Y chromosome

Mary Daly wrote about this in her book Gyn/Ecology. She wrote how interesting it was that men had a vested interest in making sure this didn't become public knowledge.

Why - will there be riots ?

Mary Daly wrote about this in her book Gyn/Ecology. She wrote how interesting it was that men had a vested interest in making sure this didn't become public knowledge.

So all I'm saying is, people disputing the science, saying "streamlined" instead of "degraded" might have been affected by this interest

It is not being degraded. It is being streamlined

Not what I've read

Well, species that rely on asexual reproduction can do very well indeed. Binary fission in bacteria and all that. Lots of plants manage quite well, and even manage sympatric speciation following on from polyploidy.

But we aren't plants, or clown fish.

And any mutation that affects the SRY region negatively simply isn't going to be selected for. Given that we don't reproduce asexually. We can't do what plants do. So any negative effect will simply not be passed on.

Oo, perhaps elimination of the SRY gene is what happened to fertility in the Handmaids tale...?

Paleobiology has demonstrated good evidence that species which reproduce parthogenetically don't last long. It seems that sexual reproduction is required to keep evolution ticking along. So, if humans are to keep going, we need women but we also need men.

The Y chromosome is simply the carrier for the SRY gene, which is the switch which turns a developing mammalian foetus from a female trajectory to a male one. Some mammals have apparently done away with the Y chromosome, but have actually moved the SRY gene to another chromosome. The erosion of the human Y over time chromosome has almost certainly stopped.

Now, maybe with our big brains we can interfere with all of this, but that is another discussion.

Just wanted to say thanks to those explaining the science of the X and Y chromosomes on this thread. I'd previously only read the "Y is a degenderated X' argument in the past and I don't have a great grounding in biology so it's fantastic to have it clearly explained by the likes of EndoplasmicReticulum and AlwaysComingHome.

What Igneococcus says is correct. Women have two X chromosomes in each cell, men have one X and one Y, but (pseudoautosomal region excluded) one X is inactivated in each cell.

A gene is a DNA sequence that codes for a protein so it’s debatable whether you can refer to a sequence on an inactivated chromosome as a ‘gene’ at all. The genes on the active X are coding for the proteins.

A man doesn’t lack DNA found on the X chromosome. If he did he couldn’t produce sperm cells that contain the X, and he couldn’t father a girl.

The default developmental phenotype is female. The SRY gene over-rides this default developmental route. The Y chromosome is not some feeble half-X; it is a pared down delivery mechanism for male sexual development.

It does not carry superfluous genes because if it did these would only pass down the male germ line.

It is not being degraded. It is being streamlined. Evolution isn’t going to eliminate it because natural selection acts upon mutations that can be passed down. A mutation such as the deletion of the SRY gene isn’t going to be selected for because the SRY gene is necessary for reproduction.

I have had this same conversation with TRAs who insist that intersex conditions that can cause infertility are ‘part of evolution.’

Blog post if anyone is interested:
www.nature.com/news/the-human-y-chromosome-is-here-to-stay-1.10082#b1

It can be tempting to look at an image like this one and think it shows that "The Y is basically the X with bits missing" but that's not the case. The Y has different genes from the X.
Yes, it is true that the Y has fewer genes than the X, and yes it has lost some over evolutionary history.
Most of it (95%) can now no longer recombine (swap bits) with the X.
It is still not "basically the X with bits missing."

Men have all the genes on the X chromosome too, they just have one copy of each but then women make Barr bodies which effectively inactivates one set of their X-chromosomal genes.
Maybe I need to read the other thread, I think I'm missing the point that is trying to be made,

Always thank you for clarity. Science is so soothing.

Crossing over (a source of genetic reshuffling) occurs between the X and Y chromosomes in the pseudoautisomal region during division.

To describe the Y chromosome as being empty is wildly inaccurate since it holds the SRY region which has, as we know, massive effects on development.

Anyone interested in the Y chromosome should the Steve Jones book on it.

Waiting now for someone to cite the mouse-with-two-mums article that TRAs are so fond of, because that the direction this is heading.

