I didn't hear of something like that, but think it's possible.

If you remember or find the info it would be interesting to know.

I actually had to look some infos up again and found another fun (?) fact.

In South America there are nine species of vole (genus Akodon) in which a quarter of female are XY, not XX. Their Y chromosome is complete with SRY, yet they still develop ovaries and produce viable eggs. That suggests they must have a entirely new master switch gene that can suppress SRY.

I don't know about that. I'm referring to J. M. Graves, a professor of evolutionary genetics. She looked at how the platypus Y was different to the human Y and calculated how much genetic material had been lost since our species diverged. That's how she got that time frame.

But she also told that some (male) scientists aren't fans of this and try to prove how stable the Y chromosome is.

SRY is like a conductor. It triggers the multiple genes to express testes or suppress ovaries. But those genes also trigger and suppress other genes. And while SRY is the trigger in some mammals, it's not necessary to kick start sex determination.

For example the platypus has five pairs of sex chromosomes. Females are XXXXXXXXXX and males are XXXXXYYYYY. Despite that many Y, on none of them SRY is found. One of those other interacting genes triggers sex determination. What's even more interesting those various involved genes can be found in similar combination throughout all vertebrae, but the trigger differs.

So while SRY is the trigger in some, it's not the only one.

Y chromosome in humans are getting shorter. It loses around 10 genes per million years. At this rate it will be gone in four and a half million years. Also sex-determination doesn't only involve the Y chromosome, but around 60 genes working in concert all over the genome.

You only want human facts? I've got some pretty interesting animal facts for the Y chromosome.

The question should be, what benefit does a determined sex have. Being a hermaphrodite doubles you're chances in a partner.

My guess is, the more complex the organism the harder a sex change is, so it's only beneficial in certain circumstances. Snails for example move very slowly and their senses aren't the best, so it's good if you can make children with every other individual of your species that you meet.

Sex change can often be found in fish, ocean is vast and it can be dangerous to venture out of your part of the reef, so it's great if one of your buddies can become a female when your original female dies. Or you're a male moray eel and never get to make little morays because your the runt of the reef, your genes would be lost, but at the end of your life you become a female and bam youre genes get to live on.

Then you have species with no need for sex, prospering with only female members.

Also male and female isn't answered with a simple XX or XY chromosome pair. There are species of frogs where in the north XX are female and XY are male, but in the south XX are male and XY are female and in the middle 50-50 chance. Sex isn't determined by only one chromosome. It's far more complicated and can differ between species.

Most of the time the answer to such more general questions is because it works and isn't a deadly disadvantage. To get a more specific answer you'll have to look at a more specific scenario (aka a specific species or environment).

You're more likely to catch another. You're immune system and overall body is stressed and needs time to recover. That's why it's important to rest and avoid strenuous activities like training. If you start to early to hard it can even lead to heart muscle inflammation.

You are more protected from the same strain of cold for some time.

Never heard a out that. Where did you get this from?

That's a interesting question and I think I will looks this up in more detail over the weekend, but for now I have this:

As far as I know this subject is still unclear. While autophagy would hinder cancer cells in early stages it also would help in later stages when the tumor gets bigger and the cells need more energy than can be provided (because blood vessels have to grow first). But that seems to differ from cancer type to cancer type, as far as I found (just a quick surface search for now).

There are some studies trying to find how to use autophagy to treat cancer.

Cancer cells don't die. Apoptosis doesn't work, so they divide more and more without old cells dying and making room for new ones.

But the new cells have to go somewhere. They are taking room while there is no room for them and may push against organs, blood vessels etc. They may do their original job like building hormones but also uncontrolled or even stop doing their job altogether. Some can infiltrate other tissue destroying it in the process.