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Epigenetic Inheritance: Can Evolution Adapt?

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Given how routinely evolution fails to explain biology, it is remarkable that scientists still believe in the nineteenth century idea. One of the many problems areas is adaptation. Evolution holds that populations adapt to environmental pressures via the natural selection of blind variations. If more fur is needed, and some individuals accidentally are endowed with mutations that confer a thicker coat of fur, then those individuals will have greater survival and reproduction rates. The thicker fur mutation will then become common in the population.

This is the evolutionary notion of change. It is not what we find in biology. Under the hood, biology reveals far more complex and intelligent mechanisms for change, collectively referred to as epigenetic inheritance. You can read more about the challenge that this form of inheritance poses for evolution here. The take home message is that adaptation is routinely found to be not blind, but rather responsive to environmental pressures. The fur becomes thicker not by accident, but via cellular mechanisms responding to a need.

There is still much to learn about this phenomenal built-in adaptation capability, but it now is clear, and has been for many years, that epigenetic inheritance is a dramatic departure from evolutionary expectations. Indeed, this sort of adaptation is closer to the ideas of the long disgraced French naturalist Jean-Baptiste Lamarck (1744-1829). Lamarck’s idea was that offspring inherit traits or characteristics that were acquired by the parents. Although epigenetic inheritance is far more complex than anything Lamarck imagined, he was remarkably close to what is now being discovered. You can see a recent review of what has been learned here. Only a few years ago positive references to Lamarck drew heated response. Such ideas were not tolerated. Now his name appears regularly in the epigenetics literature.

This leaves evolutionists in an awkward position, to say the least.

Continue reading here.

