I tried looking into this in much more depth and doing some calculations a few months ago, but I found it frustrating to get exact numbers and the range ended up being too large. So, I am going to comment without using exact numbers, but give the overall point.
Basically, men's sperm has an extremely small number of mutations each year (1 or 2). Bronski is concerned about a major impact from the accumulated mutations due to father's age. He thinks this is a big deal. I haven't looked into the question very much, but we can imagine it isn't.
The issue with IVG is that we are taking somatic cells and converting them to iPSCs and then to oocytes. Oocytes aren't continually reproduced like sperm are, so they don't keep getting more mutations as a woman gets older. However, a woman's somatic cells (like blood cells) keep being produced and there are accumulating mutations that are even larger than the mutation rate in sperm--perhaps much larger. Over her lifetime, the accumulated mutations could be way larger. It might be so large that we should be concerned, even if we don't think it's much of an issue with paternal age.
An incredible number of people are never born all the time, like literally every month for every woman. If that's a tragedy we ought to be forcing people to get pregnant and bring to term. Whatever trouble it causes, it creates a life!
Feels pretty repugnant conclusion to me. Ending in "give baby to two sex weirdoes who will probably molest it and deny it a mother because hey better then not existing" has that absurdistan feel to it.
In reality I think it's pretty easy to make the case that IVF passes the cost benefit test. I'm a bit skeptical of surrogacy for non-infertility reasons, though artificial wombs will probably solve that soon.
IVG will happen but I'm not in line to the be the first person to do it. Feels way more sci-fi then "pick the best of normal embryos".
"Whatever negative aspects you believe there are to never meeting one’s biological mother, it is quite difficult to imagine that never having been born is better."
For me, the argument is not never meeting one's biological mother but never knowing who she is.
"An extreme adherent to this view might see no need to save the life of a child whose mother has died during labor."
One situation is purposeful, and the other is accidental.
"If surrogacy for gay couples were made illegal, the counterfactual is not that the surrogate mother keeps the baby. The correct counterfactual is that the child would have never been created in the first place."
You appear to be showing concern for all the potential children who were never conceived.
With this attitude in mind, how can you defend embryo selection, which destroys potential children who will never be born?
"Surely, a potentially less than perfectly healthy child is better than no child at all."
For who, the parents or the child?
Let it be known that I am a strong supporter of IVF, embryo selection, and genetic enhancement. I am pointing out possible lapses in continuity of reasoning.
"For me, the argument is not never meeting one's biological mother but never knowing who she is."
Fair enough, but surely this is not a fate worse than not existing?
"You appear to be showing concern for all the potential children who were never conceived. With this attitude in mind, how can you defend embryo selection, which destroys potential children who will never be born?"
The correct comparison for polygenic embryo selection is transferring (a) an embryo with known low PRS with (b) an embryo with a high visually assigned embryo grade. I prefer (a) to (b). Both choices result in excess embryos not becoming people.
"Surely, a potentially less than perfectly healthy child is better than no child at all."
For both.
"Let it be known that I am a strong supporter of IVF, embryo selection, and genetic enhancement. I am pointing out possible lapses in continuity of reasoning."
I don't see the lapses. It seems coherent and consist to me.
"Fair enough, but surely this is not a fate worse than not existing?"
Agreed.
"I don't see the lapses. It seems coherent and consist to me."
Well, this statement: 'The correct counterfactual is that the child would have never been created in the first place.' leads me to wonder why you only have a concern about an uncreated child in this particular case and not the millions and millions that have not been created.
"I am concerned about the millions and millions of people who could exist but are never created."
I understand your position. There is only one situation where quantity is better than quality, and that is when the quantity refers to quality. In other words, quality is better than quantity.
Thank you for the link. I agree there is a lower level of population that should not be breached. However, the level of a sustainable population can be lower in a higher-quality population.
> Even with a reduced baseline due to higher mutational load, expected returns would likely make this an attractive proposition.
