Political Commentary, Science And Society

Obesity

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Are we entering an epigenetic spiral of it?

The relatively new fields of epigenetics and nutrigenomics are showing that changes in gene expression can be produced by environmental mechanisms. Could rising levels of obesity alter our genes, and, in turn, could these obesity-favoring alterations be passed on to future generations?

OK, I’m a little confused. Isn’t there a difference between the gene expression and the gene itself? Are they really saying that the environment can change the genes in a way that makes the trait acquired as a result of the environment heritable? That is, are they saying that Lamarck may have been onto something?

[Update a few minutes later]

Just a coincidence, I’m sure, but amusing that this story came out two days before Darwin Day.

And of course, Darwin was born on exactly the same day as Abraham Lincoln, in 1809. In fact, in protest of “President’s” Day, which trivializes the memory of both Washington and Lincoln, I think I’ll go put out the flag.

5 thoughts on “Obesity”

  1. I’ve heard of recent work that in addition to DNA, there are tags that influence the expression of genes. Like DNA they can be inherited. But they are more easily changed in reaction to environment. One factor I’ve heard is that a given gene may be tagged differently depending on which parent it came from.

  3. OK, I’m a little confused. Isn’t there a difference between the gene expression and the gene itself? Are they really saying that the environment can change the genes in a way that makes the trait acquired as a result of the environment heritable? That is, are they saying that Lamarck may have been onto something?

    Essentially, yes, he was partly right. Epigenetic changes such as methylation and histone modification can silence certain genes, and are heritable through the process of genomic imprinting. This does not change the actual nucleotide sequence, but does determine how the sequence is initially expressed by the offspring.

    http://en.wikipedia.org/wiki/Epigenetics

    and

    http://en.wikipedia.org/wiki/Genomic_imprinting

    cover this pretty well.

  4. There was fairly recent study comparing babies born in Europe in WW-II to those born before and after the war. They deal differently with food (metabolism, heart disease, etc), and the early conclusion seems to be that a mammal fetus is programmed to anticipate the type of nutritional environment they’ll exist in. In the case of the WW-II babies, they were adapted to an environment of shortage but grew up eating a rich surplus. It seems various sets of genes are turned off and on based on early signals.

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