This created a serious lack of genetic variability in the potatoes grown in Ireland, which made them far more susceptible to disease.

这造成了爱尔兰种植的马铃薯严重缺乏遗传变异，使它们更容易患病。

Since the dawn of time, several billion human (or humanlike) beings have lived, each contributing a little genetic variability to the total human stock.

自从人类起源以来，有几十亿人（或类人动物）曾经生活过，每一个都把一点儿不同的基因遗传给整个人类。