基因研究發現狗起源於中國

A new scientific research report has found strong evidence suggesting that man's best friend originated from China some 33,000 years ago.
一項最新的科學研究發現了有力證據，證明人類最好的朋友——狗，起源於大約3.3萬年前的中國。

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.
研究結果已發表在科學雜誌《細胞研究》上。該研究稱，中國本地狗是狼與狗的中間體，沒有經歷過激烈的人工選擇。

"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.
報告稱：“因此，對中國本地狗的分析讓我們可以對狗的馴化過程進行分類，進而調查“正向選擇”在馴化第一階段發揮的具體作用”。

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.
研究人員還發現，中國南方的狗以及一些東亞的狗品種（如雄獅狗和沙皮狗）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.
狗的馴化歷史可分爲兩個階段，原始的狗最初由它們“野生的祖先（即灰狼）”馴化而來。在第二階段，原始種類被進一步選擇，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.
研究人員收集了來自世界各地的58種犬科動物的基因組序列，包括來自歐洲、非洲、東亞的南部和北部、中亞、西伯利亞和美洲的樣本。他們發現，狗類在東亞經歷了幾千年的發展，大約在1.5萬年前，狗的一個子羣從東亞南部發展開來，到達中亞、非洲和歐洲。

"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."
研究人員說：“這些脫離了亞洲血統的狗，有一些又遷移回到了中國北方，形成了一系列有東亞血統的雜交狗。之後，它們又遷徙到了美洲地區。我們的研究首次揭示了馴化狗在過去3.3萬年裏在地球上非同尋常的旅程。”

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.
不過研究人員承認，科學家們在狗狗起源和進化的幾個基本方面仍在存在爭議。比如，家犬的發源地就有好幾個不同版本，而狼和狗的分化時間也從3.2萬年前至1萬年前不等。

"The exact history of dog domestication thus remains to be fully resolved."
“因此，狗馴化的確切過程仍有待進一步研究。”

Vocabulary
genome：基因組；染色體組
canid：犬科動物
lineage：血統；家系