Human geneticists have turned to studies of twins .

人类遗传学家一直把注意力转向对双胞胎的研究。

Dna holds our genetic code , and geneticists have studied it for decades .

dna携带了我们的基因，基因学家已经研究dna几十年了。

In addition , within the last three years molecular geneticists have begun to extract dna from ancient human skeletons and compare the genes of japan 's ancient and modern populations .

而且，在过去的三年里，分子遗传基因学家已经开始从古代日本人骨骼中提取dna，并且用以比较古代日本人和现代日本人的基因。

Others are linked to conditions such as cancer or heart disease , which appear in later life , say geneticists .

其余的缺陷会在以后诱发，诸如癌症或心脏病等疾病，遗传学家们如是说。

In the past geneticists have concentrated on genes that have large individual effects when they go wrong , because such effects are easy to spot .

过去遗传学家都集中研究那些有了缺陷后会产生较大独特作用的基因，因为这样的作用容易被发现。