EVIDENCE FOR 2 INDEPENDENT DOMESTICATIONS OF CATTLE
EVIDENCE FOR 2 INDEPENDENT DOMESTICATIONS OF CATTLE
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DOI：
10.1073/pnas.91.7.2757
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发表时间：
1994-03-29
影响因子：
11.1
通讯作者：
CUNNINGHAM, P
中科院分区：
文献类型：
--
作者：
LOFTUS, RT;MACHUGH, DE;CUNNINGHAM, P
牛的起源和分类地位是有争议的。瘤牛和牛磺酸品种的区别主要在于是否有驼峰，并被认为是独立的物种（Bos indicus和Bos taurus）。然而，最普遍的观点是，这两种类型的牛都来自8000- 10000年前的单一驯化事件。我们已经研究了mtDNA序列的代表六个欧洲（牛磺酸）品种，三个印度（瘤牛）品种，和四个非洲（三个瘤牛，一个牛磺酸）品种。在每个主要大陆组的动物中观察到相似水平的平均序列差异：0.41%（欧洲），0.38%（非洲）和0.42%（印度）。然而，序列落入两个非常不同的地理谱系，不符合牛磺酸-瘤牛二分法：所有欧洲和非洲品种在一个谱系，所有印度品种在另一个谱系。几乎没有迹象表明品种集群内的任何血统。分子钟的应用表明，这两个主要的mtDNA分支至少在20万年前，甚至可能在100万年前发生了分歧。这种相对较大的差异被简单地解释为两个独立的驯化事件的证据，可能是欧洲野牛的不同亚种。牛磺酸谱系内的所有非洲瘤牛mtDNA序列的聚类归因于与早期B的祖先杂交。大陆上的金牛座居民。
The origin and taxonomic status of domesticated cattle are controversial. Zebu and taurine breeds are differentiated primarily by the presence or absence of a hump and have been recognized as separate species (Bos indicus and Bos taurus). However, the most widely held view is that both types of cattle derive from a single domestication event 8000-10,000 years ago. We have examined mtDNA sequences from representatives of six European (taurine) breeds, three Indian (zebu) breeds, and four African (three zebu, one taurine) breeds. Similar levels of average sequence divergence were observed among animals within each of the major continental groups: 0.41% (European), 0.38% (African), and 0.42% (Indian). However, the sequences fell into two very distinct geographic lineages that do not correspond with the taurine-zebu dichotomy: all European and African breeds are in one lineage, and all Indian breeds are in the other. There was little indication of breed clustering within either lineage. Application of a molecular clock suggests that the two major mtDNA clades diverged at least 200,000, and possibly as much as 1 million, years ago. This relatively large divergence is interpreted most simply as evidence for two separate domestication events, presumably of different subspecies of the aurochs, Bos primigenius. The clustering of all African zebu mtDNA sequences within the taurine lineage is attributed to ancestral crossbreeding with the earlier B. taurus inhabitants of the continent.