[XAP]Bob wrote:Worth dropping this in...
Yes, it's amazing the lengths that people go to obfuscate and deny simple facts.
There were a remarkable number of strawmen and misleading claims there.
The Y chromosome is the male chromosome and it's really as simple as that. We have 22 pairs of identical chromosomes, and the 23rd is non-identical, with Y having evolved from X to signal male sex.
It really doesn't have another function. These are called sex chromosomes because they differ between sexes, because they are the only pair that are non-identical, and because the presence of the Y chromosome signals sex. Other sex chromosome systems in other organisms, such as the female chromosome being sex-determining in birds, or males having only one sex chromosome, are also sex chromosomes.
In an X0 system the X chromosome IS the sex chromosome because 2 Xs is female and 1 X is male. Thus an X0 bat species might have 17 identical pairs of chromosome and either 1 (male) or 2 identical (female) sex chromosomes.
The fact that the sex chromosome doesn't only determine sex and sex-related genes are found on other chromosomes doesn't change the fact that the sex chromosomes are the ones that differ between and determine sex, hence we call them sex chromosomes, unless we are disingenuous people trying to conflate politics with science.
Much of the rest of this talk was trying to exaggerate the importance of past scientific errors in order to push political points.
Sexual reproduction involves a binary set of female and male gametes meeting to produce a new organism. Male violence seems to be linked to testosterone, which is produced by testes, signalled for by the Y chromosome. That someone incorrectly thought the Y chromosome itself led to aggression doesn't change the fact that the Y chromosome does signal male sex, and male sex is linked to aggression.
Even a dog owner could see that castrating their dog reduces aggression.
Athletes with androgen insensitivity, testes and XY chromosomes ARE biologically male. They are ALSO female in the sense that we may perceive them as female, which is a word that meant something for millennia before we could analyse DNA, and find out that a barren woman was in some cases in fact biologically male. Androgen insensitivity is not something that can be measured exactly, and most athletes with androgen insensitivity get SOME benefit from testosterone, but they don't respond to it as well as normal males or females. However they are many times overrepresented in female sport, and this is because of their biological maleness. So to assert that the social sense in which someone who appears to be female but is biologically male, is female (which they are, throughout history), is necessarily the sense that we should adopt for sport is quite dishonest.
To further assert that someone who doesn't appear convincingly female, is biologically male, but has merely said 'I say I am female, therefore I am' following male puberty, and despite our eyes telling us otherwise, is in the sporting sense female is ludicrous, since sport is based on a strict biological division between males and females, or in some cases 'males under 50kg', 'males 50-60kg', etc. Because of the different levels of hormone produced in male and female gonads, a mediocre male is still stronger than an elite female, so any sporting spectacle that does not take into account specifically the sex steroids and their effects on the developing human body renders the division between male and female sporting categories pointless.
There might not be a fairness imperative that says we should prevent athletes who have always 'been' female while also being biologically males from competing in female sport, but that really would depend on the size of any advantage, amount of overrpresentation, etc. For example someone with a genetic disorder who 'is' female while being biologically male, but who is as fast as elite males probably should not be allowed to compete as female. However, mere overrepresentation of biologically male people with genetic disorders isn't necessarily disqualifying if they do not possess strength/speed BEYOND elite females.
That's different from people who merely assert their femaleness while having been aware from an early age of the fact of their biological male status, in that there doesn't seem to be a fairness issue that they must be allowed to compete in a division based on biology, not feelings.