8 ms·

Cultural differences may leave their mark on DNA

88 points by upen 10y ago

tristor 10y ago
Looks like the TL;DR conclusion is that "race" is not just a social construct, but actually has genetic markers which are expressed beyond ethnic heritage. As the authors conclude, this could be extremely important in tailoring medical treatments for people for differences in their genetic makeup based on their race. In other words harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements once again.
- winter_blue 10y ago
  Actually the genetic differences between races are far smaller and more blurry than most people would imagine (based on differences in appearance). The Atlantic had an article about exactly the kind of thing you're taking about, and how this kind of pseudoscience is being pushed by neo-nazis and the alt-right: http://www.theatlantic.com/amp/article/510962/ http://www.theatlantic.com/amp/article/510962/
  - tristor 10y ago
    Thanks for once again proving that nobody can ever have a serious discussion about science related to ethnicity because someone will always jump up, point at them, and scream "racist". I wonder if it's occurred to you how many people suffer from medical conditions because they're either untreated or treated poorly because we don't bother studying and reporting on things like this, specifically and exactly because there's a hundred people just waiting in the wings to call you a racist for studying it? Nothing in the article is racist, nor is anything in my statements. Please take your ad hominem elsewhere.
    - openasocket 10y ago
      I think he's responding to the line "harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements" which I would consider false. The existence of genetic diseases that are largely present in a single race has been known for a long time. Tay-Sachs is seen almost entirely in Ashkenazi Jews, Sickle Cell is mostly seen in Africans, etc. I don't think "identity politics" is rejecting this notion, or if it is it's doing a bad job of it.
    - tossaccttu78 10y ago
      > I wonder if it's occurred to you how many people suffer from medical conditions because they're either untreated or treated poorly because we don't bother studying and reporting on things like this, specifically and exactly because there's a hundred people just waiting in the wings to call you a racist for studying it? How will that solve for people of mixed heritage? Grandkids of mixed ancestry may look "white" (redheaded whitey here, with great-grandparents that are very obviously native american) and still have genetic predispositions passed down. The solution is not to clump by skin color. But to assess individuals specifically for certain markers. Please take your strawman elsewhere.
    - notahacker 10y ago
      To be honest, it's equally difficult to have a serious discussion about science related to ethnicity when people insist on using an interesting piece of research as a launchpad to make tangential and evidence-free claims that social science is harming serious research, regardless of whether they actually harbour any sympathy for the viewpoints of your garden variety racist or not. At the time of this article only two of the many subthreads related to this article had descended into politics and name-calling. One was initiated by your very own unsubstantiated attack on "identity politics". The other (considerably less favourably-received) post was claimed the notion of a social element to race that was the work of "lunatics and agitators seeking to attack and disrupt western society" and argued the researchers were doing themselves and society a disservice by engaging with it. Remind me who it was that's putting a negative slant on useful medical research again.
      - tristor 10y ago
        I'll admit my snipe at the end about identity politics was inflammatory, but it's specifically because of my frustrations trying to have any sort of serious discussion about these types of topics. People immediately throwing out the racist card and comparing you to neo-nazis for wanting to discuss the topic is /exactly/ what I mean by "identity politics" although its just one of the more pernicious subsets. My attack on "identity politics" is substantiated by my own experiences and a significant body of philosophical work, but probably this is not the appropriate forum for it. As a side note, when I started my thread there were more than 60 upvotes on the article and no comments. At least there's a discussion.
- WikipediasBad 10y ago
  How did you come up with that? Did you even understand the article? It is quite literally saying social/cultural changes leave an impact on genetic transcription of DNA through methylation and epigenetic markup. In fact, this proves just the opposite. That social factors are intricately tied to genetic output. What this proves false are the hardliners of each side of the debate that espouse race is a purely social construct, and the other end that naively call race a simple set of genetic traits.
  - tristor 10y ago
    I am not a geneticist, so perhaps I misunderstand, but the conclusion I formed seems to be reinforced by the quotes from the authors in the article. That is, there are specific gene expressions which are relevant in a medical context affected by cultural factors that are genetically transmitted. Genetic transmission at least to me implies that a person receives these things from their parents at birth, regardless of their own specific upbringing, because of cultural factors of their parents upbringing, and so on. As in, cultural differences can be expressed over time as genetic differences. “These data suggest that the interplay between race and ethnicity as social constructs and genetic ancestry as a biological construct is more complex than we had realized,” said Noah Zaitlen, PhD, a UCSF assistant professor of medicine and co-senior author on the new study. “In a medical context both elements may provide valuable information.” Setting aside the fact that this is such a touchy issue that the authors are carefully couching their language, it looks like there may be ways in which this new information can help people by tailoring medical treatments. I'd love a ELI5 explanation of this if I'm somehow misunderstanding, but the conclusion I formed seems to be supported by the article to my reading of it. Note, I'm not taking a hardline stance. That's why I said "race is not just a social construct" in my conclusion.
