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  3. Half a century before Charles Darwin published On the Origin of Species, the French naturalist Jean-Baptiste Lamarck outlined hi

Half a century before Charles Darwin published On the Origin of Species, the French naturalist Jean-Baptiste Lamarck outlined hi

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问题     Half a century before Charles Darwin published On the Origin of Species, the French naturalist Jean-Baptiste Lamarck outlined his own theory of evolution. A basis of this was the idea that characteristics acquired during an individual’s lifetime can be passed on to their offspring. In its day, Lamarck’s theory was generally ignored or lampooned.
    Now all that is changing. No one is arguing that Lamarck got everything right, but over the past decade it has become increasingly clear that environmental factors, such as diet or stress, can have biological consequences that are transmitted to offspring without a single change to gene sequences taking place. In fact, some biologists are already starting to consider this process as routine. However, fully accepting the idea, provocatively dubbed the "new Lamarckism", would mean a radical rewrite of modern evolutionary theory.
    That’s not all. The implications for public health could also be immense. Some researchers are talking about a paradigm shift in understanding the causes of disease. For example, non-genetic inheritance might help explain the current obesity epidemic, or why there are family patterns for certain cancers and other disorders, but no discernible genetic cause.
    Lamarck’s ideas about exactly how non-genetic inheritance might work were ambiguous at best. He wrote, for example, of the giraffe’s neck becoming elongated over generations because of the animal’s habit of stretching up to feed on leaves in high treetops. The recent research, by contrast, has a firm basis in biological mechanisms—in so-called "epigenetic" change.
    Their studies strongly suggest that a pregnant woman’s diet can affect her child’s epigenetic marks. So perhaps it is not surprising that the effect of certain nutrients is being called into question. And diet is not the only environmental factor that can influence the epigenetic setting of some genes. Michael Meaney at McGill University in Montreal, Canada, and colleagues have found that newborn mice neglected by their mothers are more fearful in adulthood—and that these mice show much higher than normal levels of methylation of certain genes involved in the stress response. In humans, too, there are troubling hints that damaging experiences early in life, while the brain is still developing, can affect epigenetic settings, perhaps with catastrophic consequences.
    In theory, epigenetic marks are wiped clear between generations in mammals. Intriguingly, though, the abnormalities in DNA methylation in scientists’ subjects were not restricted to their frontal cortex: they were also present in their sperm.
People start to question some nutrients’ effect probably because______.
选项 A、the experiments on mice have failed
B、they may affect brain development
C、mothers’ diet can influence children
D、they may disrupt normal biological mechanisms
答案C
解析 属信息推断题。题目的内容出现在文章第五段第二句，通过句子开头的so就可知道原因就在上文中。上一句提到母亲的饮食习惯能够影响孩子的表观遗传标记，因此可知选项C符合题意。选项A、B、D均是来自文章其他部分，与题目无关，因此均不符合题意。
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考研英语一

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