But the 20th century suffered "two" ideologies that led to genocides. The other one, Marxism, had no use for race, didn't believe in genes and denied that human nature was a meaningful concept. Clearly, it's not an emphasis on genes or evolution that is dangerous. It's the desire to remake humanity by coercive means (eugenics or social engineering) and the belief that humanity advances through a struggle in which superior groups (race or classes) triumph over inferior ones.
Evolutionary psychologists seem to want to unmask our noblest motives as ultimately self-interested - to show that our love for children, compassion for the unfortunate and sense of justice are just tactics in a Darwinian struggle to perpetuate our genes.
I think that communism was a major force for violence for more than 100 years, because it was built into its ideology - that progress comes through class struggle, often violent.