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Biotech Science

Your Environment May Change Your Genes 65

An anonymous reader writes "Recent experiments indicate that your environment alters your genes. The longer identical twins live apart, the more their "epigenomes" (genetic sequences that activate or suppress other genes) differ. This possibility could cause a radical shift in the assumptions of biological inheritance (namely that, with minor exceptions, an individual's genes do not change), and indicates the possibility of return of Larmarckian inheritance which had formerly been consigned to the dustbin of biology."
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Your Environment May Change Your Genes

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  • by FrontalLobe ( 897758 ) on Wednesday July 06, 2005 @02:27PM (#12996194)
    I'll be interested when my environment can change my jeans... I'm lazy...
    • I'll be interested when my environment can change my jeans... I'm lazy.

      Be careful what you ask for. You might wake up and find yourself in a pair of bell-bottoms.

      -
  • I'm wondering if the epigenes that are changed, are passed on to the offspring. The article wasn't really clear on that.

    -- helm
    • by dannyitc ( 892023 ) on Wednesday July 06, 2005 @02:54PM (#12996436)
      I think it would be reasonable to assume the article was referring to DNA in somatic cells, as altered gene expression only has the capacity to change an organism in somatic cells, and thusly, would be the only type that would reasonably respond to envionmental pressures. My (somewhat educated) guess is that the gametes would remain untouched.

      This really shouldn't come as a big surprise. Differential gene expression is one of the major unexplored areas of genomics, and we're just beginning to scratch the surface of how organisms as complex as humans can develop with a number of genes comparable to that of a roundworm. Changes in the environment controlling gene expression is something that's well documented in many different organisms.

    • For the most part, no. As the article mentions, the events right after fertilization strip off most methylation of genes and then add them back on- basically, assuming the methylation machinery works right, you start with an epigenetic blank slate- which is nice, because otherwise you'd start life with the methylation patterns of an x-year old- however old your parents and their germ cells were at your conception.

      It's important to note that one of the critical functions of DNA methylation is to control e

      • In mice, recent discoveries indicate that methylation of embryonic epigenomes can be controlled by diet [cornell.edu]. Feeding pregnant mice one, rather than another, diet caused offspring to be yellow, or not, as determined by methylation. In rats, methylation was partly "blank" at birth, and "set" by a parent's incessant licking the newborn. Even if the parent was adoptive, they reproduced their methylation in the adopted offspring.

        So even in relatively closely related species, there are big differences in epigenetic
    • There is some evidence of epigenetic changes being passed on to offspring in other systems.
      This article from nature talks about some work from Emma Whitlaws group that sees heritable variation in coat colour of mice that are genetically identical. http://www.nature.com/ng/journal/v23/n3/full/ng119 9_314.html [nature.com] Subscription required
      http://www.mmb.usyd.edu.au/research.php?person=whi telae [usyd.edu.au] Lab Webpage

      Heritable epigenetic variation is however not Lamarkian, it is Darwinian inheriance. You still need to ha

    • Probably not exactly by this mechanism, but undoubtedly, there is a means of passing adjustments to environment on to our children. You don't need "science" to see that physical differentiation amongst peoples, differences that had extremely low occurrences before the differentiation, happens to quickly to be due to Darwinian selection. There has to be either a mechanism by which the parent's physical adjustments to extremes in their environment is being passed on or one by which adjustments that the pare

  • by Wandering Hoosier ( 621835 ) on Wednesday July 06, 2005 @02:34PM (#12996267)
    You've misrepresenting what the article says: Environment alters gene EXPRESSION, not genes. That makes the whole "Lamarckian" inheritance comment irrelevant, too.
    • by exp(pi*sqrt(163)) ( 613870 ) on Wednesday July 06, 2005 @02:46PM (#12996369) Journal
      Not completely irrelevant. Organisms may inherit features of the current state of gene expression from their parents. So even though the genome is unaltered by the environment, some inherited extra-genetic information is modified by the environment.
      • Interesting. A bit like passing on the executable binary intact, but also inheriting the most current config file. What is the extra-genetic information, and what is the process of inheritence?
        • I can't find an article about it online. I read about it in a book a few years ago. Basically there is a frog or lizard that exists in two slightly different forms depending on whether its environment is wet or dry. This state is inherited from the parents but not as part of the genome. It may be something as similar as hormones that are supplied by the parent during development or something like gene inhibitors or promoters attached to the DNA. I'm not sure the mechanism was understood at the time I read a
        • The ways in which genes are expressed are often determined by other protein and enzymatic structures in the cell. It's more like passing a byte-code file intact, and running it on copies of the same interpreter.
          Really, you can't stuff rabbit DNA into a dog and get a dog. Not gonna happen. It takes a dog to make a dog, barring extreme measures, and even then it takes a very specific kind of dog to make a similar specific kind of dog -- and even that often doesn't work.