    - openasocket 10y ago
      Gene expression is partially inherited and partially a product of environment. See https://en.wikipedia.org/wiki/Transgenerational_epigenetic_inheritance https://en.wikipedia.org/wiki/Transgenerational_epigenetic_i... The classic example discussed is a study of children born during a famine. Children born during famine are going to be smaller than normal, but it was found that their children and grandchildren would be born smaller than normal, even though the famine has long since passed. This change has been attributed to a particular methylation pattern that was passed down. It's known that things like exposure to famine and abuse can change methylation patterns, but this study suggests that non-traumatic things like your cultural upbringing can affect methylation.
- hx87 10y ago
  Biological populations certainly do exist, it's just that they don't correlate well with prevailing concepts of "race". The average western African is more similar to the average European than to the average southern African.
  - erispoe 10y ago
    Populations in Africa are also genetically more diverse than the rest of the world combined.
    - lacampbell 10y ago
      But people are ignorant of Africa in general. When they talk about an African race they're ignoring Ethiopians or khoisans or pygmies - they mean Bantu people. I don't think there's more genetic diversity among Bantus than the rest of the world combined.
      - hx87 10y ago
        > But people are ignorant of Africa in general. Not population geneticists. Africa in those cases == sub-Saharan African people, not just Bantu.
  - cb18 10y ago
    Biological populations certainly do exist, it's just that they don't correlate well with prevailing concepts of "race". The average western African is more similar to the average European than to the average southern African. Absolute, utter hogwash.
    - hx87 10y ago
      Please elaborate or hold your peace.
  - lacampbell 10y ago
    Source? By southern African do you mean Khoisan?
- 4rtemis 10y ago
  I feel like biological populations can be reduced down to one individual and up to all of humanity. You can attempt to make logical decisions about where to draw these lines in between, but you'll get overlapping populations at different levels given different traits. These epigenetic flags are not dissimilar to genetic traits in that no one, nor group of them unequivocally define an individual into a biological group except if that group is "organisms that express this trait". It definitely won't square cleanly with our social macro-constructions around "race".
- samudrin 10y ago
  Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
- samudrin 10y ago
  Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
- samudrin 10y ago
  Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
- ChemicalWarfare 10y ago
  "Race" has 2 meanings. 1. Race as a social construct. It does exist in that capacity - as an extreme example Irish were not considered "white" in America (google for some "hilarious" images from "back in the day"). 2. Race as a biological reality. This is a touchy subject for a variety of reasons. But that doesn't mean that well documented taxonomic differences between human races are "fake". They do exist and are more than "skin deep" - things like bone density, cranial capacity, maturation etc etc. Ask your dentist if he can tell by looking at someone's jaw x-ray whether it belongs to an east asian or sub-saharan african.
  - svachalek 10y ago
    What I understand of the issue is that genetic differences between populations are real, but they form a continuum whose boundaries are extremely blurry if visible at all from a genetic level. Thus the drawing of boundary lines and the assignment of individuals into those handful of categories is something subject to change from culture to culture. In other words, genetic differences do not make race a "biological reality".
    - wnoise 10y ago
      They're not visible at the level of looking at one SNP at a time. If you look at a whole lot of genes, you can get a very good idea of race.
    - fvdessen 10y ago
      If you do a clustering analysis on a large sample of DNA data you will get different clusters corresponding to the usual definitions of races or ethnicities, depending on the number of clusters you choose. https://en.wikipedia.org/wiki/Human_genetic_clustering https://en.wikipedia.org/wiki/Human_genetic_clustering
      - openasocket 10y ago
        That wiki page has a pretty substantial "Criticism" section. The Rosenberg et. al. paper even says their paper "should not be taken as evidence of our support of any particular concept of biological race." Their study shows that genetic distance is roughly linear with physical distance, barring obstacles like mountains and oceans. The consensus in the field, based on citations on that wiki page, seems to be that human diversity is a continuum, so any dividing lines you try to make to partition it will be largely arbitrary. It's like looking at a rainbow at trying to divide up the yellow from the orange from the red and so on: you can do that, but your color categories don't completely capture the spectrum visible.
- stcredzero 10y ago
  Looks like the TL;DR conclusion is that "race" is not just a social construct, but actually has genetic markers which are expressed beyond ethnic heritage. That's not how I read it. My takeaway was that "race" is a social construct that can leave epigenetic markers. In other words, culture can affect physiology. In other words harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements once again. I would agree that many in the social sciences create epistemological problems for ideological reasons.
- alistproducer2 10y ago
  It's pretty clear you skimmed the article and read from it what you wanted, instead of what it actually said. I read through the responses and you've been pretty thoroughly proven wrong so I won't reiterate the points. Constructively, try not to see news as a chance to reinforce your existing views. Try and do the opposite. try to expand your world view.
deleted 10y ago
[deleted]
EekSnakePond 10y ago
