VOA标准英语2012--Genome Shows Humans More Gorilla-like than Thought

Genome Shows Humans More Gorilla¹-like than Thought

Sixty scientists worked over five years to sequence the genome of a single female lowland gorilla, the last of the great apes to have its DNA² mapped. 

According to lead author Aylwyn Scally, of the Trust Genome Campus of the Wellcome Trust Sanger Institute in England, even with that evolutionary³ distance, humans and gorillas⁴ have a lot more in common, genetically⁶, than previously⁷ thought.

“The passage of ancestry⁸ across the three genomes changes from position to position," Scally says. "Although most of the human genome is indeed closer to chimpanzee on average, there’s a sizable minority, 15 percent is in fact closer to gorilla. And another 15 percent is where chimpanzee and gorilla are closest.” 

Ninety-eight percent of human and gorilla genes⁹ are identical; humans and chimps¹⁰ share 99 percent of their DNA. Co-author Chris Tyler-Smith, also with the Wellcome Trust Sanger Institute, says it’s those relatively¹¹ few genes that differ between the species that are of special interest. 

Genes tell a story

For example, the study finds that a single gorilla gene⁵ associated with enhanced production of keratin - a protein that toughens the apes’ fingernails, skin and especially their knuckle¹² pads - is absent from the human genome. 

A group of genes, associated with hearing, tells another story. 

“It’s been known for some time that hearing genes in humans have shown accelerated evolution," Tyler-Smith says, "but what we could see by sequencing the gorilla genome was that this acceleration¹³ goes back millions of years. So the implication of that is that this is not because of human language ability, it must be for some broader role that these play.”

The gorilla genome sequencing also identified several genes that cause disease in humans, but not in gorillas. One gene leads to a form of human dementia, a second is associated with heart failure in people. 

“If we could understand more about why those variants¹⁴ are so harmful in humans, but not in gorillas, that would have important or useful medical implications,” says Tyler-Smith, who intends to explore the ancestral family tree further, to learn what happened as humans and apes evolved on their separate paths. 

He says the gorilla sequence is a template that will help to explain many of those evolutionary mysteries.

1 gorilla   

n.大猩猩，暴徒，打手

参考例句：

• I was awed by the huge gorilla.那只大猩猩使我惊惧。
• A gorilla is just a speechless animal.猩猩只不过是一种不会说话的动物。

2 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

3 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

4 gorillas   

n.大猩猩( gorilla的名词复数 )；暴徒，打手

参考例句：

• the similitude between humans and gorillas 人类和大猩猩的相像
• Each family of gorillas is led by a great silverbacked patriarch. 每个大星星家族都由一个魁梧的、长着银色被毛的族长带领着。 来自《简明英汉词典》

5 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

6 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

7 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

8 ancestry   

n.祖先，家世

参考例句：

• Their ancestry settled the land in 1856.他们的祖辈1856年在这块土地上定居下来。
• He is an American of French ancestry.他是法国血统的美国人。

9 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

10 chimps   

（非洲）黑猩猩( chimp的名词复数 )

参考例句：

• Chimps are too scarce, and too nearly human, to be routinely slaughtered for spare parts. 黑猩猩又太少，也太接近于人类，不可以作为人器官备用件说杀就杀。 来自英汉非文学 - 生命科学 - 医学的第四次革命
• And as nonprimates, they provoke fewer ethical and safety-related concerns than chimps or baboons. 而且作为非灵长类，就不会产生像用黑猩猩或狒狒那样的伦理和安全方面的顾虑。 来自英汉非文学 - 生命科学 - 医学的第四次革命

11 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

12 knuckle   

n.指节；vi.开始努力工作；屈服，认输

参考例句：

• They refused to knuckle under to any pressure.他们拒不屈从任何压力。
• You'll really have to knuckle down if you want to pass the examination.如果想通过考试，你确实应专心学习。

13 acceleration   

n.加速，加速度

参考例句：

• All spacemen must be able to bear acceleration.所有太空人都应能承受加速度。
• He has also called for an acceleration of political reforms.他同时呼吁加快政治改革的步伐。

14 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句