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Environmental pressures are the catalyst of evolution. Pushing a species to adapt to changes therein. My question is can these mechanisms cause significant adaptation over one generation(parent-> child). My thinking is the pressure of the equivalent of human trauma in a species(depending on neurological and biochemical makeup of said species) would be enough to induce genetic influence.

If not, what is the minimum theorized timeframe for environmental pressures to act?

Edit: This is not a duplicate, the previous question is about one animal's lifetime

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marked as duplicate by kmm, anongoodnurse, David, Bryan Krause, De Novo Mar 5 at 20:03

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ I've tried to answer your question, though I am a little confused about the sentence re: "the equivalent of human trauma". $\endgroup$ – De Novo Mar 5 at 4:41
  • $\begingroup$ @DeNovo to clarify further, an event that would cause some sort of psychological ailment as a result(i.e PTSD,GAD) in humans. From what I understand, things like anxiety from social or non-threatening situations are neutered versions of the physiological reactions we had pre-society. $\endgroup$ – hisairnessag3 Mar 5 at 6:53
  • $\begingroup$ @hisairnessag3 so your point is that if parent in childhood experience some trauma ( for example sexual abuse) if that change genetic information hand over to children? Am i correct ? $\endgroup$ – L.Diago Mar 5 at 13:08
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    $\begingroup$ Don’t think that this is a duplicate as the main question (ignore speculation on trauma) can be answered with a definitive YES. This was demonstrated recently for first time: Rowan D. H. Barrett et al., “Linking a mutation to survival in wild mice.” Science 363, no. 6426. (February 1, 2019). doi: 10.1126/science.aav3824 $\endgroup$ – tsttst Mar 6 at 15:21
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    $\begingroup$ The formal link between going from environmental pressure to change in frequency of a naturally occurring variant of a gene within one generation for non-laboratory condition is new. Given everything else known about evolution and molecular mechanisms of inheritance this is expected. The above shows it explicitly within one generation. 160 years ago they did not study genes. $\endgroup$ – tsttst Mar 8 at 6:41
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Can environmental pressures affect genes in one generation?

Yes. Environmental pressures that cause a change in allele frequency will always produce changes in a single generation. If the environmental pressure is present for more than one generation, it will affect changes in allele frequency over a longer time span.

I'd encourage you to look at this set of case studies from UC Berkeley's Understanding Evolution

To clarify what "pressure" means in the context of evolution. Selective pressure, or evolutionary pressure, as wikipedia describes it, is anything that changes the reproductive success of an organism. It is, by definition, something that has an effect in one generation. Selective pressure causes organisms with certain heritable characteristics (and certain alleles) to reproduce at a different rate from organisms with other heritable characteristics (other alleles). The pressure selects for certain alleles.

Considering the comments, it sounds like you're describing a disorder (psychological ailment, e.g., PTSD, GAD), which may have a heritable diathesis, and an environment (trauma) that causes the expression of that disorder. To consider that environment to be selective pressure, it would need to be present at a population level and cause individuals with that heritable diathesis to reproduce at a different rate than individuals without it. If it did, you would see changes in allele frequency over one generation. Indeed there is no way for selective pressure to cause a change in allele frequency without it occurring in a single generation. I'm not aware of any study that has demonstrated this to be the case for any anxiety disorder.

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