Can anyone with a biologist background explain this tweet to me

[BluesandClues]

This tweet seems to get trotted out a lot by people on Twitter suggested that biologically sex is more complicated than first thought.

I will admit to be sceptical, but I’ve not seen it refuted.

twitter.com/RebeccaRHelm/status/1207834357639139328?s=20&t=nSijAQNWTv2y4WzrjikNbQ

It might be helpful if you gave an overview of just how far and wide you cast your net to be so sure that it's not been refuted.

Maybe a few names and search terms would help us to understand where you looked.

Read Emma Hilton's tweets - she's fondofbeetles on Twitter. Search for her name and DSD

The faux friendly neighbourhood biologist is twisting facts to suit her agenda. Humans are a dimorphic species. A small number of people didn't develop properly. That doesn't make sex complicated any more than the people born with a missing limb should make us question if we really are bipeds.

Sex is not complicated at all, it just refers to your reproductive class, and we have 2 of those, one makes little gametes and one makes big gametes. Sex can only be 'complicated' if there are more gametes...

Not a biologist, but I don't think any of the 'look how complicated it is/how many edge cases there are' is remotely relevant to the question, "Is this physically normal male person actually female (or vice versa) if they have (unverifiable, internal) feelings that they are?"

It's just distraction.

If it was really "complicated" and not simply male +female, why would humans keep reproducing?

@EmbarrassingHadrosaurus i was trying to go through the replies and couldn’t see anything immediately apparent.

I thought I’d ask here, and see if anyone had seen any reply.

@Clymene oh cool, thanks for that.

Here's an earlier thread about that tweet.

www.mumsnet.com/talk/womens_rights/3793311-biologists-take-on-sex-seen-in-fab

You could also read this:
genderarguments.com/openletterbiologicalsex/

I have studied bits of human biology, I’m no biologist. But I can read a research paper and mostly make sense of it.

Honestly, was wondering if I’d missed something along the way. The fact that she’s an ocean biologist made me pause.

Oh @OldCrone thank you!! Will go and read now.

Thanks.

A few sources:
In humans sex is binary and immutable
perspectives on sex and gender
science, sport and sex
considering sex as a biological variable

The last reference is to an academic article about many issues but as part of those issues it has a very thorough section on the definition of biological sex and all the complications around that definiton.

Not my area of biology but it is true that SRY is the gene which switches on all the other genes which leads to the body developing male sex organs. If it is lost from a Y chromosome then the person will develop as a female with an XY karyotype. If it translocates to another chromosome then someone with an XX karyotype would develop male sex organs. There are only a few other genes on the Y chromosome and I can't remember if they are essential for fertility (they definitely aren't for survival or women wouldn't exist), so it may be that an XX female with an SRY translocation is sterile.

I don't know offhand what the hormone level ranges are for men and women, so can't comment on whether women and men can overlap.

For sure it is a complicated subject. In other species sex determination can happen in other ways. For example turtles and crocodiles use the temperature at which the eggs are incubated at to determine whether they develop into males or females. At either extreme of the viable temperature range for egg development you get vastly more of one sex than the other. In the middle you get more of a 50:50 ratio. A lot of social insects like bees have unfertilised eggs become the female worker bees and fertilised eggs as the male drones. So a single set of chromosomes = female, double = male. I think that some flies may even have XY females and XX males (25 years since I studied that though, so I may have made that up by now.)

Nemo confused her I expect.

I don't think the anti-GC argument comes from there, to be honest. Yes, to be sure, there are many shades between biologically female and biologically male. Yet, most people are grouped at the poles.

The anti-GC, pro-trans argument comes from a point of kindness and pragmatism. That is, it recognises that, transwomen suffer, and their suffering is a great deal more than the suffering of those who, collectively, claim to be 'oppressed' by transwomen. Most of those haven't ever been affected by a transwomen. A large number haven't even seen a transwoman, and known her as such.

We are in the strange - some would say outright perverse - situation of people arguing, ferociously, that the tiny few transwomen there are threaten us, in our toilets, changing rooms, and in our sports, because we're so fragile as natal women, and those possessing (or who once possessed) penises and testicles, are so powerful.

