A new book has just popped out – The Epigenetics Revolution by Nessa Carey – and accompanying it is the usual epigenetics-related suggestions that Darwin was wrong. Take this from Peter Forbes in the Guardian:
[E]pigenetics finally reaches that “everything you’ve been told is wrong” moment when it claims that some epigenetic changes are so long-lasting they cover several generations: they can be inherited. This flouts one of biology’s most cherished dogmas – taught to all students – namely that changes acquired during life cannot be passed on – the heresy of Lamarckism.
But the evidence that this can occur in some cases appears to be growing. There are lab experiments with mice and rats in which epigenetic effects on coat colour and obesity can be inherited. More suggestive evidence comes from a vast, unwitting and cruel experiment played out in the second world war. In 1944, during the last months of the war, a Nazi blockade followed by an exceedingly harsh winter led to mass starvation in Holland. This had a huge effect on babies born at the time, and the effects of poor nutrition on the foetus seem to have persisted through subsequent generations.
Thankfully a few people such as Jerry Coyne are placing this noise in context:
I haven’t read the book, and although it might make Darwin swoon if the old git were to be resurrected, the discoveries of genetics and the mechanism of inheritance itself would make him swoon far more readily. And I know scientific revolutions; scientific revolutions are friends of mine; and believe me, epigenetics is no scientific revolution.
So, Mr. Forbes, our “cherished dogma” of non-Lamarckian inheritance still holds strong, and you’ve done your readers a disservice by implying otherwise. Lamarckism is not a “heresy,” but simply a hypothesis that hasn’t held up, despite legions of evolution-revolutionaries who argue that it flushes neo-Darwinism down the toilet. If “epigenetics” in the second sense is so important in evolution, let us have a list of, say, a hundred adaptations of organisms that evolved in this Larmackian way as opposed to the old, boring, neo-Darwinian way involving inherited changes in DNA sequence.
Forbes can’t produce such a list, because there’s not one. In fact, I can’t think of a single entry for that list.
Despite having quoted Coyne with approval, I am still going to read the book. Although epigenetics may leave neo-Darwinism unscathed, it matters for economics – and people’s welfare. A single generation matters. If epigenetics suggests that some effects are more persistent or have an effect in the next generation, it is an important consideration. For example, will the current famine in East Africa be felt for one generation or two?