Evolution has given us a blessing and a curse.
It has given us empathy so that we cooperate, and it is given us selfishness that we might survive.
The empathy allows us to love, the selfishness allows us to hurt and harm.
We can think of evolution as given us a good side and a bad side. Empathy is the good of human nature, selfishness is the bad of human nature.
Even Christianity recognizes that we have the higher nature and the lower nature, which it calls flesh and spirit.
Taoism as well talks about the light side of the dark side, the yin and the yang.
All this can be traced back to evolution giving us empathy and selfishness.