I found this fascinating study that suggests chimerism is much more prevelent

[Claire Oh Nette]

1. Absorbed Twins?

If twins fail to develop, one may absorb the other in the womb. It's not uncommon. When coupled with the number of pregnancies that don't develop to term, or the "late periods" before a woman realizes she's pregnant, it's entirely possible there are more chimeras than we knew, and that this might account for the increased prevalence for homosexuality among adopted adults. High stress pregnancies, and possible chimeras from twins failing to thrive in the stressed out womb.

Sexuality and gender identity seem to be fluid and fall acros a spectrum. Could simply be LGBTQ folk are just god's plan for population control. Could be without social taboos and sexual repression, everyone would claim bisexuality under teh right circumstance.

Interesting article.