In the interests of children–whose well-being ought to come before that of any adults’–adoptable children ought to be matched most closely to their prospective parents. It isn’t that this guarantees a closer bond; but it represents a feasible means of bettering the chances for one.
Accordingly, African-American parents ought to take priority in the adoption of African-American babies; and, unless a test were devised to determine sexual orientation by genetic sampling, heterosexual parents ought to have priority in the adoption of all children, in relation to homosexual couples, because children are so much more likely to be heterosexual.
If a genetic test for homosexuality were devised–and also accepted by the homosexual community–then a child determined to be so–or at least predisposed to be–would be available first to homosexual couples as an acceptable, if unequal, preference. This is the adult version of equal rights, where the well-being of innocent children supersedes the self-centered needs of adults.