>> [...] Thee are two sexes, neither more nor less, and those sexes are readily identifiable by objective anatomical, physiological and genetic markers. “Gender,” on the other hand, is fluid and multiform: it’s a social construct. [...] Don’t say “gender” instead of “sex.” In the present hostile rhetorical environment, to focus on “gender” is to concede all important points to the genderqueers from the outset.
I would’ve said there are just two genders for the exact same reason you say there are just two sexes.
To abandon the word “gender” because of “genderqueers” is to concede that “gender” is “fluid” and “a social construct”. Gender isn’t fluid ... it isn’t a social construct. It means the same thing a “sex” — and to differentiate the two is to fall into the very trap you’re trying to avoid.
SnakeDoc
Only a handful of languages have gender classifications for only masculine or feminine (for example Spanish, Hebrew); many more have also a neuter grammatical gender (Polish, and the Scandinavian languages) and some have additional genders (noun forms) having to do with distinctions between living/nonliving, rank, formality, or role (Japanese.) Even the languages that have only masculine and feminine genders do not always connect them with sex(e.g. in Spanish "mano" is a "hand", but not necessarily a male hand, etc. etc.)
Thus gender and sex are not exact synonyms.
For this reason, the Oxford English Dictionary, way before the "genderqueers" began to impose their interpretation on things, recommended grammatical usage as the primary meaning of gender in English. As Fowler's 'Modern English Usage (1926) says, "Gender...is a grammatical term only. To talk of persons...of the masculine or feminine g[ender], meaning of the male or female sex, is either a jocularity (permissible or not according to context) or a blunder."
The word "sex" distinguishes between reproductively male and female entities,in all species which reproduce sexually, even plants. Thus organs like stigma, style, and ovary (female) and anther and filament (male) are organs of sex but not gender.
That is important, because (for instance medically) a change of external presentation (e.g. surgery) may be used to help a person cope with an "intergender" condition (a social or psychological dysfunction) but does not actually change one's sex.