1.   Heterosexual brothers in the group did not.

2.   However, the second study goes further than the first by including in the analysis heterosexual brothers of the homosexual pairs.

3.   The inclusion of heterosexual brothers in the new study answers one of the criticisms of its predecessor.

4.   This time, Dr. Hamer looked at the DNA not only of a fresh set of gay brothers, but also of their heterosexual brothers.