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科学家发现了人脑变大背后的基因

kira86 于2018-07-10发布 l 已有人浏览
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科学家们发现了三种可能在人类进化中起重要作用的基因,这些基因与人类祖先大脑变大有关。
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Scientists Identify Genes Behind Humans' Big Brains

科学家发现了人脑变大背后的基因

Scientists have identified three genes that may have played an important part in a major development in human evolution.

科学家们发现了三种可能在人类进化中起重要作用的基因。

The genes are being linked to the increase in brain size that took place in ancestors of human beings.This increase led to the development of mental abilities that define what it means to be human.

这些基因与人类祖先大脑变大有关。大脑变大促进了心智能力的发展,这些能力决定了对人类的意义。

Researchers published two reports on their observations of the genes in the publication Cell in late May.

5月下旬,研究人员在《细胞》杂志发表了两份关于基因观察的报告。

The researchers believe the genes first appeared between three and four million years ago.This was just before a period in the fossil record that shows a major brain enlargement in the species from which humans evolved.

研究人员认为这些基因最早出现在300万到400万年前。化石记录显示,人类从某一物种进化时大脑就存在变大的迹象,而此之前基因就已存在。

The three genes share almost the exact same qualities.Along with a fourth one that seems to serve no purpose, they are called NOTCH2NL genes.They came from a gene family believed to have developed hundreds of millions of years ago.They are also important in the development of embryos.

这三个基因具有几乎完全相同的特性。加上第四个似乎没有作用的基因,它们总称为NOTCH2NL基因。人们认为,它们来自一个数亿年前进化而来的基因家族。它们在胚胎发育中也很重要。

The NOTCH2NL genes are especially active in the collection of nerve stem cells in the cerebral cortex.The cerebral cortex is the outer part of the brain responsible for the highest mental processes.These include language, memory and reasoning.

NOTCH2NL基因在大脑皮层中的神经干细胞里尤其活跃。大脑皮层是大脑的外层,掌管意识活动。其中包括语言、记忆和推理。

The genes were found to slow the development of stem cells in the cerebral cortex into neurons in the embryo.The researchers say this delay leads to the production of a higher number of more developed nerve cells in this area of the brain.

研究发现,这些基因可以减缓大脑皮层干细胞向胚胎神经元的发育过程。研究人员说,这种延迟会导致大脑这个区域产生更多发达的神经细胞。

Pierre Vanderhaeghen is a developmental neurobiologist at the Universit? Libre de Bruxelles in Belgium.He told the Reuters news service that, in large part, the cerebral cortex is responsible for what defines humans as a species and as individuals.

皮埃尔·范德哈根是比利时布鲁塞尔自由大学的发育神经生物学家。他告诉路透社,大脑皮层在很大程度上解释了是什么将人类定义为物种和个体。

Understanding how it emerged in evolution is a fascinating question, touching at the basic origins of mankind, said Vanderhaeghen.

“理解它如何在进化中出现是一个很有趣的问题,涉及到人类的基本起源,”范德哈根说。

David Haussler is a biomolecular engineer and the scientific director of the University of California, Santa Cruz Genomics Institute.He added that it is "the ultimate evolutionary question" and a very interesting area of research in which to work.

大卫·豪斯勒是一名生物分子工程师,也是加州大学圣克鲁兹基因组研究所的科学主任。他补充说,这是“终极进化问题”,也是一个非常有趣的研究领域。

The species Australopithecus afarensis is an ancestor of humans that combined both ape-like and human-like qualities.The well-known fossil named "Lucy," discovered in Ethiopia in 1974, was a member of that species.Lucy lived in Africa at about the time these genes are believed to have appeared.

南方古猿阿法种是结合了类猿和类人特性的人类祖先。1974年在埃塞俄比亚发现的著名化石“露西”就是该物种的成员。人们认为,生活在非洲的露西所处时期就是这些基因出现的时期。

Sofie Salama is a UC-Santa Cruz biomolecular engineering research scientist.She said it would be great if it were possible to record the complete order of all of Lucy's genetic material, her DNA.But she noted that it would be nearly impossible.

苏菲·萨拉玛是加州大学圣克鲁斯分校生物分子工程研究科学家。她说,如果能够记录下露西所有遗传物质——她的DNA——的完整顺序,那就太好了。但她指出,这几乎是不可能的。

The NOTCH2NL genes are not present in the closest genetic relatives to human beings.None were found in monkeys or orangutans.

NOTCH2NL基因并不存在于与人类最近的基因亲属中。这些基因也不存在于猴子或猩猩身上。

However, Reuters reports that the researchers did find the genes in the remains of two human ancestor species: Neanderthals and Denisovans.

然而,路透社报道说,研究人员确实在两个人类祖先物种的遗骸中发现了这些基因,即尼安德特人和丹尼索瓦人。

NOTCH2NL gene abnormalities were found to be connected problems that affect the brain.These include autism, schizophrenia and both unusually large and unusually small head size.

人们发现NOTCH2NL基因的异常与影响大脑的问题有关。例如自闭症、精神分裂症以及大脑过大或过小。

I'm Pete Musto.

皮特·穆斯托为您播报。

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