的群居动物，如海豚、鲸鱼和鹦鹉，也有可能进化出自我驯化的能力。