Would this be possible? Sex ratio

[Chaotic Neutral]

I was thinking about ways to reduce the world population without killing anybody, and I had an interesting thought:

Would be possible to change the X gene or introduce a disease in humans that would either kill all Y-chromosome fetuses, or make the X gene dominant to the Y and cause XY females?

If this is possible, it would only need to be done a few times to have a massive effect on the world's population.

The first child has 2 female children, the second generation have 4 female children, 8, 16 ,32, 64, 128 ect...

I probably got something wrong though, so feel free to call me an idiot.

[Chaotic Neutral]

Thinking about it more, rendering the Y children impotent would also work, but the trait would multiply much more slowly, making it much less useful.

[Lusankya]

You are aware that population growth rate is limited more by the number of females than the number of males, right?

All that would happen is that the males who were more resistant to the disease would get multiple women, and everything would be back to normal in a short period of time.

[Chaotic Neutral]

Do men generally get as many women as there are available now? I don't see why it wouldn't just result in lots of women not having kids.

[Lusankya]

That's not the way it worked in the past. I don't see why you think that it would be any different now that we're more "enlightened" or whatever.

[Chaotic Neutral]

My question isn't whether it would wear off over time, it's whether or not it is possible for it to be done on purpose, and whether or not it would be effective.

By the time polygamy becomes universally accepted, it would have already done it's job.

[Lusankya]

I think that polygamy would become universally accepted at about the same time that these kids who grew up with a skewed gender ratio grew up.

And really, it's not going to work. If it takes effect at all, it will take effect one generation from the time the disease gets out to the time it would have any effect on foetuses. This means that it wouldn't actually have any effect on population growth until about 2050 (assuming it got out today). That's also assuming that the lack of male babies doesn't cause a massive spike in the birthrate as people suddenly start to really, really try for a boy.

[Chaotic Neutral]

What about a modifying the X chromosome to do something that kill males fetuses? Impossible?

[The Duchess of Zeon]

Uhm, there's been studies done suggesting that the sex ratio can be as high as 40 fertile women for every fertile male with no consequence for population health or stability.

[Chaotic Neutral]

Uhm, there's been studies done suggesting that the sex ratio can be as high as 40 fertile women for every fertile male with no consequence for population health or stability.

So, it would at least ensure a bright future for men, and women would be free of discrimination?

[Sarevok]

The OP is the dumbest possible attempt to cover an excuse to have a personal harem for the average joe.

Uhm, there's been studies done suggesting that the sex ratio can be as high as 40 fertile women for every fertile male with no consequence for population health or stability.

One only needs to look at how many kids Saudi royals father to see this in practice...

[Lusankya]

What about a modifying the X chromosome to do something that kill males fetuses? Impossible?

Eh. You could probably make something like that. Nature does have things like haemophilia which, while not killing of male foetuses, do pretty much guarantee that any male with the gene isn't likely to enter the breeding population.

I'm just not sure:

a) why you'd do it, since it's been pointed out that the idea's not going to work anyway.

or

b) how you expect this kind of modified X chromosome to spread through the population. Once people know what's going on, they'll deliberately select for it to not get passed onto future generations - much like we do with genetic defects today. And it's going to get noticed and dealt with long before it has any impact on population growth.

[Stark]

I guess this is from the idiot school of 'crippling people forever is better than abortion and birth control'.

[Chaotic Neutral]

I guess this is from the idiot school of 'crippling people forever is better than abortion and birth control'.

How is only being able to have female children "crippling".

Once people know what's going on, they'll deliberately select for it to not get passed onto future generations - much like we do with genetic defects today. And it's going to get noticed and dealt with long before it has any impact on population growth.

So it could only work in developing countries that can't afford to fix it?

[Simon_Jester]

Basically:

1) No it won't work, because as others have pointed out, skewing the male-female ratio in favor of many females per male has pretty much zero effect on population growth.

2) The timing is totally fucked up, suggesting a lack of analysis of the problem. You're proposing to solve an overpopulation problem that's going to really bite down on us in the next hundred years... with a vaporware genetic technique that's not going to have any noticeable demographic effect for several hundred years because of doubling time. At least, assuming you need volunteers; see (3).

3) The bioethics problem is staggering: this idea is not only deeply flawed, it's deeply wrong if you're trying to modify people without their consent. As for modifying them with their consent, you're never going to find enough volunteers.

4) There's a fine line between "this plan can conceivably work" and "this plan brings about the extinction of the human race as the breeding population collapses."

[Lusankya]

Once people know what's going on, they'll deliberately select for it to not get passed onto future generations - much like we do with genetic defects today. And it's going to get noticed and dealt with long before it has any impact on population growth.

So it could only work in developing countries that can't afford to fix it?

