The recent examples only serve to strengthen the argument that "morality" is decided by the majority and imposed on the minority via threat of punishment.
Instead of stealing, you set a slave free in the South. Your strong community will punish you until forcibly changed by a stronger force. Who is the "moral" person, the honorable slave holder or the slave thief?
If evolutionists spare the elderly and disabled out of fear of joining one of those groups, then they are acting contrary to improving the health of the species\herd. The weak should be culled. Instead you argue that they will act in whatever way benefits the individual.
A man cheats on his wife. He's just trying to spread his genes around and can't help it because evolution programmed him to do it.