ITT: San Francisco violently denies the importance of race for bone marrow transplants.
tiatia 10y ago
"conclusion is that "race" is not just a social construct" I mean, come on. This is news? What was he thinking were the different crime rates come from?
- sctb 10y ago
  This is not a great comment for HN because it's no-information flamebait. Those kinds of posts are off-topic here. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
lngnmn 10y ago
Cultural changes rate are too infinitesimal compared to the time which is required for any genetic change to get a chance to form and propagate through a population to attain a stable presence (forming a distinct trait). The probability that a certain cultural difference induced mutation could be formed (given that there is no flow of information from a phenotype back to genotype) is something incalculable. What might work for a bacteria does not work for humans due to, you see, fundamental differences in the reproductive system and development. There are a few main principles from genetics 101 to consider before making any attempts of "doing science". 1. all mutations are *random* 2. there is no backward flow of information 3. environment does not alter DNA. random mutations do 4. propagating of a mutation is an extremely rare event 5. it takes *many* generations. To understand these principles think why we do not have much mutations of, say, hemoglobin or glucose pathway enzimes. There is another fundamental principle: way to many hipsters in what they call "modern science".
- danharaj 10y ago
  The article talks about gene expression, which is much more fluid. Another factor that influences gene expression whose effects are just starting to be measured is poverty.
  - lngnmn 10y ago
    Gene expression has nothing to do with altering DNA, leave alone any propagation of such "changes".
    - danharaj 10y ago
      > The study examined DNA methylation—an “annotation” of DNA that alters gene expression without changing the genomic sequence itself—in a group of diverse Latino children. Methylation is one type of “epigenetic mark” that previous research has shown can be either inherited or altered by life experience. What are you even arguing against?
      - 10y ago
cb18 10y ago
While this article isn't entirely, reality denying non-sense, in fact mostly the opposite. The researchers do themselves and their readers huge a huge disservice with notions like, “These data suggest that the interplay between race and ethnicity as social constructs and genetic ancestry as a biological construct is more complex than we had realized, Putting forth these notions makes study and understanding of genetics far more convoluted and difficult than it needs to be. Race is ancestry, ancestry is race, plain and simple. Race is ancestry, ancestry is relatedness. Ancestry is the factor of relatedness, relatedness is the factor of race. For example an Englishman has a relatedness factor to a Dane that is hundreds of times greater than than the relatedness factor the Englishman has to a Nigerian. An Englishman and a Dane are of the European race, a Nigerian is of the (sub-Saharan) African race. You'd think this would be the simplest thing in the world to understand, but something about the modern world has caused otherwise for some people. Races are simply large extended families that came about due to imposing natural barriers in the ancient world, deserts, oceans, mountain ranges. "Social constructs" are claptrap that came about from nihilist "post-modernists," and "critical theory" lunatics and agitators seeking to attack and disrupt western society.
- danharaj 10y ago
  The construction of whiteness as an ideology of European imperial powers is well documented and well studied. I doubt you've ever read any scholarship on the matter.
  - dqv 10y ago
    Okay. I mean... You're the one saying it's well documented and well studied. Are you going to prove your assertion?
    - danharaj 10y ago
      If someone were on Hacker News trying to insist that they had violated the laws of thermodynamics or invented a perpetual motion machine, I would not be called upon to prove those laws. Race is a crank theory. It is a most pernicious crank theory because it is tied with some of the greatest brutality the world has ever seen. You have the Internet. Go use it. It is preposterous to give racists the benefit of the doubt and put the burden on us to bring up the same arguments over and over again to refute them.
known 10y ago
"Diversity society will fail" --Putnam; http://www.boston.com/news/globe/ideas/articles/2007/08/05/the_downside_of_diversity/ http://www.boston.com/news/globe/ideas/articles/2007/08/05/t...
- sctb 10y ago
  We asked you to please stop in response to this exact comment just over a month ago. Drive-by posts like this are not what Hacker News is for. We have to ban accounts that refuse to comment civilly and substantively.
kingkawn 10y ago
if culture impacts DNA then the concept of DNA being subject to mutation as the primary driving factor is at last beginning to crumble. Also if culture impacts genetics then the idea there are races is clearly not the case, but rather loosely organized behavioral groups that can change in whatever direction their common culture takes them next. All of the conclusions being drawn about the implications of this for your hobby-grudges about politics are beyond inane
pc2g4d 10y ago
In my understanding, the article was saying that who your ancestors are has less of an impact on DNA methylation (epigenetic markers) than where you grew up. It's not about race, it's about ethnicity---the cultural identity of the individuals, the environment they lived in. It's not about DNA, it's about how DNA is actually manifested, as represented by methylation markers.
- fvdessen 10y ago
  The articles states that at least 76% of the observed differences in the population come from their raw DNA. Epigenetics may thus affect up to 24% of the observed differences. So DNA is still the predominant factor.
  - medymed 10y ago
    Don't think so, they didn't look at raw dna sequences. They appear to just look at ethnicities, within which there is a lot of genetic variation.
toufka 10y ago
