2021年经济学人 基因一小步,世界一大步(2)

The evolutionary¹ line leading to Homo sapiens diverged² 5m-6m years ago from that leading to chimpanzees, and for almost all that time the ancestors of modern humans lived in Africa.

在500万至600万年前，智人的进化路线与黑猩猩的进化路线分道而行，而且现代人类的祖先几乎一直都生活在非洲。

Only about 60,000 years ago did Homo sapiens venture widely beyond the continent, in small bands of adventurers. Most of humanity’s genetic³ diversity, undersampled though it is, is therefore found in Africa. Unfortunately, that diversity is also reflected in the greater variety of genetic illnesses found there.

仅仅在大约60000年前，组成冒险家小群体的智人冒险远涉非洲大陆以外的地方。因此，尽管样本不足，但大多数人类遗传多样性都能在非洲发现。不幸的是，这种多样性也反映在非洲发现的更多种类的遗传病上。

The bias⁴ in sequencing leads to underdiagnosis of diseases in people of (relatively recent) African descent. Genetic causes of heart failure, such as the one that caused the ultimately fatal collapse⁵ of Marc-Vivien Foé, a Cameroonian football player, during a game in 2003, are poorly understood. The variation present in most non-Africans with cystic fibrosis is responsible for only about 30% of cases in people of African origin. This is one reason, along with its relative rarity, that the illness is often missed in black children. Standard genetic tests for hearing loss would not have picked up the Mutambara boys’ variations. And such is the diversity within the continent that tests in some countries would be irrelevant⁶ in others. In Ghana HI-GENES found one mutation⁷ responsible for 40% of inherited deafness. The same variation has not been found in South Africa.

测序的偏差导致对（相对较新的）非洲人后裔疾病的诊断不足。人们对心脏衰竭的遗传原因了解甚少，比如最终导致喀麦隆足球运动员马克-维维安·福在2003年的一场比赛中心力衰竭而死的原因尚不可知。基因突变引起的囊性纤维化是大多数非非洲人心力衰竭的原因，因这一遗传原因发病的非洲人只有30%。这是黑人儿童很少患有该病的原因之一，另一个原因则是它相对罕见。对听力损失的标准基因测试无法检测出穆坦巴拉家两个男孩的变异。非洲大陆的遗传疾病多样性使得一些国家的测试在其他国家无关紧要。在加纳，HI-GENES发现了一个导致40%的遗传性耳聋的突变。但南非没有发现同样的变异。

1 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。

2 diverged   

分开( diverge的过去式和过去分词 )； 偏离； 分歧； 分道扬镳

参考例句：

• Who knows when we'll meet again? 不知几时咱们能再见面！
• At what time do you get up? 你几时起床？

3 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。

4 bias   

n.偏见，偏心，偏袒；vt.使有偏见

参考例句：

• They are accusing the teacher of political bias in his marking.他们在指控那名教师打分数有政治偏见。
• He had a bias toward the plan.他对这项计划有偏见。

5 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

6 irrelevant   

adj.不恰当的，无关系的，不相干的

参考例句：

• That is completely irrelevant to the subject under discussion.这跟讨论的主题完全不相关。
• A question about arithmetic is irrelevant in a music lesson.在音乐课上，一个数学的问题是风马牛不相及的。

7 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。