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Lamarckism is a pre-darwinian theory according to which an organism's traits acquired to adapt to the environment are passed onto its offspring. A couple of years ago, I attended an event with Richard Dawkins and Jerry Coyne, both preeminent evolutionary biologists, in which I remember them agreeing that it is basically B.S. and that acquired traits don't get passed but instead propagate themselves through natural selection. As a non expert in biology, it does not make sense to me that acquired traits would make their way into the genotype and then get passed on, which coincides with what Dawkins was saying. But I am a non expert.

I also have read a few things about epigenetics and it sounds strangely similar to lamarckism. Steven Pinker also discusses all these things in The Blank Slate and he gives a notion that thare is some idealistic ideology behind promoting ideas that we can radically change an organism by environmental conditioning and "save" those changes into the genotype. He says that ideology is to justify government programs aimed at rapidly enhancing mankind whereas natural selection, which proponents of such ideas may deem reactionary, simply is not so optimistic.

My questions are:

  1. Is lamarckism, or inheritance of acquired traits, been conclusively discredited?
  2. What does lamarckism relate to epigenetics
amphibient
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    Can you provide any example suggesting that Larmackian inheritance is not discredited? Also perhaps search here at https://biology.stackexchange.com/search?q=lamarck and see if your question is answered by anything you find there? – Bryan Krause Apr 03 '20 at 06:25
  • I dunno if it has or not, that's why I'm asking – amphibient Apr 03 '20 at 16:24
  • SE Biology is a question and answer site about biological problems that are capable of objective answers. A question on whether a theory has been discredited does not fit this bill. If I say "yes, all of my scientific colleagues agree", then I am only expressing an opinion. A better question is "is there any evidence for Lamark's claim that (e.g.) by stretching its neck a giraffe elongated its neck and this caused a change in the DNA of the gametes that was inherited by the next generation". It is up to the proponents of a theory to provide evidence. There is plenty for Mendelian genetics. – David Apr 03 '20 at 22:24
  • One of the crazy results of the past decade is the demonstration that conditioned fear is inherited by offspring, and even offspring' offspring. Here is a readable dispatch of the original study: Szyf, M. (2014). Lamarck revisited: epigenetic inheritance of ancestral odor fear conditioning. Nature Neuroscience, 17(1), 2. –  Apr 05 '20 at 23:14

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The question is interesting at many levels. Of course, in biology and in any other science there is no absolute or 'objective' truth about some given phenomenon if we really care to look at the nuances. Lamarck seems to be vindicated mainly by a wave of empirical work on patterns of transgenerational inheritance, particularly in the field that is known as epigenetics. You can read a good intro-level review here for some recent developments, some particular examples here, or a more conceptual reading here.

As an evolutionary biologist myself, I will say that most other biologists acknowledge that epigenetics and transgenerational inheritance are important and have solid empirical support, but (for various reasons) some of them are hesitant of calling that 'Lamarckian'.

By the way, Dawkins was a very effective science popularizer, but he does not practice science nowadays, and many of his ideas lie in what is known as 'scientism', which is a blind confidence in science as an absolute truth that is inflexible. The same applies to many positions of Steven Pinker, deGrasse Tyson, etc.

TumbiSapichu
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    Just to add that Lamarck is not given credit for epigenetics because he turned out to be somewhat right but with a wrong reasoning. In science we try to credit people who provide correct theories, anyone can be right randomly sometimes. However Lamarck contribution to the field was to popularize the idea of evolution of species. In facts, that species evolve was accepted by most biologists of the 19th century, and even the population. It became a controversial idea only after Darwin showed that humans are not any more special than macaques, frogs or goats, but just a variation of life. –  Apr 05 '20 at 23:10
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    The comment about Dawkins, Pinker and Tyson is unnecessary. –  Apr 05 '20 at 23:11
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    @baca the comment is relevant because the OP explicitly mentions them. And I'm discussing their ideas (i.e. scientism) because it is important in the context of the question (just as discussing Lamarck's ideas). – TumbiSapichu Apr 06 '20 at 02:45
  • Dawkins is pretty straight forward about absolute truth not existing in science, his positions it is merely the best way of collecting and assessing knowledge we currently have, which most scientists would agree with. – John May 05 '20 at 18:49