瑞典皇家理工学院科学家近日确认了犬类的起源地点和时间:目前世界所有种类的狗都起源于约1.6万年前中国长江流域南部驯养的狼。相关报告刊发在最新一期《分子生物学和进化》杂志上。
研究人员通过线粒体脱氧核糖核酸(DNA)技术对来自亚洲、非洲和欧洲1500多种狗的基因进行分析,并识别出10组不同类型的DNA。他们在欧洲狗身上只找到其中4组,而在中国云南省和贵州省的狗身上则找到所有的10组DNA。
皇家理工学院的生物学家彼得·萨弗莱宁表示,这是第一次为犬类的诞生提供较为详细的信息,如其发源地和时间以及被驯化的狼群数量等。之前的研究虽已指出狼群在东亚经过驯化演变成了犬类,但具体细节并不知晓。
萨弗莱宁与瑞典同事以及来自中国的研究团队一道对犬类的历史进行了研究,并取得了一系列新的发现。他们认为,犬类出现在1.6万年前的中国长江流域南部。相比其之前提出的诞生地点和时间,此次的研究结果更为具体和清晰,从而更具说服力。
而在1万至1.2万年前,随着犬类的出现,中国长江流域人员的职业已从猎户或是(草药、果实)采集者转变成了农民,犬类诞生的时间段与该地区人口的职业变化准确地契合在了一起。
萨弗莱宁表示,此次研究不仅表明了犬类具有唯一的地理起源,还揭示了犬类的诞生源于对动物的大量驯养。目前已知的被驯化狼群数量就高达数百只或者更多。“由大量狼只进化为最初犬类的事实证明了这是当时的文化中十分重要的组成部分”。
他们的种种新发现同时也衍生出了很多令人惊讶的理论。比如研究人员认为,最早的犬类并不像它们在欧洲的后代一样,被人们当作可以信赖的牧羊者或是看家护院的“警卫”,而是很有可能被当时的人们当作了充饥之物,在人类的胃里结束了自己的生命。(生物谷Bioon.com)
生物谷推荐原始出处:
Molecular Biology and Evolution, doi:10.1093/molbev/msp195
mtDNA Data Indicates a Single Origin for Dogs South of Yangtze River, less than 16,300 Years Ago, from Numerous Wolves
Jun-Feng Pang1,2,#, Cornelya Kluetsch3,#, Xiao-Ju Zou2,#, Ai-bing Zhang3,#, Li-Yang Luo1,4, Helen Angleby3, Arman Ardalan3,5,6, Camilla Ekstr?m3, Anna Sk?llermo3, Joakim Lundeberg3, Shuichi Matsumura7,8, Thomas Leitner9, Ya-Ping Zhang1,2,* and Peter Savolainen3,*
1 State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
2 Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming 650091, China
3 Department of Gene Technology, School of Biotechnology, KTH-Royal Institute of Technology, Roslagstullsbacken 21, 10691 Stockholm, Sweden
4 College of Wildlife Resource, Northeast Forestry University, No. 26 Hexing Road, Harbin 150040, China
5 National Institute of Genetic Engineering and Biotechnology (NIGEB), 14965/161 Tehran, Iran
6 School of Agronomy and Animal Science, University of Tehran, 4111 Karaj, Iran
7 Evolution and Ecology Program, International Institute for Applied Systems Analysis, Schlossplatz 1, 2361 Laxenburg, Austria
8 Department of Fish Biology and Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Muggelseedamm 310, 12587 Berlin, Germany
9 Theoretical Biology and Biophysics, MS K710, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
There is no generally accepted picture of where, when, and how the domestic dog originated. Previous studies of mitochondrial DNA (mtDNA) have failed to establish the time and precise place of origin because of lack of phylogenetic resolution in the so far studied control region (CR), and inadequate sampling. We therefore analysed entire mitochondrial genomes for 169 dogs to obtain maximal phylogenetic resolution, and the CR for 1,543 dogs across the Old World for a comprehensive picture of geographical diversity. Hereby, a detailed picture of the origins of the dog can for the first time be suggested. We obtained evidence that the dog has a single origin in time and space, and an estimation of the time of origin, number of founders and approximate region, which also gives potential clues about the human culture involved. The analyses showed that dogs universally share a common homogenous gene pool containing 10 major haplogroups. However, the full range of genetic diversity, all 10 haplogroups, was found only in south-eastern Asia south of Yangtze River, and diversity decreased following a gradient across Eurasia, through 7 haplogroups in Central China, and 5 in North China and Southwest Asia, down to only 4 haplogroups in Europe. The mean sequence distance to ancestral haplotypes indicates an origin 5,400-16,300 years ago from at least 51 female wolf founders. These results indicate that the domestic dog originated in southern China less than 16,300 years ago, from several hundred wolves. The place and time coincide approximately with the origin of rice agriculture, suggesting that the dogs may have originated among sedentary hunter-gatherers or early farmers, and the numerous founders indicate that wolf taming was an important culture trait.