Epigenetics in Feast, Famine: How Well Grampa Ate Could Impact Grandkids
August 27, 2013 9:27 AM Subscribe
Epigenetics (prev) is the study of changes in gene expression or cellular phenotype, caused by mechanisms other than changes in the underlying DNA sequence. David Epstein, a senior writer for Sports Illustrated has written about this topic for his book The Sports Gene (not as reductive as the title might suggest), but cut the chapter because the material he researched was so new as to require that he "caveat the writing rather heavily." Instead, he shared his chapter How an 1836 Famine Altered the Genes of Children Born Decades Later on IO9. You can read or hear more about the book in a half-hour segment from NPR's Fresh Air, opening with a story of Jennie Finch, a softball pitcher who "just whiff[ed] the best hitters in the world." (Related video clip: FSN Sport Science - Episode 7: Myths - Jennie Finch, on the force of fast baseball vs softball; ends with smarmy teaser for a "sex test")
Fascinating stuff - thanks for posting it.
posted by YAMWAK at 10:48 AM on August 27, 2013 [1 favorite]
posted by YAMWAK at 10:48 AM on August 27, 2013 [1 favorite]
There's an excellent episode of Nova on epigenetics. I believe they cover the same famine.
posted by HumanComplex at 10:52 AM on August 27, 2013 [1 favorite]
posted by HumanComplex at 10:52 AM on August 27, 2013 [1 favorite]
From the "deleted" chapter, that famine was 1) long enough ago and 2) large enough that there are plenty of people to study, and 3) there is a good control group (those who could still get food) and 4) it's an accessible population with accessible records of the past generations. I imagine there will be more interesting studies as people recognize other shared experiences (9/11 was mentioned in the chapter, as a source of shared stress).
Oh, and the transcript of that episode is fantastic. Cantankerous Neil deGrasse Tyson? Lovely! Thanks, HumanComplex!
posted by filthy light thief at 11:06 AM on August 27, 2013
Oh, and the transcript of that episode is fantastic. Cantankerous Neil deGrasse Tyson? Lovely! Thanks, HumanComplex!
posted by filthy light thief at 11:06 AM on August 27, 2013
Emotional stuff is the same, why would genes be any different? I would like to see research done on families of WWII and how this legacy has echoed into the current generations. We're not as original as we'd like to think; we are the product of outside and inside forces.
It appeared that Överkalix grandfathers were somehow passing down brief but important childhood experiences to their grandsons. Bygren knew that such a suggestion would be received by some of his peers as scientific treason. DNA sequences are passed down, experiences, after all, are supposed to die with the individual.
= Karma (kind of)
posted by St. Peepsburg at 11:10 AM on August 27, 2013
It appeared that Överkalix grandfathers were somehow passing down brief but important childhood experiences to their grandsons. Bygren knew that such a suggestion would be received by some of his peers as scientific treason. DNA sequences are passed down, experiences, after all, are supposed to die with the individual.
= Karma (kind of)
posted by St. Peepsburg at 11:10 AM on August 27, 2013
...How an 1836 Famine Altered the Genes of Children Born Decades Later on IO9.
I spent a lot of time trying to parse this before I clicked the link and finally figured it out.
posted by rocket88 at 11:18 AM on August 27, 2013 [1 favorite]
I spent a lot of time trying to parse this before I clicked the link and finally figured it out.
posted by rocket88 at 11:18 AM on August 27, 2013 [1 favorite]
Does anybody understand (who is also willing to explain) how epigenetics is different from Lamarckism? He mentioned that at the end but I didn't quite get what he was trying to say.
posted by feets at 11:31 AM on August 27, 2013
posted by feets at 11:31 AM on August 27, 2013
Does anybody understand (who is also willing to explain) how epigenetics is different from Lamarckism? He mentioned that at the end but I didn't quite get what he was trying to say.
The vastly oversimplified version is that of all the genes that you carry, only certain ones are expressed. So, as you go through life, your genetic expression changes somewhat in response to certain environmental triggers. These changes are able to be passed on to offspring.
