Much more important than the controversy over whether "math is racist." However, I think if we step away from the topic of race, and focus on eugenics more broadly, then the topic of Mendelianism does gain more relevance. Not something to be hysterical about, but good to "teach the controversy."
I was amazed to read, via Sasha Gusev, that most genes are much more polygenic than I had imagined. For traits like alcoholism, or impulsivity, or introversion, there are so many contributing genes that eliminating those behaviors via "eugenics" becomes much more difficult than "sterilizing all the blondes to eliminate blondness."
Given my high school level of genetics knowledge, I didn't understand this, and I thought you could just "sterilize the alcoholics, to get rid of the alcoholism gene." It's more complicated than that -- polygenic traits are much more resistant to selective pressures than monogenic traits, even under strict or harsh conditions. Adding nuance and understanding is always good.
You could also use the atomic model as an example where an inaccurate heuristic is still used in the classroom. We still learn in high school that the protons, neutrons, and electrons are little bowling balls in a little solar system.
I agree. I have no objection to increasing the rigor of genetics education, though we shouldn't expect this to be some panacea against all misunderstandings.
My circuitous point here is that Mendel is the appropriate foundation to work from in genetics education relative to proposed alternatives. Also, the alleged harms of teaching Mendel aren't visible in general social attitudes as they haven't been convincingly shown even in the salient education research (the study I looked at appeared in Science Magazine's policy forum).
I also think we simultaneously underplay both the impact of single gene traits and complex traits and how these work with respect to selection pressure and it's consequences. It's difficult to actually provide a proper understanding because it's difficult to generalize when there will be exceptions, special cases, etc.
The evolutionary questions are the ones that raise more hackles (and aren't necessarily linked in curriculum to Mendel's work/can be left to student's imagination or curiosity). Your example makes an important point. The genetic architecture of different traits, the extent to which a trait is under direct genetic control, the mechanism in question, and the environment in which this all happens all have important influence over the evolutionary possibilities for many socially relevant traits. How selection has happened on complex human traits in our recent history is an open, unresolved question but it also seems like there has been meaningful amounts. You've probably heard mention of the recent Reich lab pre-print on the subject. Then there's the deep history which matters too and must have hosted important selection on social/behavioral traits.
That's another important consideration -- how a gene responsible for alcoholism could also be responsible for a seemingly unrelated but beneficial trait, and how eliminating the gene for alcoholism could have unintended consequences. And then the fact that seemingly unrelated genes can interact in complex and unexpected ways. It's sort of like playing 4-dimensional Jenga -- hard to remove blocks without causing massive butterfly effects. It's a very fragile and interconnected system. Hence why legislation against pollution is really important in my opinion.
Evolution is decent about creating a robust systems (e.g. diploidy/sexual reproduction), which is partially why so many monogenic diseases can be observed and passed on in the first place even though they come at an obvious fitness penalty. There are of course genotypes entirely incompatible with life too (what's often called embryonic lethal situations - why the miscarriage rate is an underestimate).
There are still many vulnerabilities in evolved systems, but these often have to do with tradeoffs or catastrophic events that are obviously the end of a particular lineage. There's also no guarantee current adaptive genotypes will continue to be adaptive as environments change. Perhaps this is what you mean regarding pollution, a source of unexpected environmental challenge to fitness?
I'm not sure Ive caught what you mean, but you rightly identified pleiotropy (a genotype with several different phenotypic consequences) as an important consideration when thinking about (shaping) human evolution. This is easy to communicate to lay people within a Mendelian framework, e.g. sickle trait where heterozygote carriers have resistance to malarial infection while homozygotes have sickle cell disease.
I meant literal environmental pollution -- like forever chemicals, plastics, asbestos, lead, because they can have an epigenetic effect which becomes heritable. Legislating against pollution has a more efficient impact on genetic health than laws which would interfere, incentivize, promote, or prohibit certain individuals or populations from breeding. It certainly carries less moral risks and unintended consequences. Libertarians make an economic argument against excessive environmental regulation, but I think it needs to be measured against the full economic effects of poor health, compounded intergenerationally -- since all of these problems are intergenerational.
