Darwin not only tells us that one individual is not equal to another, he also tells us that races are the origin of species, which means that in general races will be unequal in major and important ways.
Darwinism also tells us that men and women are genetically predisposed to different and unequal social roles, which implies that attempts to make their roles legally equal will not work very well.
Darwinism tells us that we have a moral sense evolved to further our self interest, leading to the proposition that people’s real moral theory is closer to that of Ayn Rand or the classic Greeks, and that claims to the contrary are lies and hypocrisy. Darwinism tells us about our nature, and tells us about our moral sense, and what it tells us about our moral sense implies that the man who says he would hold a child’s face in the fire to find the cure for malaria is apt to hold a child’s face in the fire and forget he was trying to cure malaria
If you believe that men were not created equal, that some races really are inferior, that most endangered species are overdue for extinction and need to be turned into fur coats and hamburgers, that women should stay in the kitchen and if they must work, do female work, lest their delicate souls be shocked by male crudity, because if they are in the male workplace doing male jobs, they are apt sue their coworkers and bosses for being males, then Darwinism looks mighty like common sense.
If you believe that most people raising money to help far away strangers are going to use it to rape children, then Darwinism looks like realism rather than nihilism.
Darwinism should not cause you to doubt all morality. Darwinism tells us we evolved from killer apes by evolving towards more cooperation and more successful and effective cooperation. It should, however, cause you to doubt the morality of the Pharisees.