It's not pure lamarckism - you need to have the gene being expressed and the environmental factors that precipitate that gene's expression in order to pass it on.
posted by Pogo_Fuzzybutt at 12:24 PM on August 27, 2013 [1 favorite]
The vastly oversimplified version is that of all the genes that you carry, only certain ones are expressed. So, as you go through life, your genetic expression changes somewhat in response to certain environmental triggers. These changes are able to be passed on to offspring.
It's not pure lamarckism - you need to have the gene being expressed and the environmental factors that precipitate that gene's expression in order to pass it on.
posted by Pogo_Fuzzybutt at 12:24 PM on August 27, 2013 [1 favorite]
Yeah but where do de novo mutations come from? You think cells communicate as much as they do and there is NOT environmental influence on new mutations? Some are errors, but I find it unlikely there isn't some intelligent guessing about what mutations might be beneficial given what information is available about the climate and cellular needs of the organism within it over one lifespan and those before it.
Honestly, the random mutation theory seems much more illogical to me.
I've been reading about de novo mutation and epigenetics since meeting my biological family and finding I was already living out their life stories despite having never met them.
The parallels were bizarre and matched actually LIVED experiences, not just character traits, of my biological family members. Really bizarre. Like my biological sister and I SHARE NIGHTMARES. Same themes...
I dunno, I sort of hate when people wipe out my lived experience hinting there is more that can be passed on than we currently think when the same people really aren't even reading the new research with an open mind. Lamark had sort of silly ideas, but that doesn't mean the general idea there could be more passed on in the genes and more intelligent striving for beneficial mutation, and emotional sharing and continued memory, than darwins strict random mutation/natural selection model might explain.
posted by xarnop at 4:53 PM on August 27, 2013
Honestly, the random mutation theory seems much more illogical to me.
I've been reading about de novo mutation and epigenetics since meeting my biological family and finding I was already living out their life stories despite having never met them.
The parallels were bizarre and matched actually LIVED experiences, not just character traits, of my biological family members. Really bizarre. Like my biological sister and I SHARE NIGHTMARES. Same themes...
I dunno, I sort of hate when people wipe out my lived experience hinting there is more that can be passed on than we currently think when the same people really aren't even reading the new research with an open mind. Lamark had sort of silly ideas, but that doesn't mean the general idea there could be more passed on in the genes and more intelligent striving for beneficial mutation, and emotional sharing and continued memory, than darwins strict random mutation/natural selection model might explain.
posted by xarnop at 4:53 PM on August 27, 2013
I would like to see research done on families of WWII
There has actually been a tonne of this - the most famous of which is tracking changes in descendents of those who endured the "Dutch Hunger" - the famine that occurred in Holland as a result of WWII. Fascinating stuff.
posted by smoke at 5:33 PM on August 27, 2013
There has actually been a tonne of this - the most famous of which is tracking changes in descendents of those who endured the "Dutch Hunger" - the famine that occurred in Holland as a result of WWII. Fascinating stuff.
posted by smoke at 5:33 PM on August 27, 2013
Most fascinating of all is the longitudinal research indicating a correlation between one's formative MetaFilter experiences and one's propensity to actually read the article(s)!
Anyway, I have long wondered if anyone has studied dandelion stalk height as an adaptation to low or high, or more frequent, lawn mowing -- because my anecdotal experience suggests to me that it may be. I've always considered this a potential example of natural selection, but then, I never considered epigenetic markers, either.
posted by dhartung at 1:49 AM on August 28, 2013
Anyway, I have long wondered if anyone has studied dandelion stalk height as an adaptation to low or high, or more frequent, lawn mowing -- because my anecdotal experience suggests to me that it may be. I've always considered this a potential example of natural selection, but then, I never considered epigenetic markers, either.
posted by dhartung at 1:49 AM on August 28, 2013
Yeah but where do de novo mutations come from?
A lot of mutations occur during cell division. It's pretty much impossible to perfectly replicate the entire sequence of DNA during a single division, and it's really remarkable how well our cells manage to do so with so few errors.
You think cells communicate as much as they do and there is NOT environmental influence on new mutations? Some are errors, but I find it unlikely there isn't some intelligent guessing about what mutations might be beneficial given what information is available about the climate and cellular needs of the organism within it over one lifespan and those before it.
