IN 2011 A team of geneticists(遗传学家) managed to(成功做到) recover centuries-old(数个世纪之久的) DNA from the teeth of bodies that had been buried in East Smithfield, a medieval cemetery in London. Besides human DNA, they were able to isolate(分离；隔离) genetic material from Yersinia pestis, the species(物种) of bacterium that causes plague. This let them confirm what historians had long suspected but had never quite been able to prove: that the Black Death, which killed perhaps half of Europe’s population between 1346 and 1353, was indeed an outbreak of plague.
2011年，一个遗传学家团队成功从埋藏在伦敦中世纪墓地东史密斯菲尔德尸体的牙齿中提取了几个世纪之久的DNA。除了人类DNA，他们还分离出了鼠疫耶尔森菌的遗传物质——这种细菌正是导致鼠疫的病原体。这让他们证实了历史学家长期怀疑但始终无法证明的事情：1346年至1353年间夺走欧洲约一半人口的黑死病，确实是一场鼠疫暴发。
For a field more used to pottery, ancient ruins and often unclear written records, such “ancient DNA” has been revolutionary(革命性的；突破性的). It has allowed scientists to reconstruct the history of plague in unprecedented detail(以前所未有的细节). Genomics has likewise confirmed that the Plague of Justinian, which struck the Byzantine empire between the years 541 and 549, was also caused by Y. pestis—although, interestingly, the strain(菌株；品系) responsible was not ancestral(祖先的；祖系的) to the one that devastated(毁灭；蹂躏) Europe 800 years later.
对于一个更习惯于陶器、古代遗址和常常模糊不清的文字记录的领域，这种“古DNA”具有革命性意义。它使科学家能够以前所未有的细节重建瘟疫的历史。基因组学同样证实了查士丁尼瘟疫——541年至549年间袭击拜占庭帝国的那场瘟疫——也是由鼠疫耶尔森菌引起的，尽管有趣的是，肇事的菌株并非800年后蹂躏欧洲的那一株的祖先。
The Plague of Justinian is the first big outbreak mentioned in the historical record. But DNA has proved that the disease goes far back into prehistory(史前时期), too. Now, in a paper published in Nature, Eske Willerslev, a geneticist at the University of Copenhagen and the University of Cambridge, and his colleagues describe the earliest evidence of plague to date: two lethal(致命的) outbreaks of the disease around 5,500 years ago among hunter-gatherers living near Lake Baikal, in what is these days called Siberia. Intriguingly(有趣地；引人入胜地), that is long before the appearance of the sorts of densely populated(人口稠密的), squalid(肮脏的；污秽的) cities—such as medieval London or ancient Constantinople—that had been thought to be necessary for big outbreaks of the disease.
查士丁尼瘟疫是历史记载中首次大规模暴发。但DNA证明该疾病也远溯至史前时期。如今，在《自然》杂志发表的一篇论文中，哥本哈根大学和剑桥大学的遗传学家埃斯克·威勒斯莱夫及其同事描述了迄今最早的瘟疫证据：约5500年前，在如今称为西伯利亚的贝加尔湖附近，狩猎采集者中发生了两次致命的瘟疫暴发。有趣的是，这远在那些被认为瘟疫大暴发所必需的密集、肮脏的城市——如中世纪伦敦或古君士坦丁堡——出现之前。