基因研究发现狗起源于中国

A new scientific research report has found strong evidence suggesting that man's best friend originated from China some 33,000 years ago.

一项最新的科学研究发现了有力证据，证明人类最好的朋友——狗，起源于大约3.3万年前的中国。

The study, the findings of which were published in the science journal Cell Research, found that Chinese indigenous dogs represent an intermediate form between wolves and breed dogs, and that they have not experienced intense artificial selection.

研究结果已发表在科学杂志《细胞研究》上。该研究称，中国本地狗是狼与狗的中间体，没有经历过激烈的人工选择。

"Analyses of Chinese indigenous dogs therefore allow us to stratify the domestication process in dogs, and investigate the role of positive selection that occurred specifically during the first stage of domestication," said the report.

报告称：“因此，对中国本地狗的分析让我们可以对狗的驯化过程进行分类，进而调查“正向选择”在驯化第一阶段发挥的具体作用”。

The researchers also found that the southern Chinese indigenous dogs together with several East Asian dogs, such as the Chow or Shar Pei, are closest to wolves.

研究人员还发现，中国南方的狗以及一些东亚的狗品种（如雄狮狗和沙皮狗）更接近狼。

The history of dog domestication is often depicted as a two-stage process where primitive dogs were first domesticated from their wild ancestors, the gray wolves. In the second stage, the primitive forms were further selected to form many dog breeds with specialized abilities.

狗的驯化历史可分为两个阶段，原始的狗最初由它们“野生的祖先（即灰狼）”驯化而来。在第二阶段，原始种类被进一步选择，形成了很多具有特殊能力的狗。

The researchers collected the genome sequences of 58 canids from across the world, including samples from Europe, Africa, southern and northern parts of East Asia, the Middle East, Siberia and the Americas. They found that after evolving for several thousand years in East Asia, a subgroup of dogs radiated out of southern East Asia about 15,000 years ago to the Middle East, Africa and Europe.

研究人员收集了来自世界各地的58种犬科动物的基因组序列，包括来自欧洲、非洲、东亚的南部和北部、中亚、西伯利亚和美洲的样本。他们发现，狗类在东亚经历了几千年的发展，大约在1.5万年前，狗的一个子群从东亚南部发展开来，到达中亚、非洲和欧洲。

"One of these out of Asia lineages then migrated back to northern China and made a series of admixtures with endemic East Asian lineages, before traveling to the Americas," said the researchers. "Our study, for the first time, reveals the extraordinary journey that the domestic dog has traveled on this planet during the past 33,000 years."

研究人员说：“这些脱离了亚洲血统的狗，有一些又迁移回到了中国北方，形成了一系列有东亚血统的杂交狗。之后，它们又迁徙到了美洲地区。我们的研究首次揭示了驯化狗在过去3.3万年里在地球上非同寻常的旅程。”

However, the researchers acknowledged that several basic aspects about the dog's origin and evolution are still debated over by scientists. For example, several different geographical regions have been proposed as the birthplace of domestic dogs, and the date of divergence between wolves and dogs has been estimated between 32,000 years ago and 10,000 years ago, according to the report.

不过研究人员承认，科学家们在狗狗起源和进化的几个基本方面仍在存在争议。比如，家犬的发源地就有好几个不同版本，而狼和狗的分化时间也从3.2万年前至1万年前不等。

"The exact history of dog domestication thus remains to be fully resolved."

“因此，狗驯化的确切过程仍有待进一步研究。”

Vocabulary

genome：基因组；染色体组

canid：犬科动物

lineage：血统；家系