          Watch out for the creeping delusion
    • by Otter ( 3800 ) on Wednesday July 06, 2005 @03:00PM (#12996506) Journal
      A few points:

      1) The issue here is methylation and demethylation of DNA sequences, not the submitter's "genetic sequences that activate or suppress other genes".

      2) Methylation patterns are heritable through mitosis, so he's not necessarily wrong to say that genes are being "changed".

      3) I forget the details of methylation in embryos, but most of it is wiped out between generations. In any case, sperm and egg cells are segregated very early on, so the environment should have minimal effect on changes that get passed along to offspring. The article doesn't address the issue at all.

      I applaud the submitter's enthusiasm, as well as his not putting in the usual stupid, inflammatory question at the end. ("Could epigenetics mean the end of Microsoft?") But he could have cut back on the speculation a bit...
      • Headline: Slashdot now banned in Kansas [cnn.com] and Serbia [msn.com]!
        Probably in a few other places too.
      • I applaud the submitter's enthusiasm, as well as his not putting in the usual stupid, inflammatory question at the end. ("Could epigenetics mean the end of Microsoft?")

        In fact, he comes off even better now that we've gotten "Could this be the start of a Pleistocene park?" a few stories later...

    • I would call Lamarckian a useful shorthand for a class of largely ignored phenomena. For instance, there is a Russian plant, maybe a flax, that if you grow it in poor soil, it has one morphology, and you grow it in good soil, it has another morphology. Except if you grow it in poor soil and plant the seeds in good soil, the children plants has the morphology associated with the poor soil. Kind of cute. This sort of unreasonable result is where good scientific advances come from. And since it is so unre
  • by Doug Dante ( 22218 ) on Wednesday July 06, 2005 @02:42PM (#12996340)
    Matt Ridley [pbs.org]'s book Nature via Nurture [amazon.com] gives many examples where environment and genes affect one another:

    For more than 50 years sane voices have called for an end to the debate. Nature versus nurture has been declared everything from dead and finished to futile and wrong - a false dichotomy. Everybody with an ounce of common sense knows that human beings are a product of a transaction between the two.

    • Testify. I hate nothing more (well, maybe a few things more) than this God Damned John Locke 'Tabula Rasa' crap that's so prevalent these days.

      If we were all blank slates when we were born then there should be Human Cultures without Love, without War, without Senses of Humor, etc.

      You are a unique amalgam of your genes expressing in response to your enviroment. For example, if I have gene groups that code for huge frickin' wisdom teeth, and person B has gene groups that code for normal sized wisdom teeth

  • by Apreche ( 239272 ) on Wednesday July 06, 2005 @02:43PM (#12996345) Homepage Journal
    If your environment is a radioactive waste dump you can be damn sure it will change your DNA.
  • Has always been the "random but useful" nature it relied on. Maybe it is just a matter of getting my head around the huge numbers involved in the statistical chances of enough random mutations piling up on each other to give an organism stereoscopic color vision. If this discovery turns out to support even a rudimentary "talk back" mechanism that allows the environment to have some say on the number and nature of mutations I think it goes a VERY long way it making Evolutionary Theory a much more elegant ide
    • The environment does have a talk-back mechanism on the nature of mutations. It's called natural selection. Organisms with mutations that make them more fit for their environment will be selected for and the genetic makeup of that population will change.
      • Yes, that's exactly what I was thinking when I read that post. I think the "problem" here is that the GP doesn't even understand the very basics of evolution.
    • Evolution Theory already has a talkback mechanism. Its called "natural selection". It provides a powerful feedback mechanism that filters out the non-beneficial genetic variations in a population. The repair and maintainance of the DNA is part of the phenotype and is also subject to evolutionary pressures of course.
    • by orasio ( 188021 ) on Wednesday July 06, 2005 @03:02PM (#12996526) Homepage
      You just need to learn more statistics.
      Just imagine.
      10 out of 100000 organisms get a light sensor.
      They are better, so they become dominant.
      Of the mutant offspring, lots do have a tendency to develop more than one light sensor.
      More light sensors are better than one.
      Now you have a fly-like eye.
      Focusing lenses are easy.
      The sensor must be protected by something, because it doesn't work otherwise, and the clearer the better, and those who have better focusing clear flesh covers for their eyes, can sense better their environment, and find better partners.
      What you view as a huge advantage, can be broken into lots of incremental advantages that are easily explained by evolution.
      Of course, it's almost magical that evolution can happen just by birth and death.
      You never stop to think that all the tasks a modern computer can perform are just the result of the arrangement of "nand" gates, but there's no magic, and we understand it, because it's simple enough to be understood.
      For evolution, it has the advantage of thousands of millions of years of incremental design.
      • I "understand" the statistical models, but once you go from 10 in 100000 to 1 in 40,000,000,000 over a time period of 78,000,000 years, concurrent with a hundreds or thousands of other useful features (teeth, claws, scales, a sense of smell, orgasm, varios appendages, flame-throwing ducts, etc.) it all gets a bit more complex. When you add in the stastics for all of the parts as a whole you are talking about STAGGERING numbers.