Go figure. I think, perhaps, we haven't seen off these transwomen and their supporters because we haven't burst into tears and lamented about how threatening they are to us ... despite our outnumbering them by 80 or more to one ... and that's why the powers-that-be haven't listened to us.

We need to cry some more. That's the answer!

If we took that seriously we might think hardly anyone was male or female and that would end the dairy industry since we'd have to do a full DNA Sequencing before we could milk a cow. 😂

Perhaps we should drag these people down to the farm for some real life experience. We could let them try milking a bull.

"it's ok it identifies as a cow" we'll tell them.

I came across that a while ago and went and looked up SRY translocations on Google.

Honestly, ten minutes on the internet and you can work out that she's talking about DSDs and muddying the waters. I don't think that I need a DNA test to establish that I'm XX, having menstruated, conceived several times, miscarried, given birth, lactated and gone through the menopause.

Plus her patronising opening sets my teeth on edge.

"The anti-GC, pro-trans argument comes from a point of kindness"

Funny I was just looking at a trans T-shirt with sharp knives on it for slicing open TERFs. In a kind way of course.

If you want one i can give you a link

Oh my god. Penis and testicles again! And snark and derision about women’s comments.

Nothing new in your posts Ides and they simply remain unconvincing except of your own peculiar prejudices.

Ew, 'friendly neighbourhood biologist here, folks!" What's with the weird Disney character language? As for sex being complicated, you could apply this argument to any other biological concept. What determines or causes 'age' in humans? Is it our physical appearance? Genetics? Health of organs? What about people who suffer from progeria, which means they are young in years but have an elderly body? What about people with syndrome X, which means they can be old in years but have the body of a toddler? But even though age is complex, it doesn't mean that a 50 year old, with no disease or condition, can just declare they are really 5 years old.

The same goes for sex. Trans people are not claiming to suffer from a DSD. Trans women are straightforwardly males. They have male gametes, male reproductive organs, male chromosomes etc. And their claim is their inner identity, their belief or feeling or self declaration that they are a woman trumps their biology. The complexity of biological sex is a complete red herring. Suppose biological sex was completely simple, with no disorders or edge cases. Do you really suppose that trans women would shrug and say 'oh I guess I really am a male after all". Of course not.

You’re talking about a DSD. In other words, something has gone wrong very early on in the gestational process. The foetus will still be either male or female. But with a difference of their sex development.

.

So I'm one of those people with somewhat mixed up genes 🤷🏻‍♀️ go me...

My unique karyotyping is

46,XX, t(3;8)(q25.3;q13)

I have a balanced translocation.

I'm still XX though and am fertile(ISH) 😂 I have one living offspring who does not have the translocation and I have had 16 miscarriages. My parents don't have the translocation and neither does my sibling.

Just because your DNA can get a bit muddled up on occasion doest suddenly mean that for the majority of the global population that biological sex is a "grey area" .

There are exceptions where you can have issues with the sex chromosomes but on the whole people should stop exploiting such people to perpetuate a myth and a belief system.

Just bringing it back to prevalence of other congenital conditions and limbs again.

The prevalence of people with congenital limb disorders is about 1 in 1,900.

The prevalence of people with disorders of sexual development is about 1 in 5,500.

So there are many more people with a limb that hasn't developed properly in the uterus. We don't see this as some kind of evidence of different limb development, we see it for what it is - sometimes things get messed up.

And apart from anything else, none of this has anything to do with transgender issues. DSDs are only relevant to women when men with DSDs are allowed to compete in women's sport so there is an overlap there with transwomen. Otherwise, it's a on unrelated discussion

@WeeBisom Excellent post. Especially this bit
As for sex being complicated, you could apply this argument to any other biological concept. What determines or causes 'age' in humans? Is it our physical appearance? Genetics? Health of organs? What about people who suffer from progeria, which means they are young in years but have an elderly body? What about people with syndrome X, which means they can be old in years but have the body of a toddler? But even though age is complex, it doesn't mean that a 50 year old, with no disease or condition, can just declare they are really 5 years old.

Sex refers to your reproductive class. Female > large gametes (in humans, ova); male > small gametes (in humans, sperm).