英语听力文摘 English Digest 356、基因也疯狂（在线收听）

DNA Wrath of Khan
成吉思汗疯狂的基因

Today, Afghanistan is a war-torn region, battled over by military forces and world-spanning empires. Eight hundred years ago things were much the same. Only then, there was only one ruler: Genghis Khan.

Khan is one of the greatest conquerors who ever lived. Before he was finished, he had created an empire that ran all the way from the Caspian Sea to the Sea of Japan.

That’s the history  portion of our show. Now, on to the science. What is it that powerful males of the human species are after when they overrun other males? From an evolutionary point of view, the major objective is to spread their genes more effectively. And surprising, new data suggest Khan may have done that more successfully than anyone imagined.

Researcher Tatiana Zerjal, from the University of Oxford in England, and a team of geneticists took genetic samples of over twenty-one thousand men from all over Asia. They were looking for variations in certain genetic “markers,” or sequences of genes that tell you something about where people came from. To their astonishment, they found that one out of every twelve Asian men in regions once part of the Mongol empire carry a form of the Y chromosome that can be traced to Mongolia a thousand years ago. How did this genetic tag become so widespread?

Khan, they suggest. There is reason to believe that Khan himself, and thus his long-ruling descendants, had this particular form of Y chromosome. And though his power is long faded, the genetic empire of the conqueror is going strong–in roughly one out of every two hundred men alive today.

军队武力战争和帝国扩张疆土让如今的阿富汗饱受战乱之苦。早在800年前，阿富汗时局依旧，唯一不同的是只有一个统治者：成吉思汗。

成吉思汗是史上最伟大的征服者之一。成吉思汗生前征服的疆域从里海到日本海。

说完历史故事，让我们来说说科学吧。为什么强大的民族想要征服其它民族？从进化的角度说，其主要目的是开枝散叶。令人惊讶的是，新数据显示成吉思汗出人意外地成功做到了这一点。

牛津大学研究人员Tatiana Zerjal和一组基因学者采集了亚洲21000份基因样本，从中寻找某种基因“记号”或基因序列变化。基因序列可以识别出身。令人惊讶的是，他们发现曾是蒙古帝国疆域，每12个人中就有一人携带追溯到千年前的蒙古基因的Y染色体。为何这种基因“标签”流传如此之广？

研究人员猜测，有理由相信成吉思汗及长期统治的后裔都有这种特殊的Y染色体。虽然时至今日，成吉思汗的政权早已衰败，但是成吉思汗的基因却留在人们的血液中。今天，大概每200人中可能就有一人有这种基因。