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21英语教师网 > 备课资源 > 拓展阅读 > 正文
Express evolution
作者:21ST    来源:21英语网    日期: 2012-03-23

外研版高一年级:The violence of nature

关键词:Extreme weather and violent events

话题归类:自然Nature



 


人类是在不断进化的吗?



词数 284 建议阅读时间 6分钟 教案见网站

HUMANS are evolving (进化) more quickly than at any time in history, researchers say. In the past 5,000 years, humans have evolved up to 100 times more quickly than any time since they split (分离) with chimpanzees (黑猩猩) 6 million years ago, a team from the University of Wisconsin found.

The study also suggests that human races in different parts of the world are becoming genetically more distinct (独特的). But this trend is likely to change in the future as populations become more mixed.

There was a widespread assumption (设想) that human evolution has slowed down because we've conquered nature. That is not true, according to scientist Dr John Hawks, who led the study. "We didn't conquer nature, we changed it in ways that created new selection pressures on us," he said.

The researchers studied data from the international haplotype map of the human genome (国际单倍型基因图谱) and studied genes in 270 people from four groups: Han Chinese, Japanese, Africa's Yoruba and northern Europeans.

They found that at least seven percent of human genes have undergone recent evolution. The changes include lighter skin and blue eyes in northern Europe and resistance to diseases such as malaria (疟疾) among some African populations.

Some of the changes were traced back to just 5,000 years ago, and "today they appear in 30 or 40 percent of people because they are such an advantage," said Hawks.

The researchers believe that in the future, the trend to start families later in life will drive evolution. "People are having problems with infertility (不育), so any kind of genetic change that increases the success of later fertility will be selected," said Hawks.




关键词:关键词: 外研版 高一 The violence of nature 自然Nature







 

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