3 ms·

Ok then... why does depression potentially lead to suicide? Is that also adaptive? (stick with me, I'm not being facetious) Consider the possibility that suici

by bentt 2y ago

Ok then... why does depression potentially lead to suicide? Is that also adaptive? (stick with me, I'm not being facetious) Consider the possibility that suicide is an adaptive response by the microbiome. After all, the microbes that colonize our body would survive (and subsequently participate in consuming the body, a process called autolysis). It might be their collective way of saying "this vessel is no longer viable, let's take our chances on the outside". Think of it as a self-destruct button and they're ejecting in the escape pods. This challenges our ideas about self.

strogonoff 2y ago
Since no individual exists standalone, we must see the individual not only as such, but also part of the larger organism/society. It is easy to see the many ways of how suicide of an individual may well be adaptive, at least historically, for the larger organism/society of which that individual is part. It may be possible to speculatively frame it such that survival of the larger system would also benefit microbes that coexist with it (by way of colonising the bodies of its members), but I would warn against literally attributing suicide to microbes—the causal relationship is far from clear (over-simplifying, a person who feels unnecessary could incur stress manifesting as impaired immune response and over-representation of particular microbes).
- Terr_ 2y ago
  So some kind of... individual apoptosis? I think that hypothesis would need more support in terms of some kind of, er, cancerous outcome being the alternative.
  - strogonoff 2y ago
    What exactly are you calling “hypothesis”? The first paragraph of my comment is just an observation, the second is a view I specifically do not hold. If you seek examples where “malfunctioning” people who harm society’s fitness survive and reproduce you can probably find those, too, but I would not take a literal comparison to apopotisis and cancer (which we do not understand nearly enough anyway) too far.
  - numpad0 2y ago
    like murder-suicides and/or dictatorships? https://en.wikipedia.org/wiki/Murder%E2%80%93suicide https://en.wikipedia.org/wiki/Murder%E2%80%93suicide
- DrScientist 2y ago
  Are you talking about group selection or kin selection? In evolution what matters is that the gene(s) frequencies increases in response to selection. It would have to be a very big kin effect to offset suicide. https://en.wikipedia.org/wiki/The_Selfish_Gene https://en.wikipedia.org/wiki/The_Selfish_Gene
  - strogonoff 2y ago
    1. As far as I know, kin selection is a subset of group selection, they are not mutually exclusive. 2. I don’t talk about either specifically. It’s a general observation. If resources are limited, it can mean that reducing the number of consumers can improve outcomes for remaining people. 3. Do you mean human genes or genes in those microorganisms from the other commenter?
    - DrScientist 2y ago
      Kin selection is specifically about shared genes in the kinship group. Group selection can include woolly thinking about 'benefit to the species' when it's simple not possible to increase the frequency of a gene in the population if it's only in the sub-population that dies.
    - mewpmewp2 2y ago
      It's interesting when thinking why there might be evolutionary reason for suicide, it could be for benefit of the group, however in modern life people like to tout that it's a selfish act. Things have changed in modern life of course.
      - strogonoff 2y ago
        Possible leftover maladaptive behavior. Or maybe it is still adaptive (for the group) in whatever indirect way. Sacrifices in the old days are speculated to be healing for society by venting certain violent impulses out. Perhaps suicide could be healing by having society take a look at itself and reconsider something, but in modern days this would not work as they are not publicised. I am intentionally adopting an extremely society-centric position, to counter-balance individual-centric position usually adopted by default. (Again, an individual literally does not exist without the society.)
- rendx 2y ago
  > The Swedish government’s report proposed that the apathetic children were from “holistic cultures,” where it is “difficult to draw boundaries between the individual’s private sphere and the collective domain.” They were sacrificing themselves for their family by losing consciousness. “Even if no direct encouragement or directive is given,” the report said, “many children raised with holistic thinking may nonetheless act according to the group’s ‘unspoken’ rules.” https://www.newyorker.com/magazine/2017/04/03/the-trauma-of-facing-deportation https://www.newyorker.com/magazine/2017/04/03/the-trauma-of-...
- strogonoff 2y ago
  I want to stress the “historically” part. In case of humans, it is certainly that. It is not adaptive for society today, resources are not that constrained in pretty much any place one might be reading this from.
- bentt 2y ago
  Here is a pretty comprehensive meta-analysis of literature around microbiome and depression. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7510518/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7510518/ "This literature review established a strong link of microbes in the gastrointestinal tract, affecting how individuals think and how the gut-brain axis serves as an essential pathway in considering the management of several mental issues and psychiatric illnesses. Although promising, gut microbiome studies have a long way to go." So yes, you are right, the causal relationship is not definite. Still, it's an interesting lens which may one day prove to be clearer.
  - strogonoff 2y ago
    The “affecting” part is questionable unless they demonstrated that gut changes thoughts and not the opposite (e.g., stress eating resulting in different microbes) or some third factor causing both.