Comments
The reasoning is that withOUT the behavioral change the organism would normally die. But, of course, this behavioral change (which is heritable) is also selectable.Winston Macchi
June 10, 2009
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BTW epigenetics is good confirmation of Dr Spetner's "built-in responses to environmental cues"- which is part of his non-random evolutionary hypothesis- see "Not By Chance"...Joseph
June 10, 2009
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Of course the theory of evolution is OK with epigenetics. It's OK with every form of change. It's like the blob- it just keeps consuming everything in its path. Can evolutionists explain it? No, but they will incorporate it. Very different cells and organisms with the SAME DNA? Oh yeah natural selection, no problem.Joseph
June 10, 2009
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iconofid, yep, and blending inheritance (~incomplete dominance) is in the mix, too. pun intended.Khan
June 10, 2009
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Khan say: so do you think that epigenetic inheritance falsifies Mendelian inheritance? i see no problem with both co-existing. Indeed. And how on earth could any mechanism or process of change be a problem for "evolution"? I could understand if the claim was that such things were a problem for stasis.iconofid
June 10, 2009
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Cornelius,
Good point! I was thinking of the blending idea of heredity. As
I'm glad you agree with me. Now, are you going to fix your website? bc it explicitly states there that Darwin rejected Lamarckism. http://www.darwinspredictions.com/#_5.2_Biological_variation
The predictions that epigenetic inheritance falsify are not minor problems that are reasonably explained under evolution.
so do you think that epigenetic inheritance falsifies Mendelian inheritance? i see no problem with both co-existing.Khan
June 10, 2009
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PFan, Dr. Hunter: Hiram Caton's "Getting Our History Right: Six Errors about Darwin and His Influence" paper says:
The Exhibition also ignores the Pangenesis theory and its influence on Darwin’s shift to substantial Lamarckian explanation in the 5th and 6th editions of Origin. Indeed, it implicitly denies Darwin’s Lamarckism by baldly stating that “Charles Darwin offered the world a single, simple scientific explanation for the diversity of life on Earth: evolution by natural selection [bold face in original].
and later
In the 5th edition of Origin [...] [he] also ascribed a greater weight to Lamarckian inheritance (“use and disuse”) than he had in previous editions.
(Caton also claims that some famous early supporters of Darwin including Haeckel and Thomas Huxley were even further from full orthodoxy on natural selection than Darwin himself was.) T. Ryan Gregory's post "Lamarck didn't say it, Darwin did." offers a similar argument with some relevant Origin quotations. My eye also happened to fall on this quotation http://darwin-online.org.uk/content/frameset?viewtype=side&itemID=F373&pageseq=155 from the first edition Origin
The eyes of moles and of some burrowing rodents are rudimentary in size, and in some cases are quite covered up by skin and fur. This state of the eyes is probably due to gradual reduction from disuse, but aided perhaps by natural selection.
which in context (p. 137, Ch. 5 on "Use and Disuse") appears to acknowledge the reality of inherited loss from disuse as an evolutionary mechanism, distinct from natural selection.anonym
June 10, 2009
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Arthur Hunt, ------"(As indicated in the preceding, Darwin had no way of knowing about genetic vs epigenetic mechanisms.)" Didn't he postulate gemmules instead? Little grains that are secreted by the body's organs and collected in the male's reproductive organ?Clive Hayden
June 10, 2009
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"The take home message is that adaptation is routinely found to be not blind, but rather responsive to environmental pressures. The fur becomes thicker not by accident, but via cellular mechanisms responding to a need."
Um, epigenetic changes are every bit as random and haphazard, when it comes to the specific genetic targets of such changes, as so-called genetic changes. If one is going to argue that epigenetic changes are contrary to evolutionary mechanisms, one needs to bring to the table evidence that shows that a particular epigenetic change was aimed at one and only one target, and not to an array of loci, one or more of which happened to provide some advantage. Absent such evidence, then we're still talking about Darwinism - natural selection acting on random variation. (As indicated in the preceding, Darwin had no way of knowing about genetic vs epigenetic mechanisms.)Arthur Hunt
June 10, 2009
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Khan: Good point! I was thinking of the blending idea of heredity. As for your question:
So, taking what you’ve written about epigenetics at face value, it seems that these new discoveries only show that Darwin’s ideas about inheritance weren’t as off-base as we thought. so how does this pose a problem for evolution?
It is a problem for evolution because Darwin's ideas have long since been dropped with the integration of Mendelian genetics. The predictions that epigenetic inheritance falsify are not minor problems that are reasonably explained under evolution. For instance, one can't merely resurrect pangenesis, or some such, to explain what we now know.Cornelius Hunter
June 10, 2009
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Nakashima-san, Please read Equivocation and EvolutionJoseph
June 10, 2009
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Passing on information through teaching and/or communication is a good way to get around deficiencies caused through bad mutations. If one has the ability to teach and learn, then one can avoid many natural problems of bone and flesh.90DegreeAngel
June 10, 2009
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PFan, I did. Charles Darwin's book the variation of plants and animals under domestication. or if you're pressed for time just google "pangenesis" and you'll find multiple sources.Khan
June 10, 2009
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Khan, Please cite a source for us to check.PhilosophyFan
June 10, 2009
