One question with respect to epigenetics (traits acquired during a life form’s existence that become part of the genes and can get passed on) is, how long do these epigenetics changes persist? In the case of water fleas and pollution,
Dr Stewart Plaistow, a Senior lecturer in Evolutionary Biology at the University of Liverpool, explains: “Epigenetic inheritance mechanisms are controversial in evolutionary biology at the moment because they provide a possible mechanism for the inheritance of environmental effects alongside traditional Darwinian inheritance.
“Although they are routinely demonstrated in plants they are much more controversial in animals because epigenetic marks are often thought to be wiped clean during embryo development.”
In this study, the researchers looked at one important epigenetic mark, the methylation of cytosine in DNA, in the water flea Daphnia pulex.
They demonstrated that exposure of water fleas to low doses of pollutants had effects on the epigenome that persisted for 15+ generations.University of Liverpool, “Epigenetic effects of pollution persist for multiple generations in water fleas” at ScienceDaily (February 10, 2022)
Well, that’s revealing, isn’t it? The evolutionary biologist admits that epigenetics is controversial, not because it can’t be demonstrated (it can) but because it provides competition for “traditional Darwinian inheritance.”
In a way, it’s understandable. If evolutionary biologists must reckon with epigenetics as a cause of genetic changes, they can’t just confidently ascribe them to Darwinian evolution. But who said life was always easy?
The paper is open access.
See also: Epigenetic change: Lamarck, wake up, you’re wanted in the conference room!