        And for all the "natural selection" comments thanks for pointing out the obvious
        • 1 in 40,000,000,000 is all that is needed, since that special 1 is who will survive and replace the other 40,000,000,000. Useful features develop in paralel, and there weren't many before sexual reproduction (the history of life is mainly that of single cell bacteria for a long, long time).

          Also natural selection does not explain evolution. Natural selection + variation does. Natural selection can't change a species if all the individual to select from are identical.

          The fossil record has plenty of holes in
        • If you are talking about a timescale that includes millions of generations (think how fast insect generations can change, within a few days for some of them) and population counts in uncountable billions (again, think about insects) then yes, a 1 in 1,000,000,000 mutation that grants a 0.01% larger chance to reproduce - such a mutation will get 'accepted' by 99% of the population within a few hundred years - an insignificantly small time, compared to the timescale of the evolution.

          Do some simulations to t
        • There's another far more powerful effect going on in evolution that people rarely hear about in the common explanations of evolution. The common explanation of evolution is as a sequence of individual beneficial mutations, like climbing a ladder. If that's how it worked then critics would be right, evolution would not have been able to produce the incredible variation and complexity we see today. That kind of advancement is about the least powerful mechanism in evolution.

          In fact I'll even assume that every
      • Then why do we not have three eyes ?
        Two in front and one (atleast a rudimentary one) on the back.
        This would have saved many a deer from being ambushed from behind ...

        Also to have a very rudimentary eye behind the head doesnt look like it consumens too much energy for it to be a huge disadvantage during droughts
        kR/\/
      • It's even better than that really because a light sensor is pretty complicated. But the structures in a light sensor can be useful in many other areas. So they can evolve independently without the light sensor coming to spontaneously exist. Then one day these components evolve to come together and wammo...you have a light sensor. This is one of the main places that Intelligent Design people get it wrong. They say the eye is too complex to have evolved from randomness...but that is predicated on the belief t
    • 4 billion years, 148,847,000 km of surface area, an astronomical amount of life per m, let that be a start to comprehension.

      And don't forget that the genetic code is quite modular, so a single mutation could give you an extra arm, without the need to "re-evolute" the thing. Just to give a silly example. A better , real-life example is an extra nipple, some people have them.

      Coincidentally, our fellow mammal species have a large variation in the number of nipples, so maybe it's not so strange that an extr
      • It should be km^2 and m^2, I used the special square char but /. stripped it out..

        No need to panic, you can safely continue your life.
      • In the nipple vs eye debate, the main reason why ectopic nipples are much more common than eyes is the much complex nature of eye development. Having studied eye development a bit in a developmental biology course, there's a huge number of issues regarding tissue competancy, signalling, precursor tissue placement, and gradients of various signalling molecules that have to align perfectly just for an ectopic eye to form. Not to mention the nightmare of trying to guide an optic nerve with developmental cues
    • "I think some people have fewer "religious" objections to evolution and more "it just doesn't seem possible" ones than most scientists would like to admit."

