Original sentence: , refusing to patronize the only doctor in a town who could save you because he or she is black, or rejecting a potential friend/partner because of ethnicity).Biased views are necessary at times for human survival: we don't always have time to form a legitimate view about a potential foe before adopting a defensive stance that could save our lives
Edited sentence: , refusing to patronize the only doctor in a town who could save you because he or she is black, or rejecting a potential friend/partner simply because of a different ethnicity or gender).Biased views are necessary at times for human survival:  we don't always have time to form a legitimate view about a potential foe before adopting a defensive stance that could save our lives.Homosexuality causes one person to reject another simply on the basis of gender diversity, in the name of love.Similary, same-race orientation/bias causes one person to reject another simply on the basis of racial diversity