I'll quote myself from a previous comment regarding epigenetics. Epigenetics. It's the make-file for your genetic source code. Certain conditions can cause certain parts of your genetic code to be uncommented or commented-out. There are actually a number of different kinds of comments (histone modifications [1]) - each set of marks particular to a different compiler, in different contexts. And these comments/marks are copied with some fidelity to daughter-cells/children along with a high-fidelty copy of the underlying genetic code itself. So the genes themselves are not being heritably altered, rather the recipe for which gene is where, when can be subtly changed. But again, the same mechanisms that permit the change in expression of those genes during a lifetime can be subsequently changed in the next just as easily. In this way you can store the code for some trait or capability over many generations without having it always be running. It can manifest itself in individual organisms as having very different phenotypes even with the same underlying code. [1] https://en.wikipedia.org/wiki/Histone_code https://en.wikipedia.org/wiki/Histone_code
- marxidad 10y ago
  What muscles do you have to flex that will eventually lead to methylation of histones?
  - toufka 10y ago
    LOTS of things affect epigenetics. It currently appears to be a messy, relatively non-deterministic process with lots of different pathways crossing wires with lots of other different pathways. A snapshot of my mental model of epigenetics (warning: epigenetics/histone modifications are not my particular field of study): "The methylator slides along DNA to methylate histone tails at location 32 of histone 2 while in simultaneous competition the demethylator demethylates methyl groups of histone 1 at locations 4, 12 and 18 under most conditions, or location 32 of histone 2 IFF it is within three histones of an acetylated histone which itself has its acetylation competing with a deacetylator - constantly. And if a certain set of marks occur appropriately in combination, a set of neighboring histones wrap up and hide themselves and their DNA - preventing its hidden DNA from being used in that cell until some other mechanism can unwrap that section. Oh, and (most of) those marks are copied to children/daughter cells right along with the copying of DNA." Because it's so fickle, non-deterministic, and tangled (unlike it's DNA counterpart) it's actually pretty hard to study and is currently (like this afternoon, down your street) a topic of a significant amount of cutting edge research. As the wikipedia article above shows, the 'Histone Code' is still a work in progress, and it now appears unlikely that there is a 1:1 relationship between this chemical mark and that effect, very much unlike the very nice deterministic relationship we found between DNA->RNA->Protein. One common change I've read about that bubbles up to normal life is the capability of nicotine to affect histone acetylation. It seems to rapidly alter histone modifications so as to make other habits/actions more addictive [1] (precisely in a way that we now know THC does not - the original 'gateway drug' mis-extrapolation). [1] https://www.nih.gov/news-events/nih-research-matters/why-nicotine-gateway-drug https://www.nih.gov/news-events/nih-research-matters/why-nic...
mcjon77 10y ago
One thing that I don't hear talked about in many of these discussions about the genetic components of race is how the mixed racial ancestry of many "black" people in Europe and the Americas impacts these studies. MANY blacks in the Americas and Europe have significant European DNA. For example, even though my family identifies as black, my mother and her siblings are almost 50℅ European according to DNA tests. How does this factor in when making medical decisions based on assumptions regarding race?
- LordKano 10y ago
  As I remember it, something like 80% of people who we identify as African Americans(or black) have significant amounts of European ancestry. Outside of Africa, that's probably to be expected. I too am "black", with two "black" parents but my mother had red hair and green eyes. My son has blonde hair and blue eyes.
- macawfish 10y ago
  Unfortunately, western medical practitioners and researchers often aren't aware of the complexities of race and racial identity. I spoke with my cousin recently (who is almost done with his pharmacy PhD) and was flabbergasted at how ignorant he was about race as a social, cultural and spiritual phenomenon. Yet he casually spoke of race as a simple demographic category with genetic basis. He'd never heard of "epigenetics", though when I explained it to him, he admitted that it was a plausible idea. Racial identity translates very poorly into actual population genetics, let alone epigenetics.
kenjackson 10y ago
"Scientists and clinicians have increasingly tried to move away from simplistic racial and ethnic categories in disease research, the authors say, and – with the rise of precision medicine – in clinical diagnosis and treatment as well. Studies by the Burchard group and others have found that using genetic ancestry rather than ethnic self-identification significantly improves diagnostic accuracy for certain diseases. But the new data showing that a large fraction of epigenetic signatures of ethnicity reflect something other than ancestry suggests that abandoning the idea of race and ethnicity altogether could sacrifice a lot of valuable information about the drivers of differences in health and disease between different communities." The study shows that abandoning the idea of ethnicity could sacrifice information, but it still seems to indicate that genetic ancestry is more useful than race. Why does the article seem to conflate the two?
nickeleres 10y ago
Ugh, the alt-right supremacists are going to have a field day with mis-information around this o_o
macawfish 10y ago
You know what's crazy? My cousin is months away from finishing his PhD in pharmacy. Over thanksgiving break, he revealed to me that he had never heard the term "epigenetics". I explained it to him. He works for a drug company modeling interactions for new animal antibiotics and he'd never heard the term "epigenetics" My cousin is a bright, driven guy. There are reasons I distrust the western medical establishment.
- JamesBarney 10y ago
  The other way to look at it is epigenetics is much more important to pop-science than real science.

