> But these are edge cases that are almost always irrelevant.

More than 99% of atoms are either Hydrogen or Helium, all other proton configurations are edge cases that are almost always irrelevant.

As with anything, you have to determine the question you are actually asking and the context you are asking it in before you can decide whether or not edge cases are relevant. Are you engineering for a satellite? You better consider the possibility of cosmic rays!

Also intersex people are astronomically more common than bit flips on earth and people with sex hormone imbalances are even more common than that.

Are humans a bipedal species?

Just asking, because some people are born with a different number of legs.

Informally speaking? yeah sure. Discussing the relative benefits of natural forms of locomotion? absolutely. Designing the entrance of a building? I should consider that not everyone is bipedal.

I would submit that the question if humans as a species are bipedal is not concerned with the question if any individual specimen happens to have two legs.

(This is not meant to imply that no consideration should be given to the exceptions, which quite reasonably it clearly is.)

I agree which is why I phrased my answer the way I did (apologies that I wasn't very clear about that), but I don't think the claim is really analogous to "2 sexes, male and female. Simple and true." (not that you claimed that, just what someone above us said). The equivalent claim would be something like "humans are a sexually dimorphic species" which I think is of course true.

All to say, I don't really care much about these claims in isolation, I care when someone says e.g. "there are two sexes, so we shouldn't let trans people transition". Those conversations are a context where edge cases, caveats, and complexities all play a huge role.

Agreed.

>But these are edge cases that are almost always irrelevant.

Which is why authoritarians choose 'them' groups that are small and mostly powerless to demonize and exterminite first.