(单词翻译:单击)
Recording Three
录音3
Modern humans arose in Africa about 200,000 years ago.
现代人类起源于约20万年前的非洲。
They then spread across Europe and Asia sometime after 60,000 years ago.
然后，在6万年前的某个时候，人们遍布了欧洲和亚洲。
This is the "Out of Africa" model, as it's commonly known.
这就是众所周知的“走出非洲”模式。
In the 1990s, the hypothesis found widespread acceptance.
在20世纪90年代，这一假说被广泛接受。
But this popular idea is in need of revision, particularly given the number of important findings across Asia over the past few decades.
不过，这种流行的观点需要修正，特别是考虑到过去几十年亚洲各地的许多重要发现。
For instance, many new human fossils found, particularly in China, are now dated as older than 60,000 years.
例如，许多新发现的人类化石（特别是在中国出土的化石）的年代都超过了6万年。
This calls into question the idea that modern humans migrated out of Africa only 60,000 years ago.
这就对现代人类在6万年前才离开非洲的说法提出了质疑。
Take the recent discovery of two modern human teeth found in the Luna cave in China's Guangxi Zhuang Autonomous Region.
以最近在中国广西壮族自治区的卢娜洞穴发现的两颗现代人类牙齿为例。
When my research team and I dated these teeth, we found they were more than 70,000 years old—a situation clearly impossible if modern humans moved out of Africa only 60,000 years ago.
当我和我的研究团队对这些牙齿进行年代测定时，我们发现它们已经有7万多年的历史了--如果现代人在6万年前才离开非洲，这种情况显然是不可能的。
So with such findings, what happened exactly?
有了这些发现，我们想知道到底发生了什么?
Where does the most current data suggest we came from?
最新的数据表明我们到底从哪里来?
The first question we should ask is why did modern humans leave Africa to begin with?
我们要问的第一个问题是为什么现代人一开始要离开非洲?
If a population is perfectly adapted to a particular environment and has access to an abundance of resources, then there really is no reason to move or change.
如果一个种群完全适应了特定的环境，并且可以利用丰富的资源，那么就没有理由迁移或改变。
For instance, some monkeys in Africa have a set of teeth that has hardly changed over the course of millions of years, indicating that they found a place that has worked for them.
例如，非洲某些猴子的牙齿在数百万年的时间里几乎没有改变，这表明这些猴子找到了一个适合它们的地方。
So what happened with humans?
那么人类发生了什么呢?
Some researchers have suggested that population density increased to the point where smaller human groups were forced to explore new lands.
一些研究人员认为，人口密度的增加使得较小的人类群体被迫去探索新的土地。
Other researchers have suggested that due to major environmental events in East Africa, humans were prompted to find greener pastures.
其他研究人员认为，由于东非发生重大环境事件，促使人类去寻找更绿色的牧场。
Yet another explanation could simply be that early modern human hunters were following the large animals that they relied on, and so they moved out of Africa without realizing that they were actually moving from one continent to another.
然而，另一种解释可能是，早期现代人捕猎者一路跟随他们所依赖的大型动物，最后离开了非洲，也没有意识到他们实际上是从一个大陆迁移到了另一个大陆。
Humans need daily access to reliable fresh water, which appears to be absent from many coastal areas.
人类需要每天获取可靠的淡水，而许多沿海地区缺乏淡水。
This brings us to another question: by which route did modern humans move out of Africa?
这给我们带来了另一个问题: 现代人是通过哪条路线离开非洲的?
No clear routes across the Mediterranean from North Africa appear to be present, so the earlier dispersals out of Africa and into Europe and Asia might have been across the Arabian Peninsula.
目前还没有从北非穿越地中海的明确路线，所以早期从非洲扩散到欧洲和亚洲可能是通过阿拉伯半岛。
Questions 22 to 25 are based on the recording you have just heard.
请根据你刚刚听到的录音回答问题22至问题25。
Q22. What do we learn about modern humans according to the hypothesis commonly accepted in the 1990s?
问题22：根据20世纪90年代普遍接受的假说，我们了解现代人的什么信息?
Q23. What has called into question the "Out of Africa" model?
问题23：是什么让“走出非洲”模式受到质疑?
Q24. What does the speaker want to show with the example of some monkeys in Africa?
问题24：说话人想用一些非洲猴子的例子说明什么?
Q25. What question does the speaker raise close to the end of the talk?
问题25：说话人在演讲快结束时提出了什么问题?
