same reason left handed people exist
not everything about the genome is necessarily hereditary and not all hereditary traits must be positive for survival... just enough.
y isnt homosexuality classified as a mental illness
its still not a hereditary trait. a 2 left handed couple doesnt have a higher chance of having a lefthanded kid
its probably not even detectable until an early stage of brain development. where some neuron or two zigged instead of zagged.
if its genetic i mean if ur gay u dont pass ur genetics down a generation
so where do they come from
scientists?