5 ms·

The talk is of 'genetic enhancement' but the potential benefit seems more boring and necessary to me: removal of many new and as-yet-unidentified mutations. It

The talk is of 'genetic enhancement' but the potential benefit seems more boring and necessary to me: removal of many new and as-yet-unidentified mutations. It is thought that these have been accumulating generation by generation since about 1800 when child mortality started to fall.

evolve2017 9y ago
I would be very interested to read an academic paper that made this point. 200 years is a blink of an eye in almost any vertebrate's evolutionary time. Also, to support your claim, one would need evidence that the child mortality of the past reflected genetic unfitness (as opposed to poverty or the unavailability of antibiotics).
- sillysaurus3 9y ago
  200 years is a decent chunk of time from an evolutionary standpoint. We feel it's short because of how long our history has been. But within 200 years you can manufacture N new breeds of dogs, for example. We just underestimate how much change takes place in the world.
  - maxerickson 9y ago
    Dogs are fertile at 1 or 2 years of age. You can do an awful lot more in 100-150 generations than you can in 10-15 generations (probably more like 6-8. Checking my family tree, many of my great-great grandparents were born ~1850, so for me personally, 5 or 6 generations). In any case, we have to go back to the question that the GP asked, that dogs are malleable doesn't help us. Does reduced child mortality really cause more mutations to accumulate?
  - evolve2017 9y ago
    I think you're misunderstanding my point, but maybe I shouldn't have taken vertebrates as an example; we can of course imagine some island where massive selection pressures lead to speciation. I would be interested if you have such an example. However, dog breeds are not species and, given their non-random mating, don't really tell us much about whether 200 years is long in vertebrate evolutionary time. As far as humans go, I will grant that allele frequencies may have changed if you pick an isolated subpopulation of humans (say, everyone in Greenland) but even that seems extremely unlikely. As an aside, there are researchers who are using the caste system in India as a way to explore genetic architectures within a civilization. As these castes have existed for considerably longer than the period we're discussing, meaningful allele frequency changes may arise.
- roceasta 9y ago
  I'm not making a formal claim just sharing my thoughts. Though I do believe at least one evolutionary biologist has written about this: Hamilton W.D. (1999). The hospitals are coming. Narrow roads of gene land (Oxford University Press). Btw the phenomenon of 'mutational meltdown' is a closely related topic and may re-pay googling.
  - maxerickson 9y ago
    It seems to be a philosophical position more than anything: http://wasdarwinwrong.com/korthof97.htm http://wasdarwinwrong.com/korthof97.htm I would guess it is wrong; we are on a track where genetic manipulation to treat blatant defects will (relatively shortly) be cheaper than the traditional medical treatments.
    - nyolfen 9y ago
      this worry is not a fringe concern: https://www.edge.org/response-detail/26714 https://www.edge.org/response-detail/26714
      - maxerickson 9y ago
        Your link proposes that we will be able to manage mutations using genetic engineering. Parents could choose to have children created from their healthiest genes, rather than leaving children to be shotgunned with a random and increasing fraction of damaged genes. Genetic repair would replace the ancient cruelty of natural selection, which only fights entropy by tormenting organisms because of their genes. The concern espoused above is that we won't be able to fix the problem.
        visarga 9y ago
        > natural selection, which only fights entropy by tormenting organisms because of their genes Now that's a limited view of the process that created life. Natural evolution also pays back by upgrading the gene pool.
- telotortium 9y ago
  This isn't an academic paper but at least one academic, John Tooby, has gone on the record as strongly believing that mutations are accumulating in the human population due precisely to this: https://www.edge.org/response-detail/26714 https://www.edge.org/response-detail/26714.
eggie 9y ago
Why would you throw away the biodiversity of our species? You're forgetting about the huge bulk of mutations that have been tested (and were embryonic lethal). Our rapidly growing species has only accumulated mutations that don't cause us to die, and that's an immensely valuable resource to have. The evolution rate of a species is proportional to its genetic diversity.
- roceasta 9y ago
  >Our rapidly growing species has only accumulated mutations that don't cause us to die Hygiene, nutrition and medicine (all good things!) also cause us to remain alive where previously natural selection would not have favoured those bearing too great a mutational load. I doubt that existing mutations have been fully 'tested'. We know that the majority of mutations are harmful and that the brain is far from fully-developed prior to birth, for instance. Being complex there are many genes which control its development and it seems plausible that the result could be sub-optimal without obvious signs of disease or disability. Other things being equal, we could be slower, less resilient, less fertile, etc, than our 18th century forebears.
  - evolve2017 9y ago
    I don't think you can remove a discussion about changes in allele frequencies from environments. Thus, making 'other things being equal' is not a reasonable premise from which to discuss evolution. I do see the argument you are espousing but I would only suggest that you consider the broader context of what happens when new species arise. I suspect you care more about the elimination of alleles (which is surprisingly hard to do), but this is a good example for why I disagree: One possibility for speciation is the creation of a new niche (lets say a new type of tree grows on an island, its seeds having been carried there by an unusual current). Here, organisms might have increased reproductive opportunities over their neighbors by exploiting this new tree. In time, one could imagine organisms that live in the new tree, like microbes, could acquire enough new features to constitute a new species. Consider the case where organisms from the original population become unable to grow on the new tree. If the new species is also unable to grow in the original environment, how can we say either is more or less resilient?