88 points by upen 10y ago

Looks like the TL;DR conclusion is that "race" is not just a social construct, but actually has genetic markers which are expressed beyond ethnic heritage. As the authors conclude, this could be extremely important in tailoring medical treatments for people for differences in their genetic makeup based on their race. In other words harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements once again.

winter_blue 10y ago
Actually the genetic differences between races are far smaller and more blurry than most people would imagine (based on differences in appearance). The Atlantic had an article about exactly the kind of thing you're taking about, and how this kind of pseudoscience is being pushed by neo-nazis and the alt-right: http://www.theatlantic.com/amp/article/510962/ http://www.theatlantic.com/amp/article/510962/
- tristor 10y ago
  Thanks for once again proving that nobody can ever have a serious discussion about science related to ethnicity because someone will always jump up, point at them, and scream "racist". I wonder if it's occurred to you how many people suffer from medical conditions because they're either untreated or treated poorly because we don't bother studying and reporting on things like this, specifically and exactly because there's a hundred people just waiting in the wings to call you a racist for studying it? Nothing in the article is racist, nor is anything in my statements. Please take your ad hominem elsewhere.
  - openasocket 10y ago
    I think he's responding to the line "harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements" which I would consider false. The existence of genetic diseases that are largely present in a single race has been known for a long time. Tay-Sachs is seen almost entirely in Ashkenazi Jews, Sickle Cell is mostly seen in Africans, etc. I don't think "identity politics" is rejecting this notion, or if it is it's doing a bad job of it.
  - tossaccttu78 10y ago
    > I wonder if it's occurred to you how many people suffer from medical conditions because they're either untreated or treated poorly because we don't bother studying and reporting on things like this, specifically and exactly because there's a hundred people just waiting in the wings to call you a racist for studying it? How will that solve for people of mixed heritage? Grandkids of mixed ancestry may look "white" (redheaded whitey here, with great-grandparents that are very obviously native american) and still have genetic predispositions passed down. The solution is not to clump by skin color. But to assess individuals specifically for certain markers. Please take your strawman elsewhere.
  - notahacker 10y ago
    To be honest, it's equally difficult to have a serious discussion about science related to ethnicity when people insist on using an interesting piece of research as a launchpad to make tangential and evidence-free claims that social science is harming serious research, regardless of whether they actually harbour any sympathy for the viewpoints of your garden variety racist or not. At the time of this article only two of the many subthreads related to this article had descended into politics and name-calling. One was initiated by your very own unsubstantiated attack on "identity politics". The other (considerably less favourably-received) post was claimed the notion of a social element to race that was the work of "lunatics and agitators seeking to attack and disrupt western society" and argued the researchers were doing themselves and society a disservice by engaging with it. Remind me who it was that's putting a negative slant on useful medical research again.
    - tristor 10y ago
      I'll admit my snipe at the end about identity politics was inflammatory, but it's specifically because of my frustrations trying to have any sort of serious discussion about these types of topics. People immediately throwing out the racist card and comparing you to neo-nazis for wanting to discuss the topic is /exactly/ what I mean by "identity politics" although its just one of the more pernicious subsets. My attack on "identity politics" is substantiated by my own experiences and a significant body of philosophical work, but probably this is not the appropriate forum for it. As a side note, when I started my thread there were more than 60 upvotes on the article and no comments. At least there's a discussion.
WikipediasBad 10y ago
How did you come up with that? Did you even understand the article? It is quite literally saying social/cultural changes leave an impact on genetic transcription of DNA through methylation and epigenetic markup. In fact, this proves just the opposite. That social factors are intricately tied to genetic output. What this proves false are the hardliners of each side of the debate that espouse race is a purely social construct, and the other end that naively call race a simple set of genetic traits.
- tristor 10y ago
  I am not a geneticist, so perhaps I misunderstand, but the conclusion I formed seems to be reinforced by the quotes from the authors in the article. That is, there are specific gene expressions which are relevant in a medical context affected by cultural factors that are genetically transmitted. Genetic transmission at least to me implies that a person receives these things from their parents at birth, regardless of their own specific upbringing, because of cultural factors of their parents upbringing, and so on. As in, cultural differences can be expressed over time as genetic differences. “These data suggest that the interplay between race and ethnicity as social constructs and genetic ancestry as a biological construct is more complex than we had realized,” said Noah Zaitlen, PhD, a UCSF assistant professor of medicine and co-senior author on the new study. “In a medical context both elements may provide valuable information.” Setting aside the fact that this is such a touchy issue that the authors are carefully couching their language, it looks like there may be ways in which this new information can help people by tailoring medical treatments. I'd love a ELI5 explanation of this if I'm somehow misunderstanding, but the conclusion I formed seems to be supported by the article to my reading of it. Note, I'm not taking a hardline stance. That's why I said "race is not just a social construct" in my conclusion.
