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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).

by 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?
  - roceasta 9y ago
    That's a pretty subtle case but I don't think it's relevant to the issue of human evolution for at least two reasons: (1) humans have universal intelligence which gives us the ability to adapt to any environment, (2) human evolution is now swamped by the evolution of memes, not genes. We now decide what to do (including whether to speciate or not) A more realistic analogy from the animal kingdom would be something like the case of farmed salmon which within a very few generations are less healthy than wild salmon. Also the famous 'mouse utopia' experiment. Both situations where the environment has been artificially manipulated by (human) ideas, just as our present environment is. Mutational loading is one explanation for the results. So have you considered the issue of mutational load: what's the greatest load we can sustain and what's its present level? Is it responsible, for example, for the declining birth rates in the West or is the explanation for that purely sociological? I would like to know the answers. However I presume that we'll start by using CRISPR or similar tech to eliminate known genetic diseases like Huntington's and Tay-Sachs. From that precedent should follow the identification and elimination of new and more silent genetic abnormalities. Which is reassuring.
    - evolve2017 9y ago
      I guess I would need to see an analysis of whether there's been any change in human allele frequencies. I suspect there hasn't. But to your example, one issue with the farmed fish is that they now constitute a closed gene pool - we can easily explain their decreased fitness with the likely rise of harmful alleles. With the explosion of population, I don't see much relationship between the salmon and humans.
      - roceasta 9y ago
        Thanks. I should read up a bit. Can you link to any decent info or discussion about allele frequencies?
        evolve2017 9y ago
        Incidentally, I'll be starting a PhD in a human genetics laboratory, but I don't have a lot of experience with this kind of literature. This seems like a reasonably accessible (college-biology level) discussion of what evolution would look like in the human gene pool: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933187/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933187/ ---- EDIT: I suspect you'll need a university library to access this, but Dr. Pardis Sabeti is well known in this area and also an amazing person - she played a big role in the molecular biology work that underlay the US response to the Ebola crisis. She wrote a review that explains the tools we currently have to ascertain human evolution: https://www.ncbi.nlm.nih.gov/pubmed/16778047 https://www.ncbi.nlm.nih.gov/pubmed/16778047
zanny 9y ago
Species also evolve in response to environmental stimuli. Nowadays anyone of any relatively normal genetic disposition can reproduce almost as much as they want. There is no selection bias in our children on a structural level - the beautiful smart people aren't having dramatically more babies. If anything, we are culturally selecting for poverty since the poorer you are the more children you have on average. Poverty itself is not a genetic trait, but the negative traits that can lead one into poverty are obviously going to be much more abundant.
- pbhjpbhj 9y ago
  The "negative" traits that lead to poverty in our Western Democracies might arguably include such things as empathy, charity, and a preference for cooperation instead of conflict. Selecting for people who "win" at Western capitalism seems likely to usher in a much worse distopia. I go for dumber people helping each other to live happy, fulfilled lives over intelligent super people destroying one another so they can control the most resources.
  - zanny 9y ago
    Absolutely true. I was concerned more with traits that can drive people from fiscal stability to poverty, like an addictive personality, how gullible they are, etc. The problem though is that happy dumb people will have an even harder time competing for scarce resources against genetically engineered unemphatic super geniuses than they do against the current crop of sociopaths that run the global economy.

by eggie 9y ago

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?
- roceasta 9y ago
  That's a pretty subtle case but I don't think it's relevant to the issue of human evolution for at least two reasons: (1) humans have universal intelligence which gives us the ability to adapt to any environment, (2) human evolution is now swamped by the evolution of memes, not genes. We now decide what to do (including whether to speciate or not) A more realistic analogy from the animal kingdom would be something like the case of farmed salmon which within a very few generations are less healthy than wild salmon. Also the famous 'mouse utopia' experiment. Both situations where the environment has been artificially manipulated by (human) ideas, just as our present environment is. Mutational loading is one explanation for the results. So have you considered the issue of mutational load: what's the greatest load we can sustain and what's its present level? Is it responsible, for example, for the declining birth rates in the West or is the explanation for that purely sociological? I would like to know the answers. However I presume that we'll start by using CRISPR or similar tech to eliminate known genetic diseases like Huntington's and Tay-Sachs. From that precedent should follow the identification and elimination of new and more silent genetic abnormalities. Which is reassuring.
  - evolve2017 9y ago
    I guess I would need to see an analysis of whether there's been any change in human allele frequencies. I suspect there hasn't. But to your example, one issue with the farmed fish is that they now constitute a closed gene pool - we can easily explain their decreased fitness with the likely rise of harmful alleles. With the explosion of population, I don't see much relationship between the salmon and humans.
    - roceasta 9y ago
      Thanks. I should read up a bit. Can you link to any decent info or discussion about allele frequencies?
      - evolve2017 9y ago
        Incidentally, I'll be starting a PhD in a human genetics laboratory, but I don't have a lot of experience with this kind of literature. This seems like a reasonably accessible (college-biology level) discussion of what evolution would look like in the human gene pool: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933187/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933187/ ---- EDIT: I suspect you'll need a university library to access this, but Dr. Pardis Sabeti is well known in this area and also an amazing person - she played a big role in the molecular biology work that underlay the US response to the Ebola crisis. She wrote a review that explains the tools we currently have to ascertain human evolution: https://www.ncbi.nlm.nih.gov/pubmed/16778047 https://www.ncbi.nlm.nih.gov/pubmed/16778047

zanny 9y ago

Species also evolve in response to environmental stimuli. Nowadays anyone of any relatively normal genetic disposition can reproduce almost as much as they want. There is no selection bias in our children on a structural level - the beautiful smart people aren't having dramatically more babies. If anything, we are culturally selecting for poverty since the poorer you are the more children you have on average. Poverty itself is not a genetic trait, but the negative traits that can lead one into poverty are obviously going to be much more abundant.

pbhjpbhj 9y ago
The "negative" traits that lead to poverty in our Western Democracies might arguably include such things as empathy, charity, and a preference for cooperation instead of conflict. Selecting for people who "win" at Western capitalism seems likely to usher in a much worse distopia. I go for dumber people helping each other to live happy, fulfilled lives over intelligent super people destroying one another so they can control the most resources.
- zanny 9y ago
  Absolutely true. I was concerned more with traits that can drive people from fiscal stability to poverty, like an addictive personality, how gullible they are, etc. The problem though is that happy dumb people will have an even harder time competing for scarce resources against genetically engineered unemphatic super geniuses than they do against the current crop of sociopaths that run the global economy.