In fact, they might be slightly less fit due to a double dose of the gene.

事实是，他们可能因为携带了两份此种基因而导致其适应力下降几分。

youdao

Men with a double dose of the gene were twice as likely to have troubled marriages.

拥有双份这一基因的男性，其婚姻出现麻烦的可能性也是双倍。

youdao

Do not take a double dose of this medication. Do not double up the dose to catch up.

而就文中所介绍的药物，应当是“切勿一次服用两倍剂量”。

youdao

The target in Wales is to see 95% of children receive a double dose of the vaccine.

BBC: Jab reminder after measles cases

The Dodgers' feel-good spring was stymied by a double dose of bad news.

WSJ: MLB 2013: Challengers gear up to take down Giants

So some women might have a single dose of these genes while others will have a double dose.

ECONOMIST: Genetics