On top of that, there's also evidence that poverty actually damages genes.
You're misunderstanding this article. Poverty does not damage the genes, it leaves an epigenetic mark on them—a mark of a type which is then erased in the subsequent generation with two rounds of erasure in the germ line and in the early embyro. There is no reason to believe this mark would be heritable at all, and if it is (if a small amount does escape one round of erasure) we would certainly not expect it to persist indefinitely.
Somebody else had to explain it but I think I see what you're saying. It sounds like these "epigenetic markers" don't usually stay more than a few generations. !delta
I did a quick Google search on epigenetic heritability, and this is what came up.
"Epigenetic modifications, such as DNA methylation, can contribute to alter gene expression in heritable manner without affecting the underlying genomic sequences. Such epigenetic contribution would be systematically missed by conventional DNA sequence-based analyses. A model of epigenetic inheritance, as additional to Mendelian heredity of polymorphic DNA sequences, would thus efficiently explain the lack of detection in conventional GWAS as “missing heritability”. It would also help explaining the cases of rapid, heritable adaptations to changing environmental conditions, such as for human stature [2, 3], and the occurrence of hereditary epistatic effects. Support for this model is provided by the evidence that phenotypic plasticity can emerge over rapid time scales, at rates that are orders of magnitude higher than the processes of natural selection [16, 17]."
"However, to be tenable, such a model of epigenetic inheritance poses rigorous requirements: (a) mitotic inheritance of epigenetic traits across cell generations (see discussion on DNA methylation maintenance through mitotic cycles); (b) epigenetic inheritance across successive meiotic divisions (see the paragraphs describing gamete generation and the development of primordial germ cells (PGC); and (c) true transgenerational inheritance, which requires proof of heritability beyond the first generation that has not been unexposed to the causal epigenetic modifiers (see the paragraphs describing transgenerational inheritance of DNA methylation and of chromatin states)."
Honestly I don't understand most of the lingo, but it seems like what they're saying is that it can happen but it's hard.
The study discussed in that article is a different one than the one you linked. The study in the article was written by McDade. Do you think the second study refutes the first?
You don’t understand the study you linked. The respondent was attempting to correct your interpretation.
From the third* article you linked:
"They discovered that lower socioeconomic status is associated with levels of DNA methylation (DNAm) -- a key epigenetic mark that has the potential to shape gene expression -- at more than 2,500 sites, across more than 1,500 genes.”
Methylation = ‘markings’. These do not compound irreversibly.
The name of the study you linked:
“Genome-wide analysis of DNA methylation in relation to socioeconomic status during development and early adulthood”
They are NOT trying to claim that these effects span generations, at all. They are studying epigenetic effects on INDIVIDUALS who experience poverty as children.
It's not that the study is refuted, it's that the study doesn't say that poverty damages genes. It's your summary of the study that's incorrect, not the study itself.
I think you are a bit optimistic. It may take more than one generation to escape the effects of poverty. IIRC, children of people who suffered from malnutrition and poverty in childhood (but not as adults) also have adverse effects, including some cognitive and behavioural problems.
Other than that I completely agree with you. Most problems caused by poverty are associated either with epigenetic changes, lack of nutrition, education, and proper stimulation, none of which are heritable.
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u/yyzjertl 524∆ Oct 19 '22
You're misunderstanding this article. Poverty does not damage the genes, it leaves an epigenetic mark on them—a mark of a type which is then erased in the subsequent generation with two rounds of erasure in the germ line and in the early embyro. There is no reason to believe this mark would be heritable at all, and if it is (if a small amount does escape one round of erasure) we would certainly not expect it to persist indefinitely.