My book on Palaeolithic art considers scrapping a hypothesis about cave art's educational use, because some of its scenes "can't" have been observed or copied properly.
Why? Because animals that are "quite clearly male" are depicted trying to initiate sex with other males.
You obviously don't need observational skills to get your doctorate, anyway.
1) How heterosexist.
2) How divorced are we from the natural world nowadays??? This "fully heterosexual bison" dogma is one step away from the famous piece stating that "a cow has six sides - right, left, upper and below".