I don’t disagree about skeletal differences, but cardiovascular performance capability is reduced after trans women have been on hormones for several years to more align with cis women. Lia Thomas is a bad example in many ways because her height is unusual, even among male competitive swimmers. Having said this, the dominance people like to point to is merely in one event, where she ranked first during this past swimming season. In the other events in which she competed, she ranked fifth and seventh. This would not have put her on the podium in either one of them.
You also should be aware that the competition among Ivy League swimmers over the past several years is considered to be subpar. This also comes into play. Lia’s apparent “dominance“ has as much to do with the lack of quality competition as any inherent genetic advantage. It is more realistic to compare her best performances against those of the best women swimmers. In this regard, she is rather average. She is not taking a spot from cis women swimmers.
As to your suggestion that skeletal structure is fixed and gives trans women an advantage, this is not necessarily true. There is a wide variance in the structure between many different types of men and women and a lot of crossover. We think of the classic male as having an inverted pyramid or mesomorphic body structure. Many men and women (including myself) are more ectomorphic—relatively tall and slender with slender arms and legs (I am 6’ 43,36,44.) The only women who arguably have a skeletal disadvantage are those with the classic pear structure of wide hips and narrow shoulders. However very few, if any, of the women of this body type are competitive athletes.
As Bruce Kidd, a former Olympic racer, professor at the University of Toronto and long time gender equity in sports advocate has noted, most superior women athletes have natural anatomical advantages. Most of them are taller or have a longer reach or more fast twitch muscle fibers. We do not penalize them for these genetic advantages. Rather, we celebrate their ability.
Finally trans women have competed in women’s sports for at least 40 or 50 years. There has never been a single instance of any trans woman being dominant in any given sport. If the advantage were really that great, you would expect trans women to be rewriting the record books. They are not. The population of trans women is very small compared to the overall female population and the number of trans women competing in women’s sports is even smaller. The assumption that there is a major pending problem is strictly overblown fear about something which does not exist and has never happened.
A bigger problem is women who have DSD, and naturally high testosterone levels. Look at Caster Semenya. These women who look like women and are considered women have a natural advantage which currently requires them to reduce their testosterone levels to be allowed to continue to compete. These are actually the individuals rewriting the women’s record books , not trans women. If you are worried about competitive advantage, you need to focus on the real problem which is testosterone, not chromosomes.
You talked about the doping problem. This was a major problem in the late 60s and early 70s in the former Soviet Union. What gave certain women a performance advantage was testosterone, not their genes. Testosterone is now and has always been the issue. It is suppressing the effects of testosterone that evens the playing field for trans women athletes once they have been on hormones for several years.
