5 ms·

Its not just caching. This stuff seems to survive generations too by some as yet unknown magic. Google "inherited PTSD".

ghostcluster 8y ago
There is also a lot of activism masquerading as science in the field of epigenetics, enough so that the journal Cell issued a warning about it: https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4 https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4
- tim333 8y ago
  There have been interesting animal experiments which perhaps avoid that eg >Perhaps the most intriguing animal paper so far is a study published online in the winter of 2013 that appeared to show that fear memories can be inherited. Researchers from Emory University trained male mice to associate an odor with an electrical shock, so that they would get startled simply by smelling the odor by itself. Surprisingly, the scientists found that the smell also startled the next two generations of mice. https://www.vox.com/2014/8/18/5927269/epigenetics-definition-cancer-diet-explained-inheritance-DNA-methylation https://www.vox.com/2014/8/18/5927269/epigenetics-definition...
  - phkahler 8y ago
    Did they rule out learning the behavior from the parent mice?
    - goodmachine 8y ago
      This presupposes that the senior mouse, having been exposed, can describe both a particular smell and the appropriate response to a junior mouse. So I'd guess that's ruled out already.
    - klmr 8y ago
      Yes, by raising pups with surrogate parents. However, the study was criticised for other reasons (lack of statistical power, no explanatory mechanism) and, in the intervening years, nobody has successfully replicated this experiment.
peteretep 8y ago
Currently in Ubud, Bali, so being exposed to lots of hippie bullshit (crystal reiki healing, anyone?). However, there's an idea floating around alternative medicine that human families can inherit trauma, and perhaps this is a mechanism for it? Seems more likely that the effect (if any) would be passed down through socialization, but food for thought.
- alexyoung 8y ago
  Take a look at "Transgenerational epigenetic inheritance" (https://en.wikipedia.org/wiki/Transgenerational_epigenetic_inheritance https://en.wikipedia.org/wiki/Transgenerational_epigenetic_i...) and at research into how epigenetic inheritance is cited as a mechanism for passing down trauma between generations. I read about malnutrition in world war II affecting several generations but I don't remember the source, and the Wikipedia article mentions the Dutch famine
  - klmr 8y ago
    Same caveat as above: the existing studies are deeply flawed. So far, the evidence for this kind of trans-generational inheritance is very week, and there’s no plausible mechanism to explain it, either.
klmr 8y ago
No study has successfully shown that inherited PTSD actually exists in humans. The studies that purport to show so are plagued by flaws. Here’s a good write-up of the state of the field: https://www.theguardian.com/science/blog/2015/sep/11/why-im-sceptical-about-the-idea-of-genetically-inherited-trauma-epigenetics https://www.theguardian.com/science/blog/2015/sep/11/why-im-... — this is from 2015 but it’s still current. At any rate, RNA definitely doesn’t survive generations. It’s a short-lived molecule. Stable epigenetic marks modify the DNA, they don’t involve RNA (except as an intermediary).
- obelix_ 8y ago
  Well here's a Google talk from last month https://m.youtube.com/watch?v=SJSJx5slLEM https://m.youtube.com/watch?v=SJSJx5slLEM
  - klmr 8y ago
    Elizabeth Rosner isn’t a biologist, and (unintentionally, I’m sure) misrepresents the research. The majority view in the field of epigenetics is that trans-generational epigenetic inheritance of things like trauma currently lacks compelling evidence and, just as importantly, a plausible mechanism. The studies from Emory University and Mount Sinai, for instance, were widely panned (see article) for lack of controls, lack of mechanistic insight, and weak statistical analysis. What little evidence there exists shows a very narrow range of effect in model animals. I’ve co-authored one such study that specifically shows the heritability of stress in mice. I can confidently say that this only works in very specific, artificially constrained instances, the evidence is tenuous, and mechanisms are elusive. To clarify, this isn’t to say that trans-generational epigenetic inheritance doesn’t exist. Rather, we know that it does in specific circumstances (in particular in invertebrate models). But the claims by Rosner and in some of the more sensational (and flawed) papers require a big leap of faith that most scientists in the field aren’t willing to take, lacking evidence and a mechanistic explanation. What’s more, none of the scenarios described by Rosner requires trans-generational epigenetic inheritance. It’s much easier explained by social/cultural transmission. Invoking epigenetics in this context is pseudoscience.