I think we have really good reason to believe that transgenerational epigenetic inheritance (TGEI) is not a meaningful biological phenomenon. Both Kevin Mitchell (Title - "Grandma's trauma - a critical appraisal of the evidence for transgenerational epigenetic inheritance in humans") and Razib Kahn (title - You can't take it with you - https://www.razibkhan.com/p/you-cant-take-it-with-you-straight) have pretty good explainers on why this is. The short of it is that the cases where TGEI has been alleged are just explained by conventional DNA mutations being passed on. TGEI is also not consistent with what's known about the effects of fertilization on epigenetic patterns (there's essentially a factory reset).
This isn't to downplay concerns about the effect of the environment on health in the here and now though. There is certainly an important role for government in ensuring some amount of basic public health. There have been claims that some newer environmental exposures are impacting fertility, though there are number of confounding factors at play and there are other reasons to be skeptical of those claims too.
My use of the word epigenetic might not be accurate. What I mean to say is that I believe chemicals can cause meaningful damage to sperm and eggs (mutations), and this damage is heritable. This is different from saying, "I was stressed out, and so my grandson now has a genetic imprint of my stress." I'm talking about direct chemical interactions. Additionally, when sperm counts lower as a result of chemical interference, then the quality of sperm also drops, which can reduce fitness.
Specifically, I am claiming that we should begin to address genetic health by regulating chemicals which are known to cause mutations or sperm degradation, before we think about pointing to a group of people and saying, "you can't reproduce," or trying to raise the birth rates of certain other groups.
But really to have the most informed conversion, we need to get into estimates of what the chemicals with the greatest impact are; which ones affect genetic health and which ones cause non-genetic harm; probabilities of damage per exposure amount; then turn that into a healthcare cost; then compare that with the economic benefit of the chemical.
I wish the EPA already did this, so you could "sort by most damage" in a list of all known industrial chemicals, and simply tax them accordingly. The biggest frustration for me is the lack of public data which is communicated in a way that is understandable for a layman.
This is a really good way to put it: “Genetic concepts like epistasis, linkage, penetrance, and expressivity are often easier to grasp when a foundation of Mendelian genetics has been established”.
It’s the same way we teach the atomic model. We don’t jump straight to electron clouds.
Great article. I had always known about the assaults on, well, anything that doesn’t support super-egalitarianism and blank-slate theory— especially evolutionary psychology—but I hadn’t known that even Mendel had come under fire.
Much more important than the controversy over whether "math is racist." However, I think if we step away from the topic of race, and focus on eugenics more broadly, then the topic of Mendelianism does gain more relevance. Not something to be hysterical about, but good to "teach the controversy."
I was amazed to read, via Sasha Gusev, that most genes are much more polygenic than I had imagined. For traits like alcoholism, or impulsivity, or introversion, there are so many contributing genes that eliminating those behaviors via "eugenics" becomes much more difficult than "sterilizing all the blondes to eliminate blondness."
Given my high school level of genetics knowledge, I didn't understand this, and I thought you could just "sterilize the alcoholics, to get rid of the alcoholism gene." It's more complicated than that -- polygenic traits are much more resistant to selective pressures than monogenic traits, even under strict or harsh conditions. Adding nuance and understanding is always good.
You could also use the atomic model as an example where an inaccurate heuristic is still used in the classroom. We still learn in high school that the protons, neutrons, and electrons are little bowling balls in a little solar system.
I agree. I have no objection to increasing the rigor of genetics education, though we shouldn't expect this to be some panacea against all misunderstandings.
My circuitous point here is that Mendel is the appropriate foundation to work from in genetics education relative to proposed alternatives. Also, the alleged harms of teaching Mendel aren't visible in general social attitudes as they haven't been convincingly shown even in the salient education research (the study I looked at appeared in Science Magazine's policy forum).
I also think we simultaneously underplay both the impact of single gene traits and complex traits and how these work with respect to selection pressure and it's consequences. It's difficult to actually provide a proper understanding because it's difficult to generalize when there will be exceptions, special cases, etc.
The evolutionary questions are the ones that raise more hackles (and aren't necessarily linked in curriculum to Mendel's work/can be left to student's imagination or curiosity). Your example makes an important point. The genetic architecture of different traits, the extent to which a trait is under direct genetic control, the mechanism in question, and the environment in which this all happens all have important influence over the evolutionary possibilities for many socially relevant traits. How selection has happened on complex human traits in our recent history is an open, unresolved question but it also seems like there has been meaningful amounts. You've probably heard mention of the recent Reich lab pre-print on the subject. Then there's the deep history which matters too and must have hosted important selection on social/behavioral traits.