  - openasocket 10y ago
    Gene expression is partially inherited and partially a product of environment. See https://en.wikipedia.org/wiki/Transgenerational_epigenetic_inheritance https://en.wikipedia.org/wiki/Transgenerational_epigenetic_i... The classic example discussed is a study of children born during a famine. Children born during famine are going to be smaller than normal, but it was found that their children and grandchildren would be born smaller than normal, even though the famine has long since passed. This change has been attributed to a particular methylation pattern that was passed down. It's known that things like exposure to famine and abuse can change methylation patterns, but this study suggests that non-traumatic things like your cultural upbringing can affect methylation.
hx87 10y ago
Biological populations certainly do exist, it's just that they don't correlate well with prevailing concepts of "race". The average western African is more similar to the average European than to the average southern African.
- erispoe 10y ago
  Populations in Africa are also genetically more diverse than the rest of the world combined.
  - lacampbell 10y ago
    But people are ignorant of Africa in general. When they talk about an African race they're ignoring Ethiopians or khoisans or pygmies - they mean Bantu people. I don't think there's more genetic diversity among Bantus than the rest of the world combined.
    - hx87 10y ago
      > But people are ignorant of Africa in general. Not population geneticists. Africa in those cases == sub-Saharan African people, not just Bantu.
- cb18 10y ago
  Biological populations certainly do exist, it's just that they don't correlate well with prevailing concepts of "race". The average western African is more similar to the average European than to the average southern African. Absolute, utter hogwash.
  - hx87 10y ago
    Please elaborate or hold your peace.
- lacampbell 10y ago
  Source? By southern African do you mean Khoisan?
4rtemis 10y ago
I feel like biological populations can be reduced down to one individual and up to all of humanity. You can attempt to make logical decisions about where to draw these lines in between, but you'll get overlapping populations at different levels given different traits. These epigenetic flags are not dissimilar to genetic traits in that no one, nor group of them unequivocally define an individual into a biological group except if that group is "organisms that express this trait". It definitely won't square cleanly with our social macro-constructions around "race".
samudrin 10y ago
Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
samudrin 10y ago
Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
samudrin 10y ago
Actually my read was that environment can influence epigenetic markers, and that environment is measureable in aggregate based on ethnicity - in this study. The study does not compare other groupings of people who share a common environment and the influence on their epigenetic markers. It says nothing about identity politics.
ChemicalWarfare 10y ago
"Race" has 2 meanings. 1. Race as a social construct. It does exist in that capacity - as an extreme example Irish were not considered "white" in America (google for some "hilarious" images from "back in the day"). 2. Race as a biological reality. This is a touchy subject for a variety of reasons. But that doesn't mean that well documented taxonomic differences between human races are "fake". They do exist and are more than "skin deep" - things like bone density, cranial capacity, maturation etc etc. Ask your dentist if he can tell by looking at someone's jaw x-ray whether it belongs to an east asian or sub-saharan african.
- svachalek 10y ago
  What I understand of the issue is that genetic differences between populations are real, but they form a continuum whose boundaries are extremely blurry if visible at all from a genetic level. Thus the drawing of boundary lines and the assignment of individuals into those handful of categories is something subject to change from culture to culture. In other words, genetic differences do not make race a "biological reality".
  - wnoise 10y ago
    They're not visible at the level of looking at one SNP at a time. If you look at a whole lot of genes, you can get a very good idea of race.
  - fvdessen 10y ago
    If you do a clustering analysis on a large sample of DNA data you will get different clusters corresponding to the usual definitions of races or ethnicities, depending on the number of clusters you choose. https://en.wikipedia.org/wiki/Human_genetic_clustering https://en.wikipedia.org/wiki/Human_genetic_clustering
    - openasocket 10y ago
      That wiki page has a pretty substantial "Criticism" section. The Rosenberg et. al. paper even says their paper "should not be taken as evidence of our support of any particular concept of biological race." Their study shows that genetic distance is roughly linear with physical distance, barring obstacles like mountains and oceans. The consensus in the field, based on citations on that wiki page, seems to be that human diversity is a continuum, so any dividing lines you try to make to partition it will be largely arbitrary. It's like looking at a rainbow at trying to divide up the yellow from the orange from the red and so on: you can do that, but your color categories don't completely capture the spectrum visible.
stcredzero 10y ago
Looks like the TL;DR conclusion is that "race" is not just a social construct, but actually has genetic markers which are expressed beyond ethnic heritage. That's not how I read it. My takeaway was that "race" is a social construct that can leave epigenetic markers. In other words, culture can affect physiology. In other words harder sciences are proving that social sciences obsession with identity politics has hindered medical advancements once again. I would agree that many in the social sciences create epistemological problems for ideological reasons.
alistproducer2 10y ago
It's pretty clear you skimmed the article and read from it what you wanted, instead of what it actually said. I read through the responses and you've been pretty thoroughly proven wrong so I won't reiterate the points. Constructively, try not to see news as a chance to reinforce your existing views. Try and do the opposite. try to expand your world view.

