PaulK writes:
Well I'd think that if there's a purpose to same-sex sexual attraction then it probably involves same-sex sexual activity - either as a part of the purpose or as a part of working out that purpose. It would be a little odd to intentionally motivate someone to engage in any activity without the intent that they should engage in that activity.
There may be an evolutionary advantage to having the %homosexuality rise under population pressure. This won't necessarily translate to those sub-populations with the highest pressure having the highest %, but overall there may be a correlation. When a species is selected to prevail to the next generation, the ability to respond to its own population demographics may give it a slight advantage.
But actually, in the case of homo sapiens, I think the % has been fairly uniform over the last 2 million or so years.
It also could be a residual archaic genetic attraction to all members of the species from the earlier non-hetero ancestor species that has faded and leveled off to its current % today.
It certainly is natural.
- xongsmith, 5.7d