Facts from the article, feel free to dispute if you can:

"the Y chromosome has degenerated rapidly, leaving females with two perfectly normal X chromosomes, but males with an X and a shrivelled Y. If the same rate of degeneration continues, the Y chromosome has just 4.6m years left before it disappears completely.

Well, that’s clearly bollocks.

How exactly would natural selection favour the elimination of the SRY gene?

The Y chromosome has been paired down because it is not necessary to duplicate the genes males already inherit from their mothers but it can’t degrade beyond the point that it doesn’t have the genes essential for reproduction.

No SRY, no reproduction. No reproduction, no evolution.

The rest of the Y chromosome is a wasteland of meaningless repetition.

Look who’s talking.

I think this is the topic women are really not allowed to talk about

If a day has gone by since I joined this forum in which we didn’t discuss Y chromosomes, I must have missed it.

The difference between XX and XY is the molecular basis of women’s oppression.

Still doing it I see Roses.

There's an article there from the Smithsonian magazine saying pretty much the same thing. Are you able to engage with that?

m.youtube.com/watch?v=nQcgD5DpVlQ

Lots of fun facts about the Y chromosome on this Ted talk:

Not allowed to talk about?
Why? Sorry, but if you come across as talking utter bollocks you're going to get questioned like someone did to your post on the other thread.
All I said was any Joe Bloggs could put together a WordPress article, which they can.

Facts from the article, feel free to dispute if you can:

"the Y chromosome has degenerated rapidly, leaving females with two perfectly normal X chromosomes, but males with an X and a shrivelled Y. If the same rate of degeneration continues, the Y chromosome has just 4.6m years left before it disappears completely. This may sound like a long time, but it isn’t when you consider that life has existed on Earth for 3.5 billion years.

The Y chromosome hasn’t always been like this. If we rewind the clock to 166m years ago, to the very first mammals, the story was completely different. The early “proto-Y” chromosome was originally the same size as the X chromosome and contained all the same genes. However, Y chromosomes have a fundamental flaw. Unlike all other chromosomes, which we have two copies of in each of our cells, Y chromosomes are only ever present as a single copy, passed from fathers to their sons.

This means that genes on the Y chromosome cannot undergo genetic recombination, the “shuffling” of genes that occurs in each generation which helps to eliminate damaging gene mutations. Deprived of the benefits of recombination, Y chromosomal genes degenerate over time and are eventually lost from the genome."

"shrivelled" - oh dear

It’s not the number of genes that matter, it’s what they do. A single gene is the difference between having, or not having, cystic fibrosis, sickle cell disease, Fragile X syndrome, muscular dystrophy, or Huntington disease.

A Y chromosome isn’t an X with a bit missing. It has the sex determining gene. The SRY has profound effect on male development. It takes the Male down a completely different developmental pathway. We talk about that every day on this forum. It’s why women’s sport is going to go down the toilet if biological men are allowed to compete. It’s not some inconsequential gene like the one determining eye colour.

The number of genes are irrelevant. What the hell kind of argument is that women are more like plants than men are because they have more genes?

Are women with Turner’s Syndrome less than other women because they have only one X chromosome? Are men with Klinefelter’s more than women because they have XXY karyotype? Or how about XXXY? They must be really bloody special; they must have the combined superpowers of a man and a woman, mustn’t they?

The reason the Y has so few genres is that it has evolved to deliver one specific gene that makes a world of difference. If it had a shit-load of other vital genes only one half of the population would inherit them. Thats why the genes that are exclusive to the Y chromosome, such as the SRY gene, are largely concerned with sexual dimorphism.

All men have an X chromosome. They have all the genes that women have, but they also have a Y chromosome that suppresses some of those genes and expresses other genes that women don’t have.

They come rushing in don't they? It's like a big sign saying "Don't go there".

I think the Smithsonian Institution in Washington is a pretty well-respected source. But let's all pretend it was just made up on Wordpress so we don't have to engage with any facts or discussion.

I think this is the topic women are really not allowed to talk about

The rest of the Y chromosome is a wasteland of meaningless repetition.

FWR derailers in a nutshell.