题目选项分析

In California, a lack of genetic variation in the Argentine ant has allowed the species to spread widely; because of being so genetically similar to one another, the ants consider all their fellows to be a close relative and thus do not engage in the kind of fierce intercolony struggles that limits the spread of this species in its native Argentina.

In California, a lack of genetic variation in the Argentine ant has allowed the species to spread widely; because they are so genetically similar to one another, the ants consider all their fellows to be close relatives and thus do not engage in the kind of fierce intercolony struggles that limit the spread of this species in its native Argentina.