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Cornelius, It's actually very easy to defend that statement. Darwin postulated a theory called pangenesis, in which gemmules from somatic cells, responding to use and disuse, would be spread throughout the body, sometimes accumulating in germline cells. in this way, acquired characteristics (for example, giraffes reaching for higher leaves) could be passed on. He argues this in "the variation of plants and animals under domestication." so what you are describing here matches Darwin's predictions.Khan
June 10, 2009
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Khan: I agree with you that Darwin was a bit vague on a mechanism for heritable variation. But you'll have a difficult time defending this:
what little he does propose is close to Lamarck’s idea of inheritance of acquired characteristics.
Although Darwin was a bit vague, what is important is that his idea required blind variation, versus Lamarck's responsive variation. Epigenetic inheritance falsifies evolution's prediction about adaptation and evolutionists are in denial about both the evidence, and its implications. They deny the evidence, and then when that is no longer possible, they say it doesn't matter. (Then why did they deny the evidence?) You can read more about it here: http://www.darwinspredictions.com/#_5.2_Biological_variationCornelius Hunter
June 10, 2009
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Mr Joseph, “Evolution” is NOT being debated. I'm sorry, I get a different perspective from Dr Hunter: You can read more about the challenge that this form of inheritance poses for evolution here. This leaves evolutionists in an awkward position, to say the least. If you think Dr Hunter should choose his words more carefully, I fully support you.Nakashima
June 10, 2009
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Dr. Hunter, As I'm sure you're aware, Darwin was pretty vague on a mechanism for heritable variation in Origin of Species. However, what little he does propose is close to Lamarck's idea of inheritance of acquired characteristics. THis is one of the reasons the book fell out of favor until the genetic revolution provided a clear mechanism. So, taking what you've written about epigenetics at face value, it seems that these new discoveries only show that Darwin's ideas about inheritance weren't as off-base as we thought. so how does this pose a problem for evolution?Khan
June 10, 2009
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Check out this post on Pharyngula from April 2008 about the rapid changes in some lizards on an Adriatic island over 30 years (developed cecal valves, etc.). It is quite comical: http://scienceblogs.com/pharyngula/2008/04/still_just_a_lizard.php Basically, for the first couple hundred comments, the "PZ Patrol" pound their chests about the indisputable confirmation of their theory, mocks any who disagree, etc. They even laugh hysterically at "creationists" remarking that it seems like a Lamarkian-style development rather than a Darwinian one. This continues for a couple days (couple hundred comments), until the hoardes moved on to the next batch of posts. The sensible ones that remained finally said, "okay, let's be honest, there's no way these were novel features developed randomly" (as PZ triumphantly cheered over and over in his initial post). They then decided (because their worldview required them to) that the features developed in a Darwinian fashion thousands or millions of years ago, went dormant, and were somehow re-activated on the new island. Excellent "science"uoflcard
June 10, 2009
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There's a guy who goes by the handle "supersport" who's done a lot of research in epigenetics and lamarckism. One of his hypotheses is that brown bears will turn into polar bears after a few generations in the arctic. I'm a bit skeptical, but it does make you wonder why such an experiment has *never* been performed.herb
June 10, 2009
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Oops- The reasoning is that withOUT the behavioral change the organism would normally die.Joseph
June 10, 2009
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Winston, The reasoning is that with the behavioral change the organism would normally die. The behavioral change allowed the organism to live thereby thwarting NS.Joseph
June 10, 2009
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Evolution is left with the unlikely explanation that evolution constructed elaborate adaptation mechanisms ... This seems likely, even intuitive. Indeed, if evolution is to occur there must to be adaptive mechanisms. If there were none, that would be conclusive evidence against it. Interestingly, epigenetic inheritance now sits along side germline mutation.Winston Macchi
June 10, 2009
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If an organism can alter its behavior to deal with a genetic “disability” then natural selection is thwarted. Why?Winston Macchi
June 10, 2009
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Nakashima, "Evolution" is NOT being debated.Joseph
June 10, 2009
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Dr Hunter, If it is hertiable variation that is being selected, it is still evolution. Darwin himself had some odd ideas in this area. You are pointing out that the principle that all information flows in one direction (from genotype to phenotype) and from one source (the sequence of DNA letters) has exceptions.Nakashima
June 10, 2009
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"Evolution in Four Dimensions" discusses epigenetics. It is very interesting how the SAME genetics can lead to very different forms- just look at our bodies- same DNA yet the cells can look very different from each other and carry out very different tasks. It also discusses behavior- as in behavior can trump genetics. I say BOTH of these are issues for the theory of evolution. If an organism can alter its behavior to deal with a genetic "disability" then natural selection is thwarted.Joseph
June 10, 2009
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Eva Jablonka, coauthor of that paper, also talks about epigenetics in "Evolution in Four Dimensions", which she co-authored and which is advertised on Mike Gene's Telic Thoughts blog. I've read it and it's an interesting book, but it's no threat to Darwin. Darwin didn't say that mutations to DNA were the only factor in evolution, in fact he didn't know what DNA was or how heredity worked. But he did realize that something caused variations in offspring and some of those variations could be inherited. He also realized that sexual selection played a big part in evolution. Epigenetics is just one more factor. Strictly materialistic, no Intelligent Designer here.djmullen
June 10, 2009
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