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> Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use. This is actually one of th

> Time is a really good curator - if something survives a really long time (thousand of years scale) it is very likely to be of use. This is actually one of the fallacies related to evolution. Selection only happens against negative pressure, not for positive pressure. In other words, adaptation generally only happens for things which harm survival. Things which are neutral or even benefit survival are not selected for. Therefore, the proper statement to make would be more along the lines of, "Well, it can't hurt too much."

cma 11y ago
Sexual selection can be much more powerful than ordinary survival selection (see: peacock tails).
- jdmichal 11y ago
  True. Instances of "survival" in my original statement should probably be read as "reproduction". There are, of course, more selection criteria available than just "survival to reproduction age". And selections can work opposing each other. But, in all, the original statement still stands: Selections only work negatively. That is, a peacock with better plumage might get more chances of reproducing due to sexual selection, but as long as he gets at least one chance of reproduction, he has not been selected against.
  - cma 11y ago
    Reproduction causes a loss of half of the chromosomes. If he only has one offspring (unless it is a lot more sexually successful than him), his line dies out. Different organisms have evolved different reproduction strategies through selection: https://en.m.wikipedia.org/wiki/R/K_selection_theory https://en.m.wikipedia.org/wiki/R/K_selection_theory
    - jdmichal 11y ago
      You're being pretty pedantic at this point. If an individual reproduces, then none of that individual's traits were sufficiently selected against. That's also not a guarantee that all their traits will carry on in new lines. There's also no guarantee that their children will be fit, due to differing traits or changing environment.
knodi123 11y ago
> Things which [...] benefit survival are not selected for Things which impact reproduction will be selected for. Things which kill you before you can finish raising a child will be most strongly selected against. Things that allow you to keep reproducing longer will be less strongly selected for. I guarantee that if there were a gene that let men and woman keep popping out babies for a century, it would be very likely to be preserved.
- jdmichal 11y ago
  > Things that allow you to keep reproducing longer will be less strongly selected for. No. This is the fallacy. > I guarantee that if there were a gene that let men and woman keep popping out babies for a century, it would be very likely to be preserved. It would be preserved, yes. The fallacy is that it will not be perserved in preference of lack of the gene, because there is nothing selecting against not having that gene. In other words, both lines will continue to live on, because there is nothing selecting against either of them. As long as individuals can reproduce, then their traits are not being selected against. If there are multiple variations of the traits, those will become part of the population's natural variation. Which is a good thing to have in terms of the population, because natural variation helps prevent genetic bottlenecks.
  - knodi123 11y ago
    > No. This is the fallacy. I simply don't believe you. As the one making the preposterously counterintuitive claim, it's up to you to support this with facts, beyond just saying "nope, you're wrong, it's a fallacy."
    - knodi123 11y ago
      To elaborate, if Sensible Sally's female descendants all produce one child, and Fertile Myrtle's descendants all produce 10 children each, then Myrtle's genes will multiply faster, and be less vulnerable to being wiped out by the odd plague or war.
      - 11y ago
Noosterdam 11y ago
Nothing is neutral. Every activity one undertakes is at the cost of doing something else, hence "neutral" is actually negative - and would get selected against, ex hypothesi. Even things that benefit survival but don't do it strongly enough would be functionally negative, and therefore selected against. Finally, take activities that are strongly beneficial. Not doing these things will put one at a selective disadvantage against one's rivals. If you agree with the above, there is no validity at all left in your original claim: >Things which are neutral or even benefit survival are not selected for.
- jdmichal 11y ago
  If I understand correctly, your basic argument is something along the lines of, "Eating is obviously extremely beneficial. Therefore eating must be selected for. Therefore your statement is false." My rebuttal would be that you are looking at the wrong side of the equation. Eating is not selected for; not eating is selected against. So no, your argument does not counter my original claim. Such reworkings of the argument may seem petty, but they are centered around a deeper understanding of what exactly selection is and how it works.

cma 11y ago

Sexual selection can be much more powerful than ordinary survival selection (see: peacock tails).

jdmichal 11y ago
True. Instances of "survival" in my original statement should probably be read as "reproduction". There are, of course, more selection criteria available than just "survival to reproduction age". And selections can work opposing each other. But, in all, the original statement still stands: Selections only work negatively. That is, a peacock with better plumage might get more chances of reproducing due to sexual selection, but as long as he gets at least one chance of reproduction, he has not been selected against.
- cma 11y ago
  Reproduction causes a loss of half of the chromosomes. If he only has one offspring (unless it is a lot more sexually successful than him), his line dies out. Different organisms have evolved different reproduction strategies through selection: https://en.m.wikipedia.org/wiki/R/K_selection_theory https://en.m.wikipedia.org/wiki/R/K_selection_theory
  - jdmichal 11y ago
    You're being pretty pedantic at this point. If an individual reproduces, then none of that individual's traits were sufficiently selected against. That's also not a guarantee that all their traits will carry on in new lines. There's also no guarantee that their children will be fit, due to differing traits or changing environment.

knodi123 11y ago

> Things which [...] benefit survival are not selected for Things which impact reproduction will be selected for. Things which kill you before you can finish raising a child will be most strongly selected against. Things that allow you to keep reproducing longer will be less strongly selected for. I guarantee that if there were a gene that let men and woman keep popping out babies for a century, it would be very likely to be preserved.

jdmichal 11y ago
> Things that allow you to keep reproducing longer will be less strongly selected for. No. This is the fallacy. > I guarantee that if there were a gene that let men and woman keep popping out babies for a century, it would be very likely to be preserved. It would be preserved, yes. The fallacy is that it will not be perserved in preference of lack of the gene, because there is nothing selecting against not having that gene. In other words, both lines will continue to live on, because there is nothing selecting against either of them. As long as individuals can reproduce, then their traits are not being selected against. If there are multiple variations of the traits, those will become part of the population's natural variation. Which is a good thing to have in terms of the population, because natural variation helps prevent genetic bottlenecks.
- knodi123 11y ago
  > No. This is the fallacy. I simply don't believe you. As the one making the preposterously counterintuitive claim, it's up to you to support this with facts, beyond just saying "nope, you're wrong, it's a fallacy."
  - knodi123 11y ago
    To elaborate, if Sensible Sally's female descendants all produce one child, and Fertile Myrtle's descendants all produce 10 children each, then Myrtle's genes will multiply faster, and be less vulnerable to being wiped out by the odd plague or war.
    - 11y ago

Noosterdam 11y ago

Nothing is neutral. Every activity one undertakes is at the cost of doing something else, hence "neutral" is actually negative - and would get selected against, ex hypothesi. Even things that benefit survival but don't do it strongly enough would be functionally negative, and therefore selected against. Finally, take activities that are strongly beneficial. Not doing these things will put one at a selective disadvantage against one's rivals. If you agree with the above, there is no validity at all left in your original claim: >Things which are neutral or even benefit survival are not selected for.

jdmichal 11y ago
If I understand correctly, your basic argument is something along the lines of, "Eating is obviously extremely beneficial. Therefore eating must be selected for. Therefore your statement is false." My rebuttal would be that you are looking at the wrong side of the equation. Eating is not selected for; not eating is selected against. So no, your argument does not counter my original claim. Such reworkings of the argument may seem petty, but they are centered around a deeper understanding of what exactly selection is and how it works.