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Comment by phkahler | Hacker News Reader

>> For example, your grandmother from your moms side technically made the egg cells that you were born from.

That can't be right. Grandma gave mom a single cell. Mom's ovaries with grandpa's DNA too produced the egg leading to me. Or is there some element I'm not aware of that make it more like stated above?

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Look into epigenetic inheritance. This is a mechanism by which environmental factors cause inheritable modulation of genes, which themselves are unchanged. Methylation (attachment of methyl groups) of DNA is one such mechanism.

https://en.wikipedia.org/wiki/Transgenerational_epigenetic_i...

https://www.nature.com/articles/s41437-018-0113-y

Yeah but it has absolutely no explanatory power for sociological phenomenon. People want it to be true, but there's just no there there.

https://razib.substack.com/p/you-cant-take-it-with-you-strai...

Thanks for this link, it's an interesting and informative post. Gives me an additional PoV to consider.

> Yeah but it has absolutely no explanatory power for sociological phenomenon

That's a nice broad generality, but it doesn’t seem to be true. For instance, on the specific subject of thw thread, epigenetic changes related to chronic stress have demonstrated to have evidence of both (1) some intergenerational transmissibility, and (2) a role in alcoholism.

I guess the egg cell you came from was made inside your grandma when your mom was an embryo in her. So the the cell was technically made inside your grandma’s body.

isn't the mother just providing the nourishment for the fetus to grow inside her? and the fetus itself, takes the nourishment, and actually producing the eggs inside itself?

So technically I don't think we can say the grandma is making the eggs directly, but has assisted in the fetus' creation, and then provided the nutrients/environment for the egg creation that the fetus itself makes (which yes, can influence things w/ the generational trauma science coming out...).

mom and dad also supply a half helix [single strand] of DNA, with conservation of state.

this passes on the structural features responsible for regulatory configuration

epigenetic modulation of penetrance, and/or heritability.

environment causes biochemical changes of the state of the DNA. methylation is a common phenomenon.

also, vertical transmission of DNA state facilitating transcription factor modulation of constituative expression. this one is a complex concept but is also a common example.

sums up to, physical state of DNA can be transferred and conserved, during replication.

It this stage inherited “genetic trauma” is a fringe scientific theory.

Epigenetics is not fringe science - you inherit the methylation patterns from your parents' genes. Two people with the same genes can (in principle) have very different methylation patterns & thus differences in gene expression that result in changes in behaviour.

None of this is controversial.

That’s about parent’s environmental exposure affecting gene expression in their children. The notion that this can be passed down over multiple generations, where the parent’s generation wasn’t directly exposed to the environmental conditions, is fringe.

Its not “fringe”, it is demonstrated as a thing which occurs.

Some particular multigenerational effects may be controversial, speculative, or even fringe, but that multigenerational epigenetic effects exist is not at all fringe.

Confidently asserting that there is a generalized “concept of genetic trauma” that explains behavioral phenomena, as the poster did above, is not correct. The science on this is extremely limited: https://www.bbc.com/future/article/20190326-what-is-epigenet.... And it gets invoked by non-experts to support a lot of fringe assertions.

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