>both have SOME scientific basis. Race isn't clearly defined
>but there are genetic traits that are common to people with
>shared ancestry. For lack of a better term, that's race. If I
>need a bone marrow transplant, I won't be able to get it from
>a Korean.

agreed.

>While both race and gender are fluid, they're fluid in
>different ways. We all have biological parents of different
>genders

no. we all have bio parents of differing SEX. it is entirely possible for 2 persons who identify as women to produce a baby - the old fashioned way - as long as one of them produces sperm and has a penis (aka is biologically male) and the other has a vagina and at least one ovary that produces eggs and has a uterus, et al (aka is biologically female). i know of trans couples who have reproduced this way.

http://thechive.com/2014/08/14/transgender-couple-have-some-explaining-to-do-22-photos/