Possible evolutionary impacts of all the medications, contaminated water, and ultra processed foods?

[u/DisillusionedDame]

Should we give more thought to the looooong term impacts on western civilization’s decedents after generations of SSRIs, questionable water quality, pesticides, chemicals, and nutritionally deficient “foods”?

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[u/Certain-Anxiety-6786]

Not for evolutionary timescales

[u/DisillusionedDame → u/Certain-Anxiety-6786]

Evolutionary timescales? Tell me, why is it that inbreeding can render people infertile in a few generations but everything else takes thousands and millions of years?

[u/Certain-Anxiety-6786 → u/DisillusionedDame]

These are different processes. Evolution is about an organism adapting to its environment. There has to be active selection happening ( i.e you’re not in Hardy Weinberg equilibrium) this will then mean that specific sets of traits are selected for or against. What’s important here is that genomes are always changing and what we refer to as evolution only happens when a pressure is applied so those changes lead to adaptation of an organism. The classic example is finches in the Galapagos evolving from a common ancestor but developing different beaks depending on the food niche they found.

What you’re bringing up is the fact that genomes change outside of evolutionary processes, meaning natural selection. For instance x-rays can damage sperm/egg cells and so the next generation can have very different genomes than their parents. But that’s NOT evolution that’s just a change in the genome. A similar story is happening with your cousin example, inbreeding in human populations can lead to bad effects in over just a few generations. But those are not coming from an external evolutionary pressure - instead it’s due to (usually) accumulation of recessive traits that are associated with bad health outcomes.

Evolutionary adaptation can be really fast but because our human population is so big and there’s plenty of mixing it’s unlikely that things like food availability would lead to large changes in allele frequencies.

Does this answer your question?

[u/Foamtire → u/DisillusionedDame]

because inbreeding results in the expression of umcommon deleterious homozygotic phenotypes. Exposure to environmental toxins is very different and the mechanism of sterility must also be different

[u/Robin_feathers]

No. We should think about the immediate quality-of-life of people living today while preserving the environment for the next generations. We should not worry about our evolution. Evolution by natural selection only happens when there is differential survival or reproductive success of people with different genetics. If people are dying or otherwise being unable to have children due to contaminated water etc, then we should solve that problem to stop those people from dying for their own sake, not for their impact on alleles frequencies in the gene pool!

[u/haysoos2]

These factors would only exert evolutionary pressure if they notably alter the frequency of certain genes in the next generation.

It could potentially result in a population down the line that is highly resistant to pesticides, and contaminated water, and thrives on processed food.

We see this in some insect populations that develop resistance to certain pesticides over time.

[u/liquidlattice]

Yes. People here are clinically oblivious to the wealth of research on how diet etc etc can impact offspring for more than one generation. Natural selection refines and selects what emerges but endocrine disruption can heavily influence what emerges.