While everyone has been binging on the Winter Olympics the past two weeks, I’ve had my eye on mixed martial arts, one of my favorite sports. Last week, it was announced that Anne Veriato, a transgender female MMA fighter, will be fighting a male opponent, Railson Paixao, on March 10 in Manaus, Brazil. “It’s only fair to fight men,” 21-year-old Veriato told MMA Fighting. “If I beat men my entire career, I can still beat them despite the hormone process […] I don’t think it’s fair to fight women.”

This may catch you by surprise, considering how Veriato’s outlook is in stark opposition to the precedent set five years ago by Fallon Fox, MMA’s first openly transgender fighter. Fans who followed the controversy back then may remember that Fox, who was born male and had transitioned to female, didn’t initially disclose this information to the athletic commissions or her opponents. After reporters caught wind of it, Fox outed herself, sparking a whirlwind of outrage.

Fox was, however, allowed to continue competing against female fighters. Further backlash ensued after a match in 2014 in which she gave her opponent, Tamikka Brents, a concussion and broken eye socket that required seven staples. In a post-fight interview with Whoa TV, Brents said, “I’ve never felt so overpowered ever in my life.”

Whether or not transgender athletes should be allowed to compete against opponents who do not share their birth sex remains a contentious issue today. The conversation has become even murkier because epithets like “transphobic” frequently get thrown around to describe anyone who disagrees.

This is because, when it comes to gender identity, self-determination overrides all else. We see this in the growing adoption of labels like “non-binary” and “agender,” and any opinion going against it gets thrown into a pit of flames. If you recall, public figures like Joe Rogan and Ronda Rousey faced ugly allegations of “ignorance and bigotry” and “transmisogyny” for saying that transgender women should not be fighting in the women’s division.

Scientifically speaking, there are differences between women who were born as women and women who are transgender. My position is that gender dysphoria is indeed real, and science has shown that transitioning can be beneficial for gender dysphoric adults. I also wholeheartedly believe that transgender individuals should be afforded the same rights and opportunities as everyone else, including when competing in professional sports. But it isn’t unreasonable to question whether someone who identifies as the opposite sex still possesses physical traits characteristic of their birth sex.

This isn’t a trivial matter; in the case of competitive fighting, these differences can provide an unfair advantage over one’s opponent. It’s an uncomfortable discussion because it acknowledges that transgender women are on some level fundamentally different from women who were born with female genitalia. Using these physical differences as a guide for decisions about which sports division they should compete in feels like we are telling them which gender they really are.

There has been a movement as of late to pretend that women and men are identical in the name of gender equality. This growing trend of denigrating biology goes beyond denying sex differences in the brain to, incredibly, denying differences in physical characteristics like strength as well. You might remember how people got upset last year after John McEnroe suggested that female tennis players may not share the same playing abilities as their male counterparts.

And earlier this year, a study demonstrating that women are able to survive for longer than men under extreme environmental conditions, like epidemics and famines, was somehow interpreted as showing that “women really are the stronger sex.”

Putting these ludicrous assertions aside, the reality is that, regardless of how a person identifies their gender, someone who undergoes male puberty will be on average physically larger and stronger than someone who undergoes female puberty. Of course, there is a great deal of variation among men and women, and some women do happen to have a natural advantage in strength over men.

But more generally, puberty is associated with sex differences in musculature and bone density, with men having higher muscle and bone masses than women. Considering that estrogen—not testosterone—causes bone growth, even if a transgender woman takes hormonal blockers and undergoes an orchiectomy (removal of the testes), undergoing estrogen therapy can compensate for the presumed loss in bone density.

Per the Association for Boxing Commissions’ policy, in order to fight against women, male-to-female transgender athletes who have undergone male puberty must have had gender reassignment surgery and be on hormonal therapy for a minimum of two years post-surgery. This is viewed as the minimum amount of time needed to offset any physical advantages associated with having been male at one time.

One of the reasons Veriato’s story has gained media attention is due to her going against the grain and embracing that she is different. This touches on the larger discussion about whether transgender women are women, full stop. An on-going battle continues to rage between transgender activists and radical feminists, who believe transwomen were born male and can never truly understand what it means to be a woman (hence trans activists’ use of the term, “TERF,” to describe “trans-exclusionary radical feminists”).

Radical feminists argue in defense of women’s spaces being allocated only to women who were born female, including bathrooms and locker rooms, out of concern for women’s and girls’ safety. But from the perspective of trans women, being relegated to men’s spaces can exacerbate feelings of gender dysphoria, and they, too, can find their safety in jeopardy because some men don’t take kindly to them being there.

There are no easy answers, but banning a topic from discussion and shaming people for calling particular narratives into question only makes it more difficult for true understanding to be reached. Transgender people deserve to be treated with respect, and this includes within the world of MMA fighting. But acknowledging these rights aren’t in conflict with accepting biological truths.

Debra W. Soh holds a PhD in sexual neuroscience research from York University and writes about the science and politics of sex. Her writing has appeared in Harper’s, the Wall Street Journal, the Los Angeles Times, the Globe and Mail and many others. Follow her and her writing: @DrDebraSoh.