John Hawks is an anthropologist we’ve often noted here. In his review of palaeobiologist Peter Ward’s LaMarck’s Revenge: How Epigenetics Is Revolutionizing Our Understanding of Evolution’s Past and Present (“Epigenetics upends natural selection and genetic mutation as the sole engines of evolution, and offers startling insights into our future heritable traits.”), Hawks has this to say about epigenetics:
Some scientists have hailed epigenetics as the future of biology, while others denounce it as an empty buzzword. Perhaps no other term inspires so much debate among scientists about how to define it.
But here’s the catch. When it comes to the fossil record, paleontologists have a different idea of “fast” from everyday life. Hundreds of thousands of years is plenty of time for Darwinian natural selection to have changed Lystrosaurus. We don’t need Lamarckian inheritance or epigenetics to explain it.
It’s not that there’s no evidence for the phenomenon. Experiments in mice have shown the potential, in some circumstances, of inheritance of induced epigenetic changes. But such changes last at most a few generations, and most studies have found no evidence for a directed effect. Instead, the life experiences of the parents exert mostly random effects on their offspring. Such effects may turn out to be important in understanding human health, but they are much more like Darwin’s notion of inheritance than Lamarck’s.
John Hawks, “‘Lamarck’s Revenge’ Review: Inheriting the Wrong Ideas” at Wall Street Journal (paywall)
Hawks gives the sense of a man trying to put out a fire. Hence the need to dump on the possibility that epigenetics can account for changes in evolution and then to claim epigenetics for the sacred name of Darwin.
The assertion that natural selection can account for complex, detailed changes, given enough time, is a mantra: That is, if specific probability calculations render that unlikely, so much the worse for probability theory.
Responses like this from a usually level-headed thinker mainly demonstrate that epigenetics is likely to upset quite a few applecarts.
Note: Readers may know of Ward as one of the authors of Rare Earth: Why Complex Life is Uncommon in the Universe
See also: Homo Naledi: Hawks accuses Shermer of murdering facts
Homo naledi’s small but sophisticated brain challenges belief in “an inevitable march towards bigger, more complex brains.”
John Hawks on human evolution: Free chapter from book on evolution from Princeton U