Epigenetics.

Not just the genes themselves, but how the genes express themselves.

Fertile field. Explains a lot.

But no matter how you try to slice it, sexual orientation is STILL not a matter of choice.

Look it up, Goofus. I want to see what kind of a hash you manage to make out of that.

Don Firth

P. S. I love science! It can get complicated, but it's so clean.