【英语时差8,16】M&M巧克力豆与遗传漂变（上）

 We’ve discussed before how endangered species are at risk from the increased likelihood of inbreeding, which leads to unhealthy offspring. But there’s another danger to letting the numbers of animals in a given species become too low. It’s called genetic¹ drift. Genetic drift is the term biologists use to describe the gradual loss of certain genes² from a species–genes that may have been very important for that species’ survival. How Can Animals Lose Genes? It’s kind of like reaching into a bag of M&Ms. If you take out a hundred M&Ms you are sure to get all the colors at least once. If you only take out ten, you may well miss a color. And if by chance you haven’t missed a color, try it again. Very soon you will come up with, say, no reds.

1 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