Any biologists here?

[WTAFisthisshit]

Hi

I've lurked on Mumsnet for years and recently gravitated towards the feminist boards as it seemed to be only place where I found people with 'common sense' views.

You all seem to be very educated here so was wondering if someone could help explain to me what my daughter is currently being taught at uni.

She is studying psychology an is doing a biology module as part of it where she has been taught there are 8 different types of chromosome sex.

I was under the impression that xx = female and xy = male that there were rare instances of hermaphrodites and I was vaguely aware of xyy and xyyy which were still male but linked to violent offenders.

Does anybody know what this is and can explain it at a level that somebody with only secondary school science can understand and what the bloody hell it has to do with trans?

Thank you

Caster's AIS has been described as 4.5 (out of five) or some such. The claim is that the 'effective' testosterone is less than a natal woman, even if the actual level is much higher.

When Caster's testosterone is suppressed to (still very high) 10nmol/l levels, she is no longer competitive.

I am not convinced at all that it is possible to quantify this. Caster is to a significant extent male (male genotype, and other indicators)

I've always felt very sorry for Caster, but it's now clear that compassion for her is being abused

I think it is more likely that Caster Semenya has 5aRD (5alpha reductase deficiency). In this syndrome, the Y chromosome is present but incorrect development of the external genitals causes the male baby's sex to be misattributed at birth. Individuals with this usually end up with testosterone in the low normal male range. The person is biologically male with the advantages that would give in sport over females.

I'm not sure, BlindYeo, because the IOC have implied in the past that testosterone levels won't resolve the Caster issue. And that only makes sense if she has partial AIS.

I see your point Selma but testosterone levels wouldn't solve the issue of an athlete who has been through male type puberty with all the permanent advantages that bestows, so 5aRD still fits if the IOC said that.