by bentt 2y ago

strogonoff 2y ago

Since no individual exists standalone, we must see the individual not only as such, but also part of the larger organism/society. It is easy to see the many ways of how suicide of an individual may well be adaptive, at least historically, for the larger organism/society of which that individual is part. It may be possible to speculatively frame it such that survival of the larger system would also benefit microbes that coexist with it (by way of colonising the bodies of its members), but I would warn against literally attributing suicide to microbes—the causal relationship is far from clear (over-simplifying, a person who feels unnecessary could incur stress manifesting as impaired immune response and over-representation of particular microbes).

Terr_ 2y ago
So some kind of... individual apoptosis? I think that hypothesis would need more support in terms of some kind of, er, cancerous outcome being the alternative.
- strogonoff 2y ago
  What exactly are you calling “hypothesis”? The first paragraph of my comment is just an observation, the second is a view I specifically do not hold. If you seek examples where “malfunctioning” people who harm society’s fitness survive and reproduce you can probably find those, too, but I would not take a literal comparison to apopotisis and cancer (which we do not understand nearly enough anyway) too far.
- numpad0 2y ago
  like murder-suicides and/or dictatorships? https://en.wikipedia.org/wiki/Murder%E2%80%93suicide https://en.wikipedia.org/wiki/Murder%E2%80%93suicide
DrScientist 2y ago
Are you talking about group selection or kin selection? In evolution what matters is that the gene(s) frequencies increases in response to selection. It would have to be a very big kin effect to offset suicide. https://en.wikipedia.org/wiki/The_Selfish_Gene https://en.wikipedia.org/wiki/The_Selfish_Gene
- strogonoff 2y ago
  1. As far as I know, kin selection is a subset of group selection, they are not mutually exclusive. 2. I don’t talk about either specifically. It’s a general observation. If resources are limited, it can mean that reducing the number of consumers can improve outcomes for remaining people. 3. Do you mean human genes or genes in those microorganisms from the other commenter?
  - DrScientist 2y ago
    Kin selection is specifically about shared genes in the kinship group. Group selection can include woolly thinking about 'benefit to the species' when it's simple not possible to increase the frequency of a gene in the population if it's only in the sub-population that dies.
  - mewpmewp2 2y ago
    It's interesting when thinking why there might be evolutionary reason for suicide, it could be for benefit of the group, however in modern life people like to tout that it's a selfish act. Things have changed in modern life of course.
    - strogonoff 2y ago
      Possible leftover maladaptive behavior. Or maybe it is still adaptive (for the group) in whatever indirect way. Sacrifices in the old days are speculated to be healing for society by venting certain violent impulses out. Perhaps suicide could be healing by having society take a look at itself and reconsider something, but in modern days this would not work as they are not publicised. I am intentionally adopting an extremely society-centric position, to counter-balance individual-centric position usually adopted by default. (Again, an individual literally does not exist without the society.)
rendx 2y ago
> The Swedish government’s report proposed that the apathetic children were from “holistic cultures,” where it is “difficult to draw boundaries between the individual’s private sphere and the collective domain.” They were sacrificing themselves for their family by losing consciousness. “Even if no direct encouragement or directive is given,” the report said, “many children raised with holistic thinking may nonetheless act according to the group’s ‘unspoken’ rules.” https://www.newyorker.com/magazine/2017/04/03/the-trauma-of-facing-deportation https://www.newyorker.com/magazine/2017/04/03/the-trauma-of-...
strogonoff 2y ago
I want to stress the “historically” part. In case of humans, it is certainly that. It is not adaptive for society today, resources are not that constrained in pretty much any place one might be reading this from.
bentt 2y ago
Here is a pretty comprehensive meta-analysis of literature around microbiome and depression. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7510518/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7510518/ "This literature review established a strong link of microbes in the gastrointestinal tract, affecting how individuals think and how the gut-brain axis serves as an essential pathway in considering the management of several mental issues and psychiatric illnesses. Although promising, gut microbiome studies have a long way to go." So yes, you are right, the causal relationship is not definite. Still, it's an interesting lens which may one day prove to be clearer.
- strogonoff 2y ago
  The “affecting” part is questionable unless they demonstrated that gut changes thoughts and not the opposite (e.g., stress eating resulting in different microbes) or some third factor causing both.