Domestic dog origins challenged 家狗起源问题遭质疑
文章来源:未知 文章作者:meng 发布时间:2009-08-04 05:58 字体: [ ]  进入论坛
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The suggestion that the domestic dog originated in East Asia has been challenged.

家养狗起源于东亚的意见遭到质疑。

African village dogs possess plenty of <a href=genetic1 diversity" width="466" border="0" src="/upimg/090804/4_061116_1.jpg" />
African village dogs possess plenty of genetic diversity

The huge genetic diversity of dogs found in East Asia had led many scientists to conclude that domestication2 began there.

But new research published in the journal PNAS shows the DNA3 of dogs in African villages is just as varied4.

An international group of researchers analysed blood samples from dogs in Egypt, Uganda and Namibia.

Today's dogs are descended5 from Eurasian grey wolves, domesticated6 between 15,000 and 40,000 years ago.

The authors say the process by which humans domesticated the dog is poorly understood.

Lead scientist, Dr Adam Boyko of the Department of Biological Statistics and Computational Biology at Cornell University, says he decided7 to look at village dogs because they are so much more genetically8 diverse than bred dogs that they may hold the key to the origins of dog domestication.

The team analysed DNA from 318 dogs from villages in Egypt, Uganda and Namibia and measured their genetic diversity.

They also analysed the genetic make up of dog breeds thought to be of African origin, for example the Saluki, the Rhodesian Ridgeback, and the Pharoah Hound and compared all the resulting data with results for non African dogs such as Puerto Rican street dogs and non-pedigree(纯种的) dogs in the US.

The emphasis on African village dogs came about because Adam Boyko's co-authors, his brother and sister-in-law, were travelling in Africa on honeymoon9. They collected all the blood samples from the African dogs.

Genetically diverse

The team found genetic diversity among African village dogs is just as diverse as that of East Asian dogs, leading them to question the hypothesis(假设) of an East Asian origin for dog domestication.

Dr Boyko told BBC News: "I think it means that the conclusion that was drawn10 before might have been premature11. It's a consequence of having a lot of street dogs from East Asia that were sampled, compared to elsewhere.

"The reason that East Asia looked more diverse than elsewhere was not because East Asia as a continent had more diverse dogs than elsewhere but because non breed street and village dogs are more diverse than breed dogs."

He said he was not ruling out East Asia as a possible location for the origin of the domestic dog - but it could equally have been anywhere else on the Eurasian landmass(大陆) where there were both grey wolves and humans.

Co-author Paul Jones of The Waltham Centre for Pet Nutrition, UK, said: "It's interesting to know the answer to the question of where dogs were first domesticated(驯服的,驯养的) and this paper goes some way to giving us an answer."

The team are now in the process of sampling street and village dogs across Europe and Asia from Portugal to Papua New Guinea to pinpoint12 the areas of greatest genetic diversity.

Dr Boyko said that all the dogs sampled in the study have grey wolf DNA so he is not questioning the hypothesis that dogs descended from Eurasian wolves.

The results led the team to conclude that today's African village dogs are a mosaic13(马赛克,镶嵌细工) of indigenous14(土著的,国产的) dogs descended from early migrants to Africa.

They also went some way to proving the origins of some pedigree dogs purported15(传说的,谣传的) to be of African origin. For example the Saluki breed shares DNA with modern day village dogs from Egypt - as does the Afghan Hound, despite its name.

Likewise, the Basinji breed is genetically very similar to some Namibian and Ugandan village dogs.

However the Pharaoh Hound and Rhodesian Ridgeback have little in common with any African indigenous dogs which suggests that these two breeds have non African origins.



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1 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
2 domestication a412c94ddc4dddbce0e57281001e9ede     
n.驯养,驯化
参考例句:
  • The first was the domestication of animals. 第一个阶段是驯养动物。 来自《简明英汉词典》
  • In northwestern China, there is no evidence for endemic domestication of any animals. 在中国西北,没有任何当地动物驯化的迹象。 来自辞典例句
3 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
4 varied giIw9     
adj.多样的,多变化的
参考例句:
  • The forms of art are many and varied.艺术的形式是多种多样的。
  • The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。
5 descended guQzoy     
a.为...后裔的,出身于...的
参考例句:
  • A mood of melancholy descended on us. 一种悲伤的情绪袭上我们的心头。
  • The path descended the hill in a series of zigzags. 小路呈连续的之字形顺着山坡蜿蜒而下。
6 domesticated Lu2zBm     
adj.喜欢家庭生活的;(指动物)被驯养了的v.驯化( domesticate的过去式和过去分词 )
参考例句:
  • He is thoroughly domesticated and cooks a delicious chicken casserole. 他精于家务,烹制的砂锅炖小鸡非常可口。 来自《简明英汉词典》
  • The donkey is a domesticated form of the African wild ass. 驴是非洲野驴的一种已驯化的品种。 来自《简明英汉词典》
7 decided lvqzZd     
adj.决定了的,坚决的;明显的,明确的
参考例句:
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
8 genetically Lgixo     
adv.遗传上
参考例句:
  • All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
  • Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物
9 honeymoon ucnxc     
n.蜜月(假期);vi.度蜜月
参考例句:
  • While on honeymoon in Bali,she learned to scuba dive.她在巴厘岛度蜜月时学会了带水肺潜水。
  • The happy pair are leaving for their honeymoon.这幸福的一对就要去度蜜月了。
10 drawn MuXzIi     
v.拖,拉,拔出;adj.憔悴的,紧张的
参考例句:
  • All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
  • Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。
11 premature FPfxV     
adj.比预期时间早的;不成熟的,仓促的
参考例句:
  • It is yet premature to predict the possible outcome of the dialogue.预言这次对话可能有什么结果为时尚早。
  • The premature baby is doing well.那个早产的婴儿很健康。
12 pinpoint xNExL     
vt.准确地确定;用针标出…的精确位置
参考例句:
  • It is difficult to pinpoint when water problems of the modern age began.很难准确地指出,现代用水的问题是什么时候出现的。
  • I could pinpoint his precise location on a map.我能在地图上指明他的准确位置。
13 mosaic CEExS     
n./adj.镶嵌细工的,镶嵌工艺品的,嵌花式的
参考例句:
  • The sky this morning is a mosaic of blue and white.今天早上的天空是幅蓝白相间的画面。
  • The image mosaic is a troublesome work.图象镶嵌是个麻烦的工作。
14 indigenous YbBzt     
adj.土产的,土生土长的,本地的
参考例句:
  • Each country has its own indigenous cultural tradition.每个国家都有自己本土的文化传统。
  • Indians were the indigenous inhabitants of America.印第安人是美洲的土著居民。
15 purported 31d1b921ac500fde8e1c5f9c5ed88fe1     
adj.传说的,谣传的v.声称是…,(装得)像是…的样子( purport的过去式和过去分词 )
参考例句:
  • the scene of the purported crime 传闻中的罪案发生地点
  • The film purported to represent the lives of ordinary people. 这部影片声称旨在表现普通人的生活。 来自《简明英汉词典》
TAG标签: dog domestic origin
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