The Death of Darwinian Evolution

The collapse of Darwinian Evolution may well be on the horizon.

No, I haven’t suddenly embraced Creationism and I’m being more than a little overly dramatic, but the science of Epigenetics may well cause us to rethink a lot of our current ideas about evolution.

Jean-Baptiste Lamarcke (1744-1829) had hypothesized that animals could pass on traits they had acquired during their lifetime to their descendents. This idea for an evolutionary mechanism was abandoned when Darwin proposed Natural Selection. Now however scientists are taking another look at Lamarcke due to what is known as Epigenetics.

Epigenetics deals with how strongly, or weakly, genes express themselves due to environmental factors through what are known as “epigenetic marks.” These differences in gene expression appear to be controlled by the cellular material, the “epigenome,” that sits on top of the genome.

Environmental factors such as diet, stress and prenatal nutrition appear to be able to impact the epigenetic marks and turn genes on, turn them off, and adapt how strongly they assert themselves. Even more interestingly, it appears these marks can leave an imprint on genes that can be passed to succeeding generations at least temporarily.

This is pretty wild stuff. It means that adaptation to severe environmental changes, which would be a form of stress, could occur within a generation and the adaptation could be passed on to succeeding generations as long as the environmental change persisted and perhaps even longer.

This would also explain many of the observed differences in identical twins despite the fact that they have the exact same DNA.

This adaptation occurs without changing the gene so no mutation is required. The question of course becomes can these epigenetic adaptations become permanent or can they guide or influence genetic changes to match the epigenetic adaptation as a sort of directed evolution?

This could reduce the time scale of evolutionary change from millions of years to a few generations and allow rapid adaptation to a rapidly changing environment.

Of course, before we get carried away here, there is as yet no evidence that epigenetic adaptations can be permanent or can direct genetic change. But that sure would resolve some issues with how some life managed to survive rapid environmental change.

I can hear the creationists now saying how epigenetics allowed the emergence of the millions of individual species from the “Kinds” that were loaded on the Ark and, interestingly enough, that would be a better argument than the super evolution they claim at the moment.

Epigenetic adaptation lines up better with Punctuated Equilibrium than Phyletic Gradualism so, possibly, two points for Gould and Eldridge.

Of course Natural Selection doesn’t go away, it simply gets another new partner to help strengthen the Theory of Evolution.