It won't even work there, because they'd just have 50% more kids to make up for the lack of sons.

[Freefall]

Just think about a hypothetical situation like this: you've got a lush, deserted tropical island with 50 shipwrecked people, all young adults, all reasonably attractive and healthy. The island has enough food to take care of all their nutritional needs easily.

Now, say the composition is 49 women and 1 man. At the end of a year, you could have between 0 and 49 babies (ignoring twins & such)

Now switch it; 49 men and 1 woman. At the end of the year, you could have between 0 and 1 baby (ignoring twins & such), and possibly a bunch of dead men.

In that regard, sure, decreasing the relative number of women will slow population growth, but it could be a pretty ugly way to go about it.

If you really have to do something like this (which, well, you don't, at all, and thankfully can't), mass sterilization is going to be a lot easier than fucking with people's genes to throw off the sex ratio of the entire planet. That way at least everyone can still enjoy sex and a relationship (or rather, their odds won't be any worse than they would be anyway). Yes, having kids is a really big deal to a lot of people, but at least you're not asking them to be alone their whole lives in addition to that.

I'll also point out that it is fairly common for men in America to have multiple children with multiple women. Usually it's not at the same time, but that happens too. There's a reason the term "baby's mama" exists, and it isn't just for laughs. And America is pretty conservative with the whole monogamy thing, as far as I'm aware. I really don't see why it would take very long for open polygamy to become more normal.

And isn't it mainly the 3rd world that is the problem with overpopulating anyway (although the 1st world is the problem with resource consumption, which is the other issue with "overpopulation"; there's lots of food, just not enough people are getting it).

Damn, how were that many posts made since I started typing. Looks like there's a general consensus of "terrible idea."

[Stark]

It won't even work there, because they'd just have 50% more kids to make up for the lack of sons.

Frankly the violence that is likely to ensure from misunderstandings of how the trait is passed or communicated would reduce the population more than this stupid idea.

[Lord of the Abyss]

What about a modifying the X chromosome to do something that kill males fetuses? Impossible?

Eh. You could probably make something like that. Nature does have things like haemophilia which, while not killing of male foetuses, do pretty much guarantee that any male with the gene isn't likely to enter the breeding population.

It's my understanding that natural versions of such X chromosomes are believed to occur on a fairly regular basis, on an evolutionary timescale. The X and Y are in competition, with the X having the advantage because it's present in both genders. And an X that prevents the conception of male children has a short term advantage* because it will spread itself faster, since an XX female will carry two X copies while an XY male carries only one and so might not inherit the mutant X. So there appears to be a long term cycle; a mutant x appears that prevents males from being born and spreads; eventually a variant of the Y shows up that can overcome the "killer X" and spreads rapidly until it replaces the old "Y". Then the status quo stabilizes until the next mutant X comes along.


* interestingly I've read that the opposite is a fairly common mutation among insects. There's a single male gene mutation that causes male eggs with the mutation to poison any eggs lacking the mutant gene; naturally that includes all female eggs, which is a very effective short term method for the mutant gene to ensure it spreads. Until of course the insect population starts running low on females. Since it takes only a single mutation it can easily pop up spontaneously despite being such a long term disaster.

[someone_else]

It's far more effective (and ludicrously more profitable, more than paying for itself) to set up a pointless war and send loads of poor (i mean economically) people to charge machinegun nests with their bare chest, just like WWI. It is also trivial to do in comparison to the level of genetic engineering required for your proposal.

That said, I'd like to add that diseases can be engineered, but the rather fast reproduction rates of the virus/bacteria (faster are the virus) will mean they will get totally out of control (mutations and exchange of genetic material with other pathogens) and rape your virgin ass in less than a decade.

Since you need to keep those pathogens always active to have the desidered effect, it's bound to fuck up horribly.


Then you talked of fucking up X gene somewhay.

Be aware that by current technology it's impossible to change the genome of an adult being.
They tried with retroviruses but it usually gives more pains than it is worth (mostly because the virus cannot place the new genes in the correct spot, and mutiple such viruses keep re-infecting the same cells fucking everything up even further).

So, any and all genetic modification has to be done on zygotes. And it will be fun as hell since there are no ways to ensure perfect survival nor perfect genes placement in the zygotes.
So you are going to lose loads of zygotes due to either lethality of gene insertion.
You still have a bucket of zygotes that didn't give a fuck and trashed the new genes you inserted in them, and of the very tiny percentage of zygotes that have integrated the new genes in their genome, a fucking load will have the gene integrated in the wrong place.

Then there is the fun of implantation, which means you lose again around 2/3 of the zygotes you are trying to implant.

