Nearly two centuries ago, Lamarck
propounded the theory of inheritance of characteristics acquired by parents in
their life time, by progeny. The textbook example of his explanation of
evolution claims that giraffe got its long neck by trying to eat leaves from
tall trees, generation after generation.
But widespread acceptance of ideas from Darwin,
Mendel and the science of molecular biology tolled the death knell of Lamrck's
theory. Now it appears that Lamarck will come back, making a grand entry through
the science of epigenetics.
Epigenetics is usually about how genes
are switched on or off depending on the environment of an organism. Nobody knew
that the genes that are switched on will continue to be switched on in the
progeny also. But new results show that the epigenetic modifications can and do,
pass from one generation to next.
Scientists experimented with mice, giving
them mild shocks along with specific smells till they started associating the
smell with fear of shock. The children and grandchildren of these mice when
exposed to the smell, exhibited fear. Demonstrating that environmental stresses
undergone by parents prepare the unborn children to face the same stresses.
Similar studies in the recent years suggest that biological
evolution and cultural evolution are a continuum. It appears that in this
century, we may see more biologists entering socio-cultural research.
Nature
eurosci. http://dx.doi.org/10.1038/nn.3594(2013)
'Scientists experimented with mice, giving them mild shocks along with specific smells till they started associating the smell with fear of shock. The children and grandchildren of these mice when exposed to the smell, exhibited fear.' Would be useful to have a citation for this. Also has this result been replicated by other studies? thanks!
ReplyDeleteThis was mentioned in a review of a study in a French magazine -it was a Japanese scientist who was doing the study.
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