evolve2017 9y ago

I would be very interested to read an academic paper that made this point. 200 years is a blink of an eye in almost any vertebrate's evolutionary time. Also, to support your claim, one would need evidence that the child mortality of the past reflected genetic unfitness (as opposed to poverty or the unavailability of antibiotics).

sillysaurus3 9y ago
200 years is a decent chunk of time from an evolutionary standpoint. We feel it's short because of how long our history has been. But within 200 years you can manufacture N new breeds of dogs, for example. We just underestimate how much change takes place in the world.
- maxerickson 9y ago
  Dogs are fertile at 1 or 2 years of age. You can do an awful lot more in 100-150 generations than you can in 10-15 generations (probably more like 6-8. Checking my family tree, many of my great-great grandparents were born ~1850, so for me personally, 5 or 6 generations). In any case, we have to go back to the question that the GP asked, that dogs are malleable doesn't help us. Does reduced child mortality really cause more mutations to accumulate?
- evolve2017 9y ago
  I think you're misunderstanding my point, but maybe I shouldn't have taken vertebrates as an example; we can of course imagine some island where massive selection pressures lead to speciation. I would be interested if you have such an example. However, dog breeds are not species and, given their non-random mating, don't really tell us much about whether 200 years is long in vertebrate evolutionary time. As far as humans go, I will grant that allele frequencies may have changed if you pick an isolated subpopulation of humans (say, everyone in Greenland) but even that seems extremely unlikely. As an aside, there are researchers who are using the caste system in India as a way to explore genetic architectures within a civilization. As these castes have existed for considerably longer than the period we're discussing, meaningful allele frequency changes may arise.
roceasta 9y ago
I'm not making a formal claim just sharing my thoughts. Though I do believe at least one evolutionary biologist has written about this: Hamilton W.D. (1999). The hospitals are coming. Narrow roads of gene land (Oxford University Press). Btw the phenomenon of 'mutational meltdown' is a closely related topic and may re-pay googling.
- maxerickson 9y ago
  It seems to be a philosophical position more than anything: http://wasdarwinwrong.com/korthof97.htm http://wasdarwinwrong.com/korthof97.htm I would guess it is wrong; we are on a track where genetic manipulation to treat blatant defects will (relatively shortly) be cheaper than the traditional medical treatments.
  - nyolfen 9y ago
    this worry is not a fringe concern: https://www.edge.org/response-detail/26714 https://www.edge.org/response-detail/26714
    - maxerickson 9y ago
      Your link proposes that we will be able to manage mutations using genetic engineering. Parents could choose to have children created from their healthiest genes, rather than leaving children to be shotgunned with a random and increasing fraction of damaged genes. Genetic repair would replace the ancient cruelty of natural selection, which only fights entropy by tormenting organisms because of their genes. The concern espoused above is that we won't be able to fix the problem.
      - visarga 9y ago
        > natural selection, which only fights entropy by tormenting organisms because of their genes Now that's a limited view of the process that created life. Natural evolution also pays back by upgrading the gene pool.
telotortium 9y ago
This isn't an academic paper but at least one academic, John Tooby, has gone on the record as strongly believing that mutations are accumulating in the human population due precisely to this: https://www.edge.org/response-detail/26714 https://www.edge.org/response-detail/26714.

eggie 9y ago

Why would you throw away the biodiversity of our species? You're forgetting about the huge bulk of mutations that have been tested (and were embryonic lethal). Our rapidly growing species has only accumulated mutations that don't cause us to die, and that's an immensely valuable resource to have. The evolution rate of a species is proportional to its genetic diversity.

roceasta 9y ago
>Our rapidly growing species has only accumulated mutations that don't cause us to die Hygiene, nutrition and medicine (all good things!) also cause us to remain alive where previously natural selection would not have favoured those bearing too great a mutational load. I doubt that existing mutations have been fully 'tested'. We know that the majority of mutations are harmful and that the brain is far from fully-developed prior to birth, for instance. Being complex there are many genes which control its development and it seems plausible that the result could be sub-optimal without obvious signs of disease or disability. Other things being equal, we could be slower, less resilient, less fertile, etc, than our 18th century forebears.
- evolve2017 9y ago
  I don't think you can remove a discussion about changes in allele frequencies from environments. Thus, making 'other things being equal' is not a reasonable premise from which to discuss evolution. I do see the argument you are espousing but I would only suggest that you consider the broader context of what happens when new species arise. I suspect you care more about the elimination of alleles (which is surprisingly hard to do), but this is a good example for why I disagree: One possibility for speciation is the creation of a new niche (lets say a new type of tree grows on an island, its seeds having been carried there by an unusual current). Here, organisms might have increased reproductive opportunities over their neighbors by exploiting this new tree. In time, one could imagine organisms that live in the new tree, like microbes, could acquire enough new features to constitute a new species. Consider the case where organisms from the original population become unable to grow on the new tree. If the new species is also unable to grow in the original environment, how can we say either is more or less resilient?