Now, assuming pro-life movements and other morons of similar beliefs didn't burn you and your labs for "zygote mass destruction", let me ask a question:

You think that we have enough labs to do this to have anywhere around a few hundred millions GM humans per year (a grossly eyeballed amount of First World total birth rate)? I think not. Also the machinery (and people working at it) isn't cheap.

3) The bioethics problem is staggering: this idea is not only deeply flawed, it's deeply wrong if you're trying to modify people without their consent. As for modifying them with their consent, you're never going to find enough volunteers.

Uhm, never thought about this. If I modify a zygote, do I need consent of anyone? I think you shouldn't, after the sperm and egg donors gave you the starting material to work with, you can do whatever you want with them.

[Broomstick]

I was thinking about ways to reduce the world population without killing anybody, and I had an interesting thought:

Would be possible to change the X gene or introduce a disease in humans that would either kill all Y-chromosome fetuses, or make the X gene dominant to the Y and cause XY females?

If this is possible, it would only need to be done a few times to have a massive effect on the world's population.

The first child has 2 female children, the second generation have 4 female children, 8, 16 ,32, 64, 128 ect...

I probably got something wrong though, so feel free to call me an idiot.

Well, sure, it's possible to have XY females, they crop up in the human population naturally all the time. The trait actually runs in some families - passed through the XX females. However, one flaw in your thinking (which may be based on a lack of knowledge) is that XY females are always sterile - they don't have ovaries, and their testicular tissue never properly develops. They just don't produce gametes, and have no means of doing so.

So, these types of folks already exist and they haven't taken over the world or made any sort of dent in population growth. No, it wouldn't work, as demonstrated by reality.

Unless you really killed every fetus with a Y, in which case the human race goes extinct because there are no males left for breeding stock. Which does end the population overgrowth problem but not in a way I think people would like to see it happen.

3) The bioethics problem is staggering: this idea is not only deeply flawed, it's deeply wrong if you're trying to modify people without their consent. As for modifying them with their consent, you're never going to find enough volunteers.

Uhm, never thought about this. If I modify a zygote, do I need consent of anyone? I think you shouldn't, after the sperm and egg donors gave you the starting material to work with, you can do whatever you want with them.

The problem is when the zygote is gestated then grows up into a human being who might or might not be pissed off that whatever fucked up problem they have is due to a human who might be held liable in a court of law as opposed to random chance. This is why diddling with the DNA of animals is usually considered OK while fucking up human genomes is usually forbidden territory.

[LionElJonson]

Actually, I'll point out that there's a parasite that spreads among insects that turns the males into females, and causes females to give birth parthenogenetically, so something like this is vaguely possible.

It wouldn't stop population growth, though, just decrease genetic diversity.

[Alyrium Denryle]

I was thinking about ways to reduce the world population without killing anybody, and I had an interesting thought:

Would be possible to change the X gene or introduce a disease in humans that would either kill all Y-chromosome fetuses, or make the X gene dominant to the Y and cause XY females?

If this is possible, it would only need to be done a few times to have a massive effect on the world's population.

The first child has 2 female children, the second generation have 4 female children, 8, 16 ,32, 64, 128 ect...

I probably got something wrong though, so feel free to call me an idiot.

Have you considered having yourself sterilized to avoid inflicting your offspring on the rest of the world?

Fucking with the sex ratio is bad. It will end up killing people, lots of people. Regardless of how you do it (say, creating lots of sterile women), you will not get a nice slow and steady population drop. The age structure will invert, causing massive economic problems as the work force ages, and then collapses.

If you are going to do anything, getting birth rates just under 2 offspring per female is how to do it, because it it will result in a stabilization of the population and a gradual drop.

[Coyote]

Uhm, there's been studies done suggesting that the sex ratio can be as high as 40 fertile women for every fertile male with no consequence for population health or stability.

Sign me up! --err-- I mean, that would be horrible.




Heeheehee.




Was there ever a way to figure out what would be the least amount of people (and what their sex ratios would have to be) would be needed to drop off on a planet and leave as a viable colony with enough genetic diversity to keep inbreeding from being a problem? The inbreeding would be a genetic factor to figure in sex ratios; the social factors would be something different and not necessarily related.

[Alyrium Denryle]

Uhm, there's been studies done suggesting that the sex ratio can be as high as 40 fertile women for every fertile male with no consequence for population health or stability.

Sign me up! --err-- I mean, that would be horrible.




Heeheehee.




Was there ever a way to figure out what would be the least amount of people (and what their sex ratios would have to be) would be needed to drop off on a planet and leave as a viable colony with enough genetic diversity to keep inbreeding from being a problem? The inbreeding would be a genetic factor to figure in sex ratios; the social factors would be something different and not necessarily related.

Well, it HAS gotten to 5000ish in the past, and we are not all Quasimodo