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Epigenetics: The Evolution Revolution

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Re: Epigenetics: The Evolution Revolution

#11

Looks like the theory of evolution needs modifications due to epigenetics.

Not sure why this is being downvoted, but it's definitely the case that as we learn more about epigenetics, we will need to modify our understanding of evolution substantially, particularly the relationship between epigenetic expression and mutation, in which the latter can "lock in" the changes from the former and lead to more rapid speciation. Exciting stuff.

Re: Epigenetics: The Evolution Revolution

#12
post #10

Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…

> For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Can you give an example?

Don't feel the trolls. It's a racist dogwhistle.

Re: Epigenetics: The Evolution Revolution

#13

Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…

> people don't understand or accept evolution [...] For example, anyone who accepts equitable distribution of attributes across genetic variances

Even if the straw-man "everybody is totally equal" can't stand up, I think there's a good argument for:

"We have to assume everybody is equal by default,(A) because we are absolutely too ignorant and limited to determine the long-term value or trade-offs within a gene or gene-combination, (B) because some diversity is itself a collective benefit to the species, and (C) because history shows most people who claimed they had the answers were often wrong and racist."

Re: Epigenetics: The Evolution Revolution

#14

Looks like the theory of evolution needs modifications due to epigenetics.

No. Natural selection happens at the level of the phenotype not the genotype. Anyway a gene is not a piece of DNA, but a unit of heredity.

The reason why epigentics is less important in evolution is because it is unstable. If an environmental factor can shift the phenotype one way then another factor can shift it back. Most of these unstable epigenetic changes wash out in an evolutionary short time frame.

Re: Epigenetics: The Evolution Revolution

#15
"What findings have made it possible?"

Recent evidence is cited, but it's interesting to note that evidence of epigenetic effects (that were ignored as known anomalies) is ancient (of course the mechanism wasn't known.) Such as, the Hinny.

"Horses and donkeys are both equids, but their evolution diverged millions of years ago. Still, they are closely enough related that they can interbreed. But the hybrids they produce look different from each other depending on whether the mother is a horse or a donkey. If she is a horse, her baby is a mule and has very long ears. If she is a donkey, her baby is a hinny. Hinnies are rare, but they are generally smaller than mules, with shorter ears.

People have known for thousands of years that horse—donkey hybrids differ depending on which species is the mother and which the father. The process thought to be responsible for these differences—genomic imprinting—has been known for only a few decades. Genomic imprinting is an epigenetic mechanism, one of the forms of biological inheritance that operate outside the traditional Mendelian mode. Imprinting is a particularly useful model for investigating epigenetic gene regulation and is a major source of epigenetic regulation in the brain.

With genomic imprinting, DNA methylation silences some genes or gene clusters—in egg, sperm, or zygote—depending on which parent they came from. For an imprinted gene, the allele from one parent or the other is shut down and makes no product. The other allele is expressed and produces characteristic outcomes in the offspring. Thus, mom's and dad's chromosomes are not functionally the same.

Imprinting is required for normal development, although if the functioning imprinted gene is defective, as sometimes happens, the outcome can also be fatal, or at least debilitating. Some 30 serious disorders are attributed to disrupted imprinting. Some are rare, but more common afflictions, such as cancers and autism, have also been linked to genomic imprinting."

https://www.academic.oup.com/bioscience/article/61/8/588/336...

Had we cared to investigate this sort of anomaly more closely, I can't help but think that we would have discovered epigenetics decades earlier. I well remember when any such discussion was entirely inadmissable amongst biologists, and proof of one's idiocy if you raised the idea of the genetic mechanism allowing any moderation of DNA as a result of environment or experience (a possibility I did in fact raise in a letter to Jacques Monod in the seventies - only silence came back, such craziness was not worthy of a response.)

There's an interesting list of early experiments, some of which may actually have been valid, but were dismissed, here: https://en.wikipedia.org/wiki/Lamarckism#Weismann's_experime...

Re: Epigenetics: The Evolution Revolution

#16
post #13

Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…

> people don't understand or accept evolution [...] For example, anyone who accepts equitable distribution of attributes across genetic variances Even if the straw-man "everybody is totally equal" can't stand up, I think there's a good argument for: "We have to assume everybody is equal by default,(A) because we are absolutely too ignorant and limited to determine the long-term value or trade-offs within a gene or ge…

I'd add a corollary along the lines of:

"We also have extreme difficulty parsing what may be caused by (epi)genetics and what may be caused by differences in experiences or development"

Not only do we lack fine-grained data with which to make that comparison, we probably lack the epistemological capabilities and experimental infrastructure to even attempt gathering such data.

