okay - basic biology question...

[loveyouradvice]

Am I right in thinking that from the very first second ie a one cell embryo they are either XX or XY?

Interesting discussion at lunch with well=informed woman who was quite convinced by the hormone washes determining sex later on in pregnancy.

Sorry this is biology 101 but I just needed to check...

I glanced at that Claire ainsworth article in Scientific American. The facts don't seem wrong on a quick scan SRY exists, mosaicism exists, etc but drawing from that the conclusion that 2 sexes is "overly simplistic" is doublespeak.

People are going to think, if they have no science background, that she means humans. It's nonsense for humans. There's nothing new in her summary that hasn't been known for decade(s?). Humans have one of the most complex, constrained embryological developmental pathways of any organism. Way more so than mice, for instance. Mammals generally have very rigid developmental pathways compared to other parts of the tree of life. E.g. alligator sex depending on temperature. In some fish, if I remember right, it depends on nutrition.

When you go further afield, say to fungi, it gets really interesting. Some of them have mating strains, not just two, but dozens. I think I remember hearing about hundreds. So strain A pairs with B, C, and D, but not E through Q. L pairs only with B. B pairs with A, L, Q, and Z. And so on, through a dizzying kaleidoscope of combinations. (I'm making the example up, just to give the idea.)

But if you were a science journalist, like Ainsworth, and you wrote a somewhat breathless article about fungi and left the impression that hoo-boy! discoveries about humans are just around the corner, it would be less than honest. She talks about mice, not fungi, so she's a bit closer to home, but her ooh-looky-here tone still bothers me.

They're are very rare instances where XXY, XYY or XXX occur, but they aren't usually noticeable unless you know what to look for and the majority of people with those combinations go undiagnosed.

totally misses point of thread

There are*

Since the case of the woman who’s body contains absorbed fragments of her dead brother’s DNA keeps coming up I’d like to ask why TRAs think this brings binary sex into question?

If you think about it the idea of someone having two genomes - albeit one overwhelmingly dominant - brings into question the nature of individual identity rather than merely a sex binary. If our genome is our genetic blueprint then having fragments of another genome tells us we can have the blueprint of more than one person.

This is a far deeper question than sex - so why do TRAs stop there? Why cling to raising doubts about biological sex when someone could far more interestingly have fragments of another person’s DNA in their brain?

People also carry more bacterial cells than human cells: ten times as many, in fact. There are approximately 500 species living in your gut - and they’re not all parasites: without many of them we couldn’t digest food. Some aid in immunity and the development of gut-associated lymphoid tissues. The absence of some gut bacteria may be linked to autism.

These bacteria are part of you. Without them you would die. And since they outnumber human cells we could say a person is a complex ecosystem of bacteria as much as we are a ‘human’ being. So again this raises philosophical questions about what it is to be ‘human’ when your body contains more non-human cells than human; and what it is to be an ‘individual’ when you are, in a sense, a colony of millions.

And if you look at human DNA itself, it’s full of harmless fragments of dead viruses that have been picked up over millions of years and passed down. Are these part of you? If they could be cleaned up with some kind of antivirus technology would what remains still be you?

TL;DR: Biology raises fascinating philosophical questions about the nature of the individual.

If your only interest in the subject is in how it can excuse you thrashing women in sport then you have no sense of wonder.

Brilliant post aspie

Here’s another example of the ‘Whats In it for trans?’ approach to science.

We’ve frequently seen a study cited in which a male mouse nucleus has been implanted in a mouse ova and the ova fertilised with a mouse sperm so that baby mice were born to two ‘fathers’.

This has been referenced endlessly in response to the point that women can gestate and transwomen cannot. It seems that many transwomen are under the impression that this research will mean that one day carry children too; or even that women will eventually become redundant.

Except that’s not what the research shows. More to the point, that’s not what the research is for.

The research isn’t directed towards helping transwomen conceive. It’s directed at studying a process called genetic imprinting.