Furthermore, mutational load is probably a nothingburger: https://www.sebjenseb.net/p/taking-mutational-load-seriously
I tried looking into this in much more depth and doing some calculations a few months ago, but I found it frustrating to get exact numbers and the range ended up being too large. So, I am going to comment without using exact numbers, but give the overall point.
Basically, men's sperm has an extremely small number of mutations each year (1 or 2). Bronski is concerned about a major impact from the accumulated mutations due to father's age. He thinks this is a big deal. I haven't looked into the question very much, but we can imagine it isn't.
The issue with IVG is that we are taking somatic cells and converting them to iPSCs and then to oocytes. Oocytes aren't continually reproduced like sperm are, so they don't keep getting more mutations as a woman gets older. However, a woman's somatic cells (like blood cells) keep being produced and there are accumulating mutations that are even larger than the mutation rate in sperm--perhaps much larger. Over her lifetime, the accumulated mutations could be way larger. It might be so large that we should be concerned, even if we don't think it's much of an issue with paternal age.
I think we could use other cells that don’t have the mutation problem. But the epigenetics will be an issue potentially
Well said.
"Never being born."
An incredible number of people are never born all the time, like literally every month for every woman. If that's a tragedy we ought to be forcing people to get pregnant and bring to term. Whatever trouble it causes, it creates a life!
Feels pretty repugnant conclusion to me. Ending in "give baby to two sex weirdoes who will probably molest it and deny it a mother because hey better then not existing" has that absurdistan feel to it.
In reality I think it's pretty easy to make the case that IVF passes the cost benefit test. I'm a bit skeptical of surrogacy for non-infertility reasons, though artificial wombs will probably solve that soon.
IVG will happen but I'm not in line to the be the first person to do it. Feels way more sci-fi then "pick the best of normal embryos".
"Whatever negative aspects you believe there are to never meeting one’s biological mother, it is quite difficult to imagine that never having been born is better."
For me, the argument is not never meeting one's biological mother but never knowing who she is.
"An extreme adherent to this view might see no need to save the life of a child whose mother has died during labor."
One situation is purposeful, and the other is accidental.
"If surrogacy for gay couples were made illegal, the counterfactual is not that the surrogate mother keeps the baby. The correct counterfactual is that the child would have never been created in the first place."
You appear to be showing concern for all the potential children who were never conceived.
With this attitude in mind, how can you defend embryo selection, which destroys potential children who will never be born?
"Surely, a potentially less than perfectly healthy child is better than no child at all."
For who, the parents or the child?
Let it be known that I am a strong supporter of IVF, embryo selection, and genetic enhancement. I am pointing out possible lapses in continuity of reasoning.
"For me, the argument is not never meeting one's biological mother but never knowing who she is."
Fair enough, but surely this is not a fate worse than not existing?
"You appear to be showing concern for all the potential children who were never conceived. With this attitude in mind, how can you defend embryo selection, which destroys potential children who will never be born?"
The correct comparison for polygenic embryo selection is transferring (a) an embryo with known low PRS with (b) an embryo with a high visually assigned embryo grade. I prefer (a) to (b). Both choices result in excess embryos not becoming people.
"Surely, a potentially less than perfectly healthy child is better than no child at all."
For both.
"Let it be known that I am a strong supporter of IVF, embryo selection, and genetic enhancement. I am pointing out possible lapses in continuity of reasoning."
I don't see the lapses. It seems coherent and consist to me.
"Fair enough, but surely this is not a fate worse than not existing?"
Agreed.
"I don't see the lapses. It seems coherent and consist to me."
Well, this statement: 'The correct counterfactual is that the child would have never been created in the first place.' leads me to wonder why you only have a concern about an uncreated child in this particular case and not the millions and millions that have not been created.
I guess we disagree here.
I am concerned about the millions and millions of people who could exist but are never created (https://www.parrhesia.co/p/in-favor-of-underpopulation-worries).
"I am concerned about the millions and millions of people who could exist but are never created."
I understand your position. There is only one situation where quantity is better than quality, and that is when the quantity refers to quality. In other words, quality is better than quantity.
Thank you for the link. I agree there is a lower level of population that should not be breached. However, the level of a sustainable population can be lower in a higher-quality population.