I think that traits have to be sufficiently detrimental to reproductive success for evolution to remove them. For example a genetic predisposition for cancer i

I think that traits have to be sufficiently detrimental to reproductive success for evolution to remove them. For example a genetic predisposition for cancer in old age is unlikely to have an effect on reproductive success. Whilst a gene that reduces fertility in young people would. It is possible that things like art and music are the result of traits in our genome that are beneficial in other ways. Or the traits just didn't inhibit reproduction. Maybe a hypothetical "gay gene" could have survived in women simply because they historically lacked choice about reproduction.