科學家說，尼安德特人和現(xiàn)代人類祖先之間的異血緣性接觸比我們原先的印象要更早。從一名尼安德特人染色體里發(fā)現(xiàn)的現(xiàn)代人祖先的 DNA 痕跡說明，現(xiàn)代人類祖先 與尼安德特人開始交配融合的時間比已知時間要早四萬年。以下是 BBC Rebecca Morelle 的報道：
The ancient remains of a female Neanderthal found in a remote cave in the mountains of Siberia are the source of the latest revelations about the sex lives of our ancestors. Hidden within her genome are traces of DNA from modern humans which reveal a genetic crossover that took place 100,000 years ago.
It means that we were interbreeding with our heavy-browed, stocky and now extinct relatives much earlier than was thought. Previous research had suggested that the two species first mixed about 60,000 years ago when humans migrated out of Africa and started to spread around the world. As they left the continent they met and mingled with the Neanderthals, who lived across Europe and Asia.
But the finding that interbreeding took place tens of thousands of years before suggests that some early humans left Africa way ahead of the crowds. However the circumstances behind these early interspecies encounters remain unclear and whether they took place by choice or by force is not known.
詞匯表
remote 遙遠的，偏遠的
ancestors 祖先
crossover 交叉
extinct 絕種的，已經(jīng)滅絕的
migrated 遷徙，移居
mingled 融合，（此處）交配
circumstances 境況，情形
測驗
請聽報道并回答下列問題。
1. When did interbreeding between humans and Neanderthals first take place?
2. Where did humans meet the Neanderthals?
3. What does the reporter mean by "ahead of the crowds"?
4. Were humans forced to interbreed with Neanderthals?
答案
1. When did interbreeding between humans and Neanderthals first take place?
According to new research, 100,000 years ago.
2. Where did humans meet the Neanderthals?
They met in Europe and Asia, where the Neanderthals lived.
3. What does the reporter mean by "ahead of the crowds"?
Reporter Rebecca Morelle means that some humans started migrating out of Africa much earlier than the bigger migration which took place later on.
4. Were humans forced to interbreed with Neanderthals?
We don't know for sure. According to the report, the circumstances behind these early encounters are not clear. The researchers don't know whether they took place by choice or by force.
