Eligibility for women's Olympic events should be based in part on a genetic test

By all accounts Imane Khelif is a woman, but the fact she is a woman is not sufficient to guarantee participation in women's Olympic events. In my opinion, eligibility should also be based in part on a genetic test, namely whether the athlete is XX or XY.

As you know from high school biology, human biological sex is typically determined by the absence or presence of the Y chromosome.  Females possess 2 X chromosomes (XX) and males possess an X chromosome and a Y chromosome (XY). The Y chromosome contains the SRY gene (Wikipedia) that is a master transcriptional regulator responsible for the development of the testes: "SRY initiates testis differentiation by activating male-specific transcription factors that allow these bipotential cells to differentiate and proliferate." The testes in turn produce testosterone which stimulates protein production in muscle cells leading to increased muscle mass especially in combination with intensive training. This is why doping with anabolic steroids (testosterone analogs) is such a big deal in competitive athletics.

In a simple world, based on the genetic test, anyone who is XY would not be allowed to compete in women's Olympic events. But life is more complicated. For example, one can be XY but phenotypically female if the SRY gene has been inactivated by mutation. 

Imane Khelif and Lin Yu-ting were not allowed to compete in the IBA Women’s World Boxing Championships 2023 based on a genetic test. We do not know the results of this test, and so it is impossible to ascertain whether this ruling was justified. Plus, as mentioned above, there are a lot of subtleties with respect to interpreting the genetic test.

Overall, I view this controversy as being vastly overblown by conservative culture warriors, and a red herring compared to the real problem in sports which has been and still is doping. At the highest levels of athletic competition, a tiny sliver of an advantage can be the difference between winning and losing (e.g. 100M men's sprint final), and doping can literally have an oversized impact (e.g. Mark McGwire, Sammy Sosa, and Barry Bonds) which is why athletes continue to dope.

In summary I would say that gender is not based on a genetic test, but eligibility for women's Olympic events should be based in part on a genetic test.