瑞典研究人員近日表示,，他們已經(jīng)進(jìn)一步證實(shí)了目前世界上所有種類的狗都起源于東亞南部某地馴養(yǎng)的狼，而非之前另一項(xiàng)研究所暗示的中東起源論,。其論文"Comprehensive study of mtDNA among Southwest Asian dogs contradicts independent domestication of wolf, but implies dog–wolf hybridization"發(fā)表于最新一期的《生態(tài)學(xué)與進(jìn)化》雜志網(wǎng)絡(luò)版上,。
瑞典皇家理工學(xué)院（KTH Royal Institute of Technology）的進(jìn)化遺傳學(xué)研究員彼得莎沃萊恩博士（Dr Peter Savolainen）表示，他們進(jìn)行的一項(xiàng)新的基因研究提供了強(qiáng)有力的證據(jù),，證實(shí)亞洲的長江以南地區(qū)是主要的,，可能也是唯一的狼被人類馴化的地區(qū)。
遺傳學(xué),、形態(tài)和習(xí)性數(shù)據(jù)清楚地表明,，狗是狼的后裔，但一直無法證明狗的起源地,。莎沃萊恩說：“現(xiàn)在我們對脫氧核糖核酸（DNA）Y染色體的分析證實(shí),，狼首次在亞洲的長江以南地區(qū)被馴養(yǎng)，我們稱之為ASY地區(qū),，在中國南部或東南亞,。線粒體DNA的Y染色體數(shù)據(jù)支持我們之前的一項(xiàng)研究。這兩項(xiàng)研究提供了非常有力的證據(jù),，表明狗起源于ASY地區(qū),。”
最近在《自然》雜志上發(fā)表的考古資料和遺傳研究稱，狗起源于中東,。但莎沃萊恩拒絕接受這一觀點(diǎn),。他說：“因?yàn)檫@些研究沒有包括從ASY地區(qū)采集的DNA樣本，ASY的證據(jù)被忽視了,。”
彼得 莎沃萊恩博士和博士生馬蒂亞斯 奧斯卡森（Mattias Oskarsson）以及中國同事對來自世界各地的公狗進(jìn)行DNA分析,，并識別出10組不同類型的DNA。他們的研究結(jié)果發(fā)表在《科學(xué)遺傳》雜志上,。他們在世界其它地區(qū)的狗身上只找到大約一半的基因庫,，而只有ASY地區(qū)具有最完整的遺傳多樣性，找到所有的10組DNA,。莎沃萊恩說：“這表明,，在世界所有其它地區(qū)的基因庫最有可能來自ASY地區(qū),。我們的研究結(jié)果證實(shí)，長江以南地區(qū)是最重要的,，可能是唯一的狼被馴化的地區(qū),，而且大量的狼被馴化。”
新的研究成果最近發(fā)表在《生態(tài)學(xué)和進(jìn)化》雜志上,，莎沃萊恩,、博士生阿爾曼 阿達(dá)蘭（ Arman Ardalan），以及伊朗和土耳其科學(xué)家對狗的線粒體DNA進(jìn)行了全面的研究,，重點(diǎn)針對中東的狗,。由于線粒體DNA只能從大多數(shù)物種的母系繼承，它在進(jìn)化關(guān)系研究中特別有用,。莎沃萊恩說：“由于其它研究表明,，狼馴化是在中東，為了確保我們的研究沒有失誤,，所以我們重點(diǎn)研究中東的狗,，但我們發(fā)現(xiàn)沒有任何跡象顯示狗起源于中東。”
此次研究不僅表明了犬類具有唯一的地理起源以及第一只狗來自于東亞南部,，還揭示了犬類的誕生源于對野生狼的大量馴養(yǎng),。在他們的研究中，研究人員還發(fā)現(xiàn)在某些地區(qū)出現(xiàn)過狗和狼之間的雜交現(xiàn)象,，包括中東地區(qū),。（生物谷Bioon.com）
doi:10.1002/ece3.35
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Comprehensive study of mtDNA among Southwest Asian dogs contradicts independent domestication of wolf, but implies dog–wolf hybridization
Ardalan, Arman; Kluetsch, Cornelya F. C.; Zhang, Ai‐ing; Erdogan, Metin; Uhlén, Mathias; Houshmand, Massoud; Tepeli, Cafer; Ashtiani, Seyed Reza Miraei; Savolainen, Peter
Studies of mitochondrial DNA (mtDNA) diversity indicate explicitly that dogs were domesticated, probably exclusively, in southern East Asia. However, Southwest Asia (SwAsia) has had poor representation and geographical coverage in these studies. Other studies based on archaeological and genome-wide SNP data have suggested an origin of dogs in SwAsia. Hence, it has been suspected that mtDNA evidence for this scenario may have remained undetected. In the first comprehensive investigation of genetic diversity among SwAsian dogs, we analyzed 582 bp of mtDNA for 345 indigenous dogs from across SwAsia, and compared with 1556 dogs across the Old World. We show that 97.4% of SwAsian dogs carry haplotypes belonging to a universal mtDNA gene pool, but that only a subset of this pool, five of the 10 principal haplogroups, is represented in SwAsia. A high frequency of haplogroup B, potentially signifying a local origin, was not paralleled with the high genetic diversity expected for a center of origin. Meanwhile, 2.6% of the SwAsian dogs carried the rare non-universal haplogroup d2. Thus, mtDNA data give no indication that dogs originated in SwAsia through independent domestication of wolf, but dog–wolf hybridization may have formed the local haplogroup d2 within this region. Southern East Asia remains the only region with virtually full extent of genetic variation, strongly indicating it to be the primary and probably sole center of wolf domestication. An origin of dogs in southern East Asia may have been overlooked by other studies due to a substantial lack of samples from this region.