      First, neither religiously motived reasons nor arguments from personal incredulity are valid arguments for the rejection of sound science. Second, spend some time online reading what people who reject evolutionary biology write. It's been a hobby of mine for quite a few years now, and in my experience the overwhelming majority reject evolution becaus
      • I didn't say they were valid arguments. When I said "my problem", I fully acknowledged it was MY problem with evolution, not a grand theory refuting it. I think that many scientists would prefer to think that the reason some people don't accept evolution is religion. I have read what people have written about elvolution though clearly not as much as you. While agree that the majority do harp on the creationist view, I think there are some who have some concerns about the theory itself. How valid those conc
        • The way I deal with it, is to believe there is infinite amount of time in universe and multi-verse (ie there is a probability that other universes will exist even though this one may end through Heat Death or the Big Crunch).

          Therefore, there is infinite time for anything to happen. You exist don't you? Or at least think you are self aware? Now what is the probability of that happening? Very very extremely low... Not only did you not have to not die today, but you had to survive up until this point and befo
    • I think you're right. Many people may be reluctant to challenge evolutionary ideas for fear of being labeled a religious fanatic or otherwise ridiculed.

      While I believe that evolution is the best explanation given on the origin of species. I think there are major problems in the way that it is presented, if not the theory itself.

      For example, people often say that animal's feature x was designed for such-and-such. Well, no it wasn't, if it was evolved.

      Or people will say that thus and such happened, so a
    • If life is too complex to have developed on its own, where the hell did the all-powerfull and totaly incomprehensible being come from that created it all with a snap of his finger?
  • I saw that as (Score:1, Offtopic)

    by FLAGGR ( 800770 )
    Your enviroment may change your jeans.
  • I'd hate to be a biologist just now finding out Lysenko might have been on to something.
  • Field day (Score:1, Flamebait)

    by centauri ( 217890 )
    Man, are the Creationists going to have a field day with this, whether or not they've take the time to try to understand it.
    • Its odd the NYT article doesn't mention Lysenko [wikipedia.org] whose promotion in stalinist russia [ok, here it comes: in soviet russia the traits determine your genes. satisfied?] was, amongst other things, a refutation of darwinian evolution, which did not fit comfortably in to Salin's idea of how the state should be able to make a new, improved kind of human being.
      I think the lesson is that
      1. you don't want to get on the wrong side of a government that has its own ideas about biology (are you listenin' Dubya?) and
      2. AN
  • It seems to me that what the article is talking about is expression of genes in normal cells. (Note, I didn't read the article because of the whole subscription thing, although I have heard some discussion of this.) Personally, I was always taught that an individual's genes could change via mutation. Mutations in the genes that regulate cell cycles, for example, can cause cancer.

    Inheritance is a separate issue, though. The genes for your children are controlled by the genes in eggs or sperm. These are
  • If there's a lot of dirt or grime around and I get dirty I have to change my jeans. You can't expect the environment to just stay off of them, after all - especially if you have to kneel down in it.

    Oh.. wait..
  • by Neeze ( 883091 )
    I guess I should start spending more time at fashion shows...
  • by TheUnknownCoder ( 895032 ) on Wednesday July 06, 2005 @04:42PM (#12997530)
    Genes altered by the environment:

    Gene Hackman [imdb.com]: Jailed as a teen in 1946 for stealing candy & soda pop from a convenience store now lives a wealthy life in New Mexico.
    What's causing the mutation: With more than 70 movies to date, strong light sources constantly shining on his forehead can be traced as the culprit.

    Demitria Gene [imdb.com], a.k.a. Demi Moore: From spending her minimum-wage hard-earned money with coke to earning $12,500,000 per movie and dating a kid who could be her grandson.
    What's causing the mutation: Not really sure... Could be frequent exposures of her bare body to the cameras or the many plastic surgeries she had done.

  • The genome (the actual sequence of A, T, G, and C that make up the genes) is still still the same (for the most part, see below). The notion that changes in chromatin structure (the way that DNA is wound up in higher order structures) or that MODIFICATIONS of the ATGC's take place (the fundamental base sequence is still the same) is not surprising, nor is it new. And, of course, these changes may have an effect on how the genes are read out (i.e. the resulting phenotype/appearance of the organism is going
  • More and more we're finding out that evolution is driven by Darwinian and Lamarckian influences.
    If he hadn't faked the frog experiments, his theories might have been studied more. There are examples of Bacteria exchanging DNA in response to environmental factors. If your mother was a crackhead, guess what, you're born addicted to crack. There are drugs that affect you if your *grandmother* took them.

    - Mike

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