First definition of man from OED entry: “A human being (irrespective of sex or age).
Man was considered until the 20th cent. to include women by implication, though referring primarily to males. It is now freq. understood to exclude women, and is therefore avoided by many people.”
Section of the etymology: “In all the Germanic languages the word had the two senses ‘human being’ and ‘adult male human being’, though exc. in English it has been mainly replaced in the former sense by a derivative (German Mensch, Dutch mens, Swedish människa, Danish menneske person, human being: compare mannish n.). In Old English the words distinctive of sex were wer [were n.1] and wīf [wife n.], wǣpmann [wapman n.] and wīfmann [woman n.]; both the masculine terms became obsolete by the end of the 13th cent., leaving English with no means of distinguishing the two major senses. The genderless uses of man to mean ‘human being’ or ‘person’ are now often objected to on the grounds that they depreciate women, and are frequently replaced by human, human being, or person.”
So the way I read it, maybe we start calling male human beings weremen!