The thing is, the mutations you're talking about here, the ones that influence later generations, are happening in a completely different cell type (i.e. the gametes) to the majority of cells that make up your body (somatic cells). Mutations do occur in somatic cells, of course, some of which can actually be beneficial to the survival of that particular cell. The result is cancer. But make no mistake, any changes that occur in your kidney or brain or spleen or liver as a result of it's interaction with the environment will not be passed on to your children. The change has to happen in the gametes (i.e. sperm and eggs).
We have actually evolved to try to keep the our reproductive cells as free from potential mutations as possible. They develop early during development and then remain more-or-less quiescent until puberty, such that they don't divide too many times during the intervening years. In females, the oocytes are basically made in a single batch in the womb and are then put aside for later, such that any mutations they contain occurred before the woman was even born! Nevertheless, despite such "measures" (one needs to be wary of inserting logic into biology; these mechanisms were not designed, they evolved), there is no doubt that the environment influences the gametes. Male spermatogenesis continues through life and accumulates errors along the way, both intrinsically (e.g. replication errors) and extrinsically (starvation, radiation) generated. As discussed in the links above.
It's a good post and an extremely interesting subject. Epigenetic regulation of gene expression influences every single aspect of our biology. It's also extremely difficult to study, particularly for those trying to bridge the genotype-phenotype divide. Even with the (relatively) recent advances in deep-sequencing, just identifying genes that are involved in complex (and often poorly defined) phenotypes is really hard, let alone determining exactly how they work. I'm not in the field myself, but I am very impressed by the way it's headed. The next decade will be an interesting one for geneticists.
posted by kisch mokusch at 5:09 AM on August 28, 2013 [3 favorites]
A lot of mutations occur during cell division. It's pretty much impossible to perfectly replicate the entire sequence of DNA during a single division, and it's really remarkable how well our cells manage to do so with so few errors.
You think cells communicate as much as they do and there is NOT environmental influence on new mutations? Some are errors, but I find it unlikely there isn't some intelligent guessing about what mutations might be beneficial given what information is available about the climate and cellular needs of the organism within it over one lifespan and those before it.
The thing is, the mutations you're talking about here, the ones that influence later generations, are happening in a completely different cell type (i.e. the gametes) to the majority of cells that make up your body (somatic cells). Mutations do occur in somatic cells, of course, some of which can actually be beneficial to the survival of that particular cell. The result is cancer. But make no mistake, any changes that occur in your kidney or brain or spleen or liver as a result of it's interaction with the environment will not be passed on to your children. The change has to happen in the gametes (i.e. sperm and eggs).
We have actually evolved to try to keep the our reproductive cells as free from potential mutations as possible. They develop early during development and then remain more-or-less quiescent until puberty, such that they don't divide too many times during the intervening years. In females, the oocytes are basically made in a single batch in the womb and are then put aside for later, such that any mutations they contain occurred before the woman was even born! Nevertheless, despite such "measures" (one needs to be wary of inserting logic into biology; these mechanisms were not designed, they evolved), there is no doubt that the environment influences the gametes. Male spermatogenesis continues through life and accumulates errors along the way, both intrinsically (e.g. replication errors) and extrinsically (starvation, radiation) generated. As discussed in the links above.
It's a good post and an extremely interesting subject. Epigenetic regulation of gene expression influences every single aspect of our biology. It's also extremely difficult to study, particularly for those trying to bridge the genotype-phenotype divide. Even with the (relatively) recent advances in deep-sequencing, just identifying genes that are involved in complex (and often poorly defined) phenotypes is really hard, let alone determining exactly how they work. I'm not in the field myself, but I am very impressed by the way it's headed. The next decade will be an interesting one for geneticists.
posted by kisch mokusch at 5:09 AM on August 28, 2013 [3 favorites]
We Still Don’t Know Why We Look Like Our Parents: Genetics? Sure, but it’s not that simple.
posted by homunculus at 9:52 AM on August 28, 2013
posted by homunculus at 9:52 AM on August 28, 2013
« Older Vermont Yankee nuclear plant announces closure | Clarence B Jones, wiretapping and Dr Martin Luther... Newer »
This thread has been archived and is closed to new comments
Doesn't seem to have hurt these guys.
posted by The 10th Regiment of Foot at 10:45 AM on August 27, 2013