ghostcluster 8y ago

There is also a lot of activism masquerading as science in the field of epigenetics, enough so that the journal Cell issued a warning about it: https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4 https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4

tim333 8y ago
There have been interesting animal experiments which perhaps avoid that eg >Perhaps the most intriguing animal paper so far is a study published online in the winter of 2013 that appeared to show that fear memories can be inherited. Researchers from Emory University trained male mice to associate an odor with an electrical shock, so that they would get startled simply by smelling the odor by itself. Surprisingly, the scientists found that the smell also startled the next two generations of mice. https://www.vox.com/2014/8/18/5927269/epigenetics-definition-cancer-diet-explained-inheritance-DNA-methylation https://www.vox.com/2014/8/18/5927269/epigenetics-definition...
- phkahler 8y ago
  Did they rule out learning the behavior from the parent mice?
  - goodmachine 8y ago
    This presupposes that the senior mouse, having been exposed, can describe both a particular smell and the appropriate response to a junior mouse. So I'd guess that's ruled out already.
  - klmr 8y ago
    Yes, by raising pups with surrogate parents. However, the study was criticised for other reasons (lack of statistical power, no explanatory mechanism) and, in the intervening years, nobody has successfully replicated this experiment.

peteretep 8y ago

Currently in Ubud, Bali, so being exposed to lots of hippie bullshit (crystal reiki healing, anyone?). However, there's an idea floating around alternative medicine that human families can inherit trauma, and perhaps this is a mechanism for it? Seems more likely that the effect (if any) would be passed down through socialization, but food for thought.

alexyoung 8y ago
Take a look at "Transgenerational epigenetic inheritance" (https://en.wikipedia.org/wiki/Transgenerational_epigenetic_inheritance https://en.wikipedia.org/wiki/Transgenerational_epigenetic_i...) and at research into how epigenetic inheritance is cited as a mechanism for passing down trauma between generations. I read about malnutrition in world war II affecting several generations but I don't remember the source, and the Wikipedia article mentions the Dutch famine
- klmr 8y ago
  Same caveat as above: the existing studies are deeply flawed. So far, the evidence for this kind of trans-generational inheritance is very week, and there’s no plausible mechanism to explain it, either.

klmr 8y ago

No study has successfully shown that inherited PTSD actually exists in humans. The studies that purport to show so are plagued by flaws. Here’s a good write-up of the state of the field: https://www.theguardian.com/science/blog/2015/sep/11/why-im-sceptical-about-the-idea-of-genetically-inherited-trauma-epigenetics https://www.theguardian.com/science/blog/2015/sep/11/why-im-... — this is from 2015 but it’s still current. At any rate, RNA definitely doesn’t survive generations. It’s a short-lived molecule. Stable epigenetic marks modify the DNA, they don’t involve RNA (except as an intermediary).

obelix_ 8y ago
Well here's a Google talk from last month https://m.youtube.com/watch?v=SJSJx5slLEM https://m.youtube.com/watch?v=SJSJx5slLEM
- klmr 8y ago
  Elizabeth Rosner isn’t a biologist, and (unintentionally, I’m sure) misrepresents the research. The majority view in the field of epigenetics is that trans-generational epigenetic inheritance of things like trauma currently lacks compelling evidence and, just as importantly, a plausible mechanism. The studies from Emory University and Mount Sinai, for instance, were widely panned (see article) for lack of controls, lack of mechanistic insight, and weak statistical analysis. What little evidence there exists shows a very narrow range of effect in model animals. I’ve co-authored one such study that specifically shows the heritability of stress in mice. I can confidently say that this only works in very specific, artificially constrained instances, the evidence is tenuous, and mechanisms are elusive. To clarify, this isn’t to say that trans-generational epigenetic inheritance doesn’t exist. Rather, we know that it does in specific circumstances (in particular in invertebrate models). But the claims by Rosner and in some of the more sensational (and flawed) papers require a big leap of faith that most scientists in the field aren’t willing to take, lacking evidence and a mechanistic explanation. What’s more, none of the scenarios described by Rosner requires trans-generational epigenetic inheritance. It’s much easier explained by social/cultural transmission. Invoking epigenetics in this context is pseudoscience.