2. Increasing healthy lifespan will probably lead to smarter average citizens even if there’s no direct effect on IQ. This is simply because a lower percentage of citizens will be in the development phase.
3. There’s a paper I read a few weeks ago suggesting that there’s far less pleiotropy (genes that have two distinct effects) than we previously thought. If this is the case, we would expect many genes to affect mostly longevity rather than nearly all affecting both longevity and intelligence.
As far as the “this generation vs next-generation” question, I think that there ARE probably some changes you could make to the current generation, particularly by modifying stem cell populations. But there are always going to be some changes that can only be feasibly made in embryos (particularly those that affect developmental growth). Until we get extremely advanced nanotech, those types of changes are only going to have an effect if made in embryos or young children. And if your nanotech is that advanced this all may be a moot question because you might just synthesize entirely new designs for bodies and brains that aren’t even possible by simply modifying genes.
There’s also a knowledge constraint on our ability to modify the genes of adult humans. For highly polygenic traits in particular, we know the rough regions that correlate to the expression of the trait, but in most cases, we don’t know the precise gene in that region that is responsible for the observed variance. We’ll have narrowed it down to 10 or 11 candidate genes, but we don’t know the single gene responsible.
This makes genetic engineering of such traits highly impractical with tools like CRISPR because we’d have to cut and replace ten times the number of genes that we actually want to replace. And given CRISPRs continued issues with off-target edits, this is likely impossible with current technology.
It’s much easier to modify such polygenic traits with embryo selection methods, which as the name suggests, can only be performed by selecting one embryo out of a large batch.
I am quite optimistic about our ability to increase both intelligence and longevity for a few reasons:
1. Intelligence correlates quite strongly with longevity. It therefore seems likely unlikely that optimizing for increased intelligence will have a negative effect on lifespan in the short term.
2. Increasing healthy lifespan will probably lead to smarter average citizens even if there’s no direct effect on IQ. This is simply because a lower percentage of citizens will be in the development phase.
3. There’s a paper I read a few weeks ago suggesting that there’s far less pleiotropy (genes that have two distinct effects) than we previously thought. If this is the case, we would expect many genes to affect mostly longevity rather than nearly all affecting both longevity and intelligence.
As far as the “this generation vs next-generation” question, I think that there ARE probably some changes you could make to the current generation, particularly by modifying stem cell populations. But there are always going to be some changes that can only be feasibly made in embryos (particularly those that affect developmental growth). Until we get extremely advanced nanotech, those types of changes are only going to have an effect if made in embryos or young children. And if your nanotech is that advanced this all may be a moot question because you might just synthesize entirely new designs for bodies and brains that aren’t even possible by simply modifying genes.
There’s also a knowledge constraint on our ability to modify the genes of adult humans. For highly polygenic traits in particular, we know the rough regions that correlate to the expression of the trait, but in most cases, we don’t know the precise gene in that region that is responsible for the observed variance. We’ll have narrowed it down to 10 or 11 candidate genes, but we don’t know the single gene responsible.
This makes genetic engineering of such traits highly impractical with tools like CRISPR because we’d have to cut and replace ten times the number of genes that we actually want to replace. And given CRISPRs continued issues with off-target edits, this is likely impossible with current technology.
It’s much easier to modify such polygenic traits with embryo selection methods, which as the name suggests, can only be performed by selecting one embryo out of a large batch.