Gender is a similarity cluster or conceptual model used to simplify explanations of a number of biological phenomena. As these phenomena underlie a great deal of biology is often taken as being themselves fundamental to how biology operates, but this view (known as gender essentialism) is mistaken.
(For a solid introduction to the science around gender, see gender/101 on HTYP.)
- Conservapedia as of 2017-08-23 redirects to "Sex" and affirms the gender essentialism position: "Sex is the attribute of being either male or female..."
- The same article defines "gender" as "what society expects of persons of different sexes", affirming the gender fundamentalist position.