This doesn't have to be mutually exclusive with the argument(s) that population-scale difference in distribution of [whatever] have been experimentally observed. It's just that for most conceivable [whatever] with some kind of relevant social impact, we still can't assign causality with high confidence to the actual (epi)genetics themselves.

Re: Epigenetics: The Evolution Revolution

#17
post #13

Slippery slope here. Most people don't understand or accept evolution, even engineers. For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Evolution is messy. Epigenetics makes it even messier. We have to be careful not to conflate the value of someone by anything genetic. Especially not epigenetics, which seems from this article to be r…

> people don't understand or accept evolution [...] For example, anyone who accepts equitable distribution of attributes across genetic variances Even if the straw-man "everybody is totally equal" can't stand up, I think there's a good argument for: "We have to assume everybody is equal by default,(A) because we are absolutely too ignorant and limited to determine the long-term value or trade-offs within a gene or ge…

The only thing I don't like about people who deny the strong influence of genes on the individual are they tend to shout racist at anyone trying to study this question. This shouting has made whole areas of human research impossible to study in practice.

Does anyone know of anyone who became a racist because they looked at the scientific literature? My experience is people become racist for a variety of reasons and then (occasionally) draw upon a paraody of science to try and justify their beliefs.

Re: Epigenetics: The Evolution Revolution

#18
post #10

Earlier quoted context omitted.

> For example, anyone who accepts equitable distribution of attributes across genetic variances(a commonly accepted social narrative). Can you give an example?

Don't feel the trolls. It's a racist dogwhistle.

You read that comment with bad understanding or bad faith. They explicitly argue against tying (epi)genetics to evaluating someone's potential.

Whether you agree with that guidance or not, whether you agree with the implications, such data exists. Trying to wish it away contributes to the toxic hellstorm that exists in public discourse around these subjects. It retrenches the people who are curious about it and sends them into the narrative arms of the people who want to misuse it for their own social ends. It's much more productive to argue why such data is extremely limited, poorly understood and not conclusive.

Re: Epigenetics: The Evolution Revolution

#19
post #13

Earlier quoted context omitted.

> people don't understand or accept evolution [...] For example, anyone who accepts equitable distribution of attributes across genetic variances Even if the straw-man "everybody is totally equal" can't stand up, I think there's a good argument for: "We have to assume everybody is equal by default,(A) because we are absolutely too ignorant and limited to determine the long-term value or trade-offs within a gene or ge…

The only thing I don't like about people who deny the strong influence of genes on the individual are they tend to shout racist at anyone trying to study this question. This shouting has made whole areas of human research impossible to study in practice. Does anyone know of anyone who became a racist because they looked at the scientific literature? My experience is people become racist for a variety of reasons and t…

>This shouting has made whole areas of human research impossible to study in practice.

Maybe here in the West, but something tells me China isn't going to get caught up in either the ethical or political implications of such research. They'll just do it and quickly operationalize (or weaponize) whatever they discover as fast as possible.

Re: Epigenetics: The Evolution Revolution

#20
post #11

Looks like the theory of evolution needs modifications due to epigenetics.

Not sure why this is being downvoted, but it's definitely the case that as we learn more about epigenetics, we will need to modify our understanding of evolution substantially, particularly the relationship between epigenetic expression and mutation, in which the latter can "lock in" the changes from the former and lead to more rapid speciation. Exciting stuff.

I think the existing understanding of evolution is still fine. Darwin wrote,

1.More individuals are produced each generation that can survive.

2. Phenotypic variation exists among individuals and the variation is heritable.

3. Those individuals with heritable traits better suited to the environment will survive.

4. When reproductive isolation occurs new species will form.

When Darwin proposed this, he didn't have any idea of molecular genetics, let alone epigenetics. Mendel too wrote about alleles but he didn't know about base pairs of DNA. Evolution really only concerns phenotypic variation, not the underlying basis for it, so it doesn't matter if the variation is due to a genetic or epigenetic change.

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