Certain genes are marked - or imprinted - in such a way that they are always inherited from the mother or the father. If you have a sperm and an egg that both contain genetic material from a male mouse you have two sets of paternally imprinted genes and that would normally make the embryo unviable so the scientists have to knock out one set of these imprinted genes.

And that’s what this research is about: studying how imprinted genes influence embryo development, and developing techniques to knock out particular imprinted genes that cause abnormalities such as Prader-Willi and Angelman syndromes, some breast cancers and diabetes.

It’s not about transwomen at all. Nobody is pissing away millions of dollars of research money in the hope of ‘curing’ transwomen of the inability to get pregnant because that isn’t a disorder, it’s simply a consequence of not being female.

Thanks everyone for the info on the article. Wish I could make the person who posted it on Facebook understand.

aspie is correct -it’s not at all what the research is FOR.

Humans also have much less ‘forgiving’ imprinting when it comes to embryos - what you can get away with in a mouse can be catastrophic for a human. Mouse embryos are a useful model for some things but not all - this just shows how little understanding of the science they have (the TRa, not the mice...)

I was going to mention bacteria- I see aspie covered that

The misunderstanding of science is bad enough. The deliberate twisting of it by TRAs I find very concerning.

You can make all the virgin birth mice you like - you still can’t do it in a human. And if you could, the ethics of doing it just to make a man give birth are abhorrent

deepwatersolo

I find all tgis fascinating and so sad That for so long some of these conditions were very hidden.

"That may in the extremest case mean the body's cells are XY, but the organism develops a vagina and the baby looks like a girl (Swyer Syndrome). This condition leads to infertility. There are no functioning ovaries."

With Swyer Syndrome it is incredibly rare but some females born XY do have a uterus.

genetics.thetech.org/ask/ask352

JamPasty

"Can I get people's take on this article please? It pings my bullshitometer, but I know bugger all about development biology, so it could be 100% kosher."

www.scientificamerican.com/article/sex-redefined-the-idea-of-2-sexes-is-overly-simplistic1/

Actually think it is not just talking about intersex but mixing in other info for big effect.

But this is true as far as I know ...

"A study in 1996 recorded women with fetal cells in their blood as many as 27 years after giving birth; another found that maternal cells remain in children up to adulthood. This type of work has further blurred the sex divide, because it means that men often carry cells from their mothers, and women who have been pregnant with a male fetus can carry a smattering of its discarded cells."

To me it says to me how amazing women's bodies are at growing humans, nothing more!

I believe it may even be true of people who have had sex, that DNA stays around. Maybe even we can pick up DNA from others onto our bodies in other ways, it doesn't mean we are neither male nor female!

I think it’s fair to say that there’s a simple answer to the question Is sex is binary (yes) and a more complicated answer (yes, because...)

The yes, because answer is more interesting but really only adds an explanation to something most people know already. If you aren’t comfortable sharing your space you shouldn’t have to cite peer-reviewed papers on why not.

If you aren’t comfortable sharing your space you shouldn’t have to cite peer-reviewed papers on why not

Bloody well said!

In almost every case, yes. The prevelance of intersex conditions is disputed; estimates run between 0.1% and 2% of the population based on metaanalysis of dat since 1955 here.

Suggestions that humans aren't fundamentally dimorphic, or that sex is not a real category are driven by ideology, and usually devolve into post-modern critiques of language "What is a chair, anyway?"

Yes I carry a "smattering" of cells containing XY chromosomes because of the 4 male children I gestated, but these will be a tiny, tiny fraction of my total DNA, are not something I was born with or had in me for the first 32 years of my life, i.e.way after I was well and truly socialized as a girl, not to mention biologically female as I had already developed secondary sex characteristics, reached puberty and started menstruating by then, plus they will be in my bloodstream, not in any of my body tissues or in my brain as there is no way for them to intrgrate with my cells. So that in no way makes me anything other than female.

One of the X chromosomes women carry came from their Dad, that doesn't in any way make them male.

Baloney.