You have a bit of a contradiction going on here. Your first sentence states that you think anthropology isn't science and your last sentence cites it as an example of a "biological scientific field". The part of forensics that deals with human bodies and especially racial classification is called forensic anthropology.

Now, the relationship between academic and forensic anthropologists is pretty fraught, but not because the regular anthropologists are out there inventing new genders all the time. It's because forensic anthropology uses outdated methodologies widely considered unscientific, including racial identifications. That's why the US National Academy called for forensic science reform back in 2009 and why you still get debates like this between academics and forensic anthropologists: https://doi.org/10.1111/1556-4029.14513