题目选项分析

Although said to be consistent between individuals to one part in ten thousand, the homogeneity of the human genetic record has heretofore been explained by environmental factors and may be equally accounted for by the theory of convergent evolution.

The homogeneity of the human genetic record, which is said to be consistent between individuals to one part in ten thousand, has heretofore been attributed to environmental factors; the theory of convergent evolution, however, may also be able to explain it.