No idea what your point is here. You seem to be defining "natural" as "found in nature" (ie in species other than man??). Your original question implies that homosexuality is "unnatural". Now that you see that it is not, your argument seems to switch over to "OK, but humans should 'know better' because of their increased brain power." Whether we're any brighter than dolphins or chimps is debatable, but we all come from the same evolutionary tree, so why should what is "natural" for many species be "unnatural" for humans?