That's another important consideration -- how a gene responsible for alcoholism could also be responsible for a seemingly unrelated but beneficial trait, and how eliminating the gene for alcoholism could have unintended consequences. And then the fact that seemingly unrelated genes can interact in complex and unexpected ways. It's sort of like playing 4-dimensional Jenga -- hard to remove blocks without causing massive butterfly effects. It's a very fragile and interconnected system. Hence why legislation against pollution is really important in my opinion.
Evolution is decent about creating a robust systems (e.g. diploidy/sexual reproduction), which is partially why so many monogenic diseases can be observed and passed on in the first place even though they come at an obvious fitness penalty. There are of course genotypes entirely incompatible with life too (what's often called embryonic lethal situations - why the miscarriage rate is an underestimate).
There are still many vulnerabilities in evolved systems, but these often have to do with tradeoffs or catastrophic events that are obviously the end of a particular lineage. There's also no guarantee current adaptive genotypes will continue to be adaptive as environments change. Perhaps this is what you mean regarding pollution, a source of unexpected environmental challenge to fitness?
I'm not sure Ive caught what you mean, but you rightly identified pleiotropy (a genotype with several different phenotypic consequences) as an important consideration when thinking about (shaping) human evolution. This is easy to communicate to lay people within a Mendelian framework, e.g. sickle trait where heterozygote carriers have resistance to malarial infection while homozygotes have sickle cell disease.
I meant literal environmental pollution -- like forever chemicals, plastics, asbestos, lead, because they can have an epigenetic effect which becomes heritable. Legislating against pollution has a more efficient impact on genetic health than laws which would interfere, incentivize, promote, or prohibit certain individuals or populations from breeding. It certainly carries less moral risks and unintended consequences. Libertarians make an economic argument against excessive environmental regulation, but I think it needs to be measured against the full economic effects of poor health, compounded intergenerationally -- since all of these problems are intergenerational.
I think we have really good reason to believe that transgenerational epigenetic inheritance (TGEI) is not a meaningful biological phenomenon. Both Kevin Mitchell (Title - "Grandma's trauma - a critical appraisal of the evidence for transgenerational epigenetic inheritance in humans") and Razib Kahn (title - You can't take it with you - https://www.razibkhan.com/p/you-cant-take-it-with-you-straight) have pretty good explainers on why this is. The short of it is that the cases where TGEI has been alleged are just explained by conventional DNA mutations being passed on. TGEI is also not consistent with what's known about the effects of fertilization on epigenetic patterns (there's essentially a factory reset).
This isn't to downplay concerns about the effect of the environment on health in the here and now though. There is certainly an important role for government in ensuring some amount of basic public health. There have been claims that some newer environmental exposures are impacting fertility, though there are number of confounding factors at play and there are other reasons to be skeptical of those claims too.
My use of the word epigenetic might not be accurate. What I mean to say is that I believe chemicals can cause meaningful damage to sperm and eggs (mutations), and this damage is heritable. This is different from saying, "I was stressed out, and so my grandson now has a genetic imprint of my stress." I'm talking about direct chemical interactions. Additionally, when sperm counts lower as a result of chemical interference, then the quality of sperm also drops, which can reduce fitness.
Specifically, I am claiming that we should begin to address genetic health by regulating chemicals which are known to cause mutations or sperm degradation, before we think about pointing to a group of people and saying, "you can't reproduce," or trying to raise the birth rates of certain other groups.
But really to have the most informed conversion, we need to get into estimates of what the chemicals with the greatest impact are; which ones affect genetic health and which ones cause non-genetic harm; probabilities of damage per exposure amount; then turn that into a healthcare cost; then compare that with the economic benefit of the chemical.
I wish the EPA already did this, so you could "sort by most damage" in a list of all known industrial chemicals, and simply tax them accordingly. The biggest frustration for me is the lack of public data which is communicated in a way that is understandable for a layman.
This is a really good way to put it: “Genetic concepts like epistasis, linkage, penetrance, and expressivity are often easier to grasp when a foundation of Mendelian genetics has been established”.
It’s the same way we teach the atomic model. We don’t jump straight to electron clouds.
Thanks! I read this and many of the links. And just bought The Genetic Lottery from Audible.
Great article. I had always known about the assaults on, well, anything that doesn’t support super-egalitarianism and blank-slate theory— especially evolutionary psychology—but I hadn’t known that even Mendel had come under fire.
Solid stack. No reason to be so apologetic. No reason to bury the lede.