deleted 10y ago

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EekSnakePond 10y ago

ITT: San Francisco violently denies the importance of race for bone marrow transplants.

tiatia 10y ago

"conclusion is that "race" is not just a social construct" I mean, come on. This is news? What was he thinking were the different crime rates come from?

sctb 10y ago
This is not a great comment for HN because it's no-information flamebait. Those kinds of posts are off-topic here. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

lngnmn 10y ago

Cultural changes rate are too infinitesimal compared to the time which is required for any genetic change to get a chance to form and propagate through a population to attain a stable presence (forming a distinct trait). The probability that a certain cultural difference induced mutation could be formed (given that there is no flow of information from a phenotype back to genotype) is something incalculable. What might work for a bacteria does not work for humans due to, you see, fundamental differences in the reproductive system and development. There are a few main principles from genetics 101 to consider before making any attempts of "doing science". 1. all mutations are *random* 2. there is no backward flow of information 3. environment does not alter DNA. random mutations do 4. propagating of a mutation is an extremely rare event 5. it takes *many* generations. To understand these principles think why we do not have much mutations of, say, hemoglobin or glucose pathway enzimes. There is another fundamental principle: way to many hipsters in what they call "modern science".

danharaj 10y ago
The article talks about gene expression, which is much more fluid. Another factor that influences gene expression whose effects are just starting to be measured is poverty.
- lngnmn 10y ago
  Gene expression has nothing to do with altering DNA, leave alone any propagation of such "changes".
  - danharaj 10y ago
    > The study examined DNA methylation—an “annotation” of DNA that alters gene expression without changing the genomic sequence itself—in a group of diverse Latino children. Methylation is one type of “epigenetic mark” that previous research has shown can be either inherited or altered by life experience. What are you even arguing against?
    - 10y ago

cb18 10y ago

While this article isn't entirely, reality denying non-sense, in fact mostly the opposite. The researchers do themselves and their readers huge a huge disservice with notions like, “These data suggest that the interplay between race and ethnicity as social constructs and genetic ancestry as a biological construct is more complex than we had realized, Putting forth these notions makes study and understanding of genetics far more convoluted and difficult than it needs to be. Race is ancestry, ancestry is race, plain and simple. Race is ancestry, ancestry is relatedness. Ancestry is the factor of relatedness, relatedness is the factor of race. For example an Englishman has a relatedness factor to a Dane that is hundreds of times greater than than the relatedness factor the Englishman has to a Nigerian. An Englishman and a Dane are of the European race, a Nigerian is of the (sub-Saharan) African race. You'd think this would be the simplest thing in the world to understand, but something about the modern world has caused otherwise for some people. Races are simply large extended families that came about due to imposing natural barriers in the ancient world, deserts, oceans, mountain ranges. "Social constructs" are claptrap that came about from nihilist "post-modernists," and "critical theory" lunatics and agitators seeking to attack and disrupt western society.

danharaj 10y ago
The construction of whiteness as an ideology of European imperial powers is well documented and well studied. I doubt you've ever read any scholarship on the matter.
- dqv 10y ago
  Okay. I mean... You're the one saying it's well documented and well studied. Are you going to prove your assertion?
  - danharaj 10y ago
    If someone were on Hacker News trying to insist that they had violated the laws of thermodynamics or invented a perpetual motion machine, I would not be called upon to prove those laws. Race is a crank theory. It is a most pernicious crank theory because it is tied with some of the greatest brutality the world has ever seen. You have the Internet. Go use it. It is preposterous to give racists the benefit of the doubt and put the burden on us to bring up the same arguments over and over again to refute them.

known 10y ago

"Diversity society will fail" --Putnam; http://www.boston.com/news/globe/ideas/articles/2007/08/05/the_downside_of_diversity/ http://www.boston.com/news/globe/ideas/articles/2007/08/05/t...

sctb 10y ago
We asked you to please stop in response to this exact comment just over a month ago. Drive-by posts like this are not what Hacker News is for. We have to ban accounts that refuse to comment civilly and substantively.

kingkawn 10y ago

if culture impacts DNA then the concept of DNA being subject to mutation as the primary driving factor is at last beginning to crumble. Also if culture impacts genetics then the idea there are races is clearly not the case, but rather loosely organized behavioral groups that can change in whatever direction their common culture takes them next. All of the conclusions being drawn about the implications of this for your hobby-grudges about politics are beyond inane

pc2g4d 10y ago

In my understanding, the article was saying that who your ancestors are has less of an impact on DNA methylation (epigenetic markers) than where you grew up. It's not about race, it's about ethnicity---the cultural identity of the individuals, the environment they lived in. It's not about DNA, it's about how DNA is actually manifested, as represented by methylation markers.

fvdessen 10y ago
The articles states that at least 76% of the observed differences in the population come from their raw DNA. Epigenetics may thus affect up to 24% of the observed differences. So DNA is still the predominant factor.
- medymed 10y ago
  Don't think so, they didn't look at raw dna sequences. They appear to just look at ethnicities, within which there is a lot of genetic variation.

