There may not be an evolutionary advantage. Humans have developed empathy to care for each other, so many of us tend to do what we can to ensure that those who may have inherited or developed disadvantageous traits can still live full and happy lives, which also means those genes may be passed on to future generations. Hairy ears, wisdom teeth, color blindness, cystic fibrosis, etc. all may be disadvantageous genetic traits, but this presents the ethical question of if we would rather help the individuals with these genes be happy and reproduce, or if we would rather tell these people that they are forbidden from passing on these genes to protect the next generation from the afflictions (by way of genocide, selective breeding of humans, or gene selection and embryo screening).