we are led in the vernacular to think of sex as fixed phenotype. however, the concept of sex refers to two things: phenotype *and* the processes that regulate that phenotype. change over time (sex differentiation as organismic growth) is why sex is a concept that indexes change. https://twitter.com/gp_jls/status/1391837603251556354

sex is a conceptual approximation that tries to describe both metabolic self-regulation *and* heredity/reproduction, which is why it’s so confusing and easy to be reductionist about it. as my book details, this tension has frustrated the life sciences for a century.

there has never been a scientific proof for binary sex, or the etiology of sex phenotype or gender identity. (and there never will be because the concepts are very simplistic in comparison to human variation.) chapters 1-3 of my book are good primers.

sex is not a description of fixity (male or female); it’s a description of a field of living, organic form that is animated by change in form over time. “male and female” are concepts we have (poorly) applied to phenomena that obviously exceed them.

this is an elementary insight in feminist science studies, but interestingly, it’s also a consensus view in the life sciences, though it long pained them to admit the conclusions of their own data.

I say all this not because I think feminist, queer, trans and intersex people need to appeal to science, but because we suffer from weak vernacular concepts of sex used to appeal to nature to reify social hierarchies.

eg until the 1960s, the consensus view in biology and medicine was that no one was really male or female, but rather a composite built out of the human species’ natural “bi-sexuality” (we all start out with the capacity to be any sex). but that was not a good era for trans folks!

the point is rather that our epistemology of sex is just as malleable as what it purports to describe. and anti-trans appeals to nature or science have nothing to stand on other than prejudice.