Molecular Genetics & The RNA World: topic
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Epigenetics: Was Lamark partly right?
Adam Hall
Monday, 04 February 2008 20:33 UTC
Recent research has implied that the environment can have an effect on shaping the epigenome. This in turn will affect the way our genes are expressed. If this epigenetic change occurs in the germ line, the environmental effect will be inherited. (Erasure is a process which usually wipes out imprinting on genes, which would normally prevent this inheritance, but erasure is not universal amongst all species). Does this imply that Lamarck’s theory of inheritance of acquired characters does partially contribute to evolution along with Darwin’s theory of Natural Selection?
References: Bird, A. (2007). Perceptions of epigenetics. Nature 447: 396-398.
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Replies
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If that was true, then all of the acquired characteristics as a rule must be passed on ( that which is epigenetically associated or not). While it might be quite relevant to say that the acquired epigenetic modifications can be inherited, not all acquired phenotypic changes are hertiable which was the basis of lamarck s theory. Wasnt it? As for darwinian selecting acting at the molecular level, that is definitely in syn with epigenetic selection of modifications for adaptive features.
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Yes Nisha, I agree with you that not all acquired phenotypic changes are heritable. However, as the new research shows that parts of the epigenome may be altered by the environment, (and in some cases this change inherited), does this not resemble a modified version of Lamarck’s theory of evolution? Can we now say that evolution is 99% down to Darwin’s Natural Selection, but 1% due to Lamarckian-like epigenetic modifications that are picked up during an organism’s life time?
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It would be quite relevant to say that, and in fact, the percentages may be more than that! Again, if one were to theortically profile all the acquired epigenetic modifications and then track what percentage of it are more strongly hertiable than others, it would agian suggest a significant bias of genetic domains in ‘inhertiance vs. acquirable characteristics’.
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