Lamarck was right!

Or, at least, not so wrong.* It seems offspring can indeed inherit acquired traits: for instance, male mice were taught to associate the smell of orange blossoms with an electric shock. Their sperm was then used to fertilize in vitro, and it was found that even their grandchildren were startled upon smelling orange blossoms. And there are many, many other cases were it has been shown that this type of inheritance is real.

Which is why I get a kick out of people who learned their biology decades ago, and sternly lecture people on the Internet as to how acquired traits cannot be inherited.

* There is some debate about whether this sort of inheritance is really "Lamarckian."


  1. This is not really Lamarckian inheritance.
    The example you cite is the usual thing with epigenetic effects, methylation. It's an interesting effect but there are a few points to remember.

    1. The effect "wears off" in a generation or two and so cannot cause adapatation.
    2. The ability to be methylated is coded for in the DNA sequence. So this is no violation of the central dogma.
    3. It is best seen as an "extended phenotype" effect really. One geneticist used the phrase "blurring a phenotype across generations" which puts the point well.

    Interesting but not Lamarckian.

    1. Neither of us being biologists, shouldn't we leave this debate to the biologists? Some of them apparently think it is Lamarckian and some don't, as my post acknowledged.