Y chromosome

[Watchfulwaiter]

To avoid current derail of thread about Dr Em

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

Look who’s talking.

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.

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.

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.

Always thank you for clarity. Science is so soothing.

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,

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."

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

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.’

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.

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.

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

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.

It is not being degraded. It is being streamlined

Not what I've read

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

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 ?

No but women might be having thought crimes by refusing to accept they are the inferior sex

In Cordelia Fine's Delusions of Gender she goes through , in meticulous detail, the experiments of male scientists who wished to prove beyond all doubt that men were the superior sex. It make for very interesting reading-- literally the lengths men have gone to over the centuries to convince themselves, and women, that they were superior. The experiments were all "bad science" of course, without proper controls and so on. They used similar experiments to "prove" black people were inferior

Knowledge about the degraded Y kind of knocks all those efforts on the head

And the trans idea that anyone can be a woman because women are incomplete humans, not really defineable in their own right--> such a reversal

No

Thank goodness for that.

If we're not even allowed thought crimes you can imagine how hard it is for women to organize protest riots for any cause. That's how tight the noose is

Sakura - I say this in the nicest possible way - WTAF are you on about?

Mary Daly was totally right, of course.

Women really aren't allowed to discuss this particular topic

You can always tell which topics are no go and it's always illuminating

When has discussion of the Y chromosome been off limits here? The biological basis of sex is central to the majority of threads.

That doesn't mean we have to ignore the actual science behind it all.