toufka 10y ago

I'll quote myself from a previous comment regarding epigenetics. Epigenetics. It's the make-file for your genetic source code. Certain conditions can cause certain parts of your genetic code to be uncommented or commented-out. There are actually a number of different kinds of comments (histone modifications [1]) - each set of marks particular to a different compiler, in different contexts. And these comments/marks are copied with some fidelity to daughter-cells/children along with a high-fidelty copy of the underlying genetic code itself. So the genes themselves are not being heritably altered, rather the recipe for which gene is where, when can be subtly changed. But again, the same mechanisms that permit the change in expression of those genes during a lifetime can be subsequently changed in the next just as easily. In this way you can store the code for some trait or capability over many generations without having it always be running. It can manifest itself in individual organisms as having very different phenotypes even with the same underlying code. [1] https://en.wikipedia.org/wiki/Histone_code https://en.wikipedia.org/wiki/Histone_code

marxidad 10y ago
What muscles do you have to flex that will eventually lead to methylation of histones?
- toufka 10y ago
  LOTS of things affect epigenetics. It currently appears to be a messy, relatively non-deterministic process with lots of different pathways crossing wires with lots of other different pathways. A snapshot of my mental model of epigenetics (warning: epigenetics/histone modifications are not my particular field of study): "The methylator slides along DNA to methylate histone tails at location 32 of histone 2 while in simultaneous competition the demethylator demethylates methyl groups of histone 1 at locations 4, 12 and 18 under most conditions, or location 32 of histone 2 IFF it is within three histones of an acetylated histone which itself has its acetylation competing with a deacetylator - constantly. And if a certain set of marks occur appropriately in combination, a set of neighboring histones wrap up and hide themselves and their DNA - preventing its hidden DNA from being used in that cell until some other mechanism can unwrap that section. Oh, and (most of) those marks are copied to children/daughter cells right along with the copying of DNA." Because it's so fickle, non-deterministic, and tangled (unlike it's DNA counterpart) it's actually pretty hard to study and is currently (like this afternoon, down your street) a topic of a significant amount of cutting edge research. As the wikipedia article above shows, the 'Histone Code' is still a work in progress, and it now appears unlikely that there is a 1:1 relationship between this chemical mark and that effect, very much unlike the very nice deterministic relationship we found between DNA->RNA->Protein. One common change I've read about that bubbles up to normal life is the capability of nicotine to affect histone acetylation. It seems to rapidly alter histone modifications so as to make other habits/actions more addictive [1] (precisely in a way that we now know THC does not - the original 'gateway drug' mis-extrapolation). [1] https://www.nih.gov/news-events/nih-research-matters/why-nicotine-gateway-drug https://www.nih.gov/news-events/nih-research-matters/why-nic...

mcjon77 10y ago

One thing that I don't hear talked about in many of these discussions about the genetic components of race is how the mixed racial ancestry of many "black" people in Europe and the Americas impacts these studies. MANY blacks in the Americas and Europe have significant European DNA. For example, even though my family identifies as black, my mother and her siblings are almost 50℅ European according to DNA tests. How does this factor in when making medical decisions based on assumptions regarding race?

LordKano 10y ago
As I remember it, something like 80% of people who we identify as African Americans(or black) have significant amounts of European ancestry. Outside of Africa, that's probably to be expected. I too am "black", with two "black" parents but my mother had red hair and green eyes. My son has blonde hair and blue eyes.
macawfish 10y ago
Unfortunately, western medical practitioners and researchers often aren't aware of the complexities of race and racial identity. I spoke with my cousin recently (who is almost done with his pharmacy PhD) and was flabbergasted at how ignorant he was about race as a social, cultural and spiritual phenomenon. Yet he casually spoke of race as a simple demographic category with genetic basis. He'd never heard of "epigenetics", though when I explained it to him, he admitted that it was a plausible idea. Racial identity translates very poorly into actual population genetics, let alone epigenetics.

kenjackson 10y ago

"Scientists and clinicians have increasingly tried to move away from simplistic racial and ethnic categories in disease research, the authors say, and – with the rise of precision medicine – in clinical diagnosis and treatment as well. Studies by the Burchard group and others have found that using genetic ancestry rather than ethnic self-identification significantly improves diagnostic accuracy for certain diseases. But the new data showing that a large fraction of epigenetic signatures of ethnicity reflect something other than ancestry suggests that abandoning the idea of race and ethnicity altogether could sacrifice a lot of valuable information about the drivers of differences in health and disease between different communities." The study shows that abandoning the idea of ethnicity could sacrifice information, but it still seems to indicate that genetic ancestry is more useful than race. Why does the article seem to conflate the two?

nickeleres 10y ago

Ugh, the alt-right supremacists are going to have a field day with mis-information around this o_o

macawfish 10y ago

You know what's crazy? My cousin is months away from finishing his PhD in pharmacy. Over thanksgiving break, he revealed to me that he had never heard the term "epigenetics". I explained it to him. He works for a drug company modeling interactions for new animal antibiotics and he'd never heard the term "epigenetics" My cousin is a bright, driven guy. There are reasons I distrust the western medical establishment.

JamesBarney 10y ago
The other way to look at it is epigenetics is much more important to pop-science than real science.