最近在PLoS Genetics雜志上刊登了一篇關(guān)于非洲基因流向歐洲南部的文章，HMS的科學(xué)家發(fā)現(xiàn)撒哈拉沙漠以南的非洲人基因流向了歐洲及中東,。雖然以前的研究證實(shí)共同祖先的存在,，但是基因是怎樣流向的還沒(méi)有進(jìn)行追溯,。
哈佛大學(xué)公共衛(wèi)生學(xué)院的科研項(xiàng)目公開(kāi)了40個(gè)人口群體的數(shù)據(jù)，其中包括北非,、中東及中亞地區(qū)的人口的數(shù)據(jù)分析,。他們用一種由德國(guó)的科學(xué)家研發(fā)出來(lái)新方法來(lái)追蹤祖先基因的流向，通過(guò)對(duì)比兩個(gè)群體的某些DNA片段的大小及組成,，從而評(píng)估兩個(gè)群體時(shí)何時(shí)發(fā)生交流的,，破碎得或較小的DNA片段越多，則交流時(shí)間越早,?？茖W(xué)家用這種方法評(píng)估了現(xiàn)代歐亞西部人群，發(fā)現(xiàn)這些人基因中具有撒哈拉以南非洲血統(tǒng)的特征,，且DNA數(shù)據(jù)顯示他們之間有密切的聯(lián)系,。通過(guò)計(jì)算這些基因片段的分布并且評(píng)估遺傳衰變率，可以得知在這些群體中非洲祖先基因的遺傳比例仍然存在,，并且可以推測(cè)歐亞西部與撒哈拉南部非洲人口發(fā)生交流的時(shí)間,。基因衰退非常緩慢,，因此幾千年后,，仍有足夠的證據(jù)證實(shí)基因曾經(jīng)交流過(guò)。
然而科學(xué)家發(fā)現(xiàn)歐洲北部人口并不存在具有非洲特征的基因,，這明顯區(qū)別存在于歐洲南部,、中東和猶太人群，現(xiàn)代歐洲南部人口群體中只有1%-3%的非洲特征基因,，交流可以追溯到55代之前,，大約在1600年前。中東人口群體中具有4%-12%的非洲遺傳基因,，大約為32代左右,。猶太群體大約為72代。
這些數(shù)據(jù)也得到歷史的證實(shí),，例如非洲與歐洲南部人口交流的時(shí)間正逢羅馬帝國(guó)和阿拉伯移民時(shí)期,。非洲與猶太人群體交流恰好發(fā)生在圣經(jīng)所記錄的時(shí)間，約在公元前8-6世紀(jì)的猶太人散居時(shí)期,。"我們的研究不能證明移民與考古學(xué)家對(duì)于圣經(jīng)中記錄的事件,，但是這是非常有意思的猜測(cè)。"研究人員說(shuō),。研究團(tuán)隊(duì)對(duì)德系與非德系猶太人擁有同一個(gè)祖先的結(jié)果非常驚訝,，這樣的研究結(jié)果對(duì)于遺傳學(xué)及歷史文化具有較大的沖擊。（生物谷Bioon.com）
生物谷推薦原文出處：
PLoS Genetics DOI：10.1371/journal.pgen.1001373
The History of African Gene Flow into Southern Europeans, Levantines, and Jews
Priya Moorjani, Nick Patterson, Joe N. Hirschhorn, Alon Keinan, Li Hao5, Gil Atzmon, Edward Burns, Harry Ostrer, Alkes L. Price, David Reich
Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas.
