Here’s a link to a Science Daily article on epigenetics. The authors report that the known and studied method of epigenetic marking, methylation of Histone3=H3, is not only passed down from one cell generation to another during development, but that these epigenetic markings are passed on from one generation of organisms to the next.
These findings suggest that the neo-Darwinian mechanisms normally invoked in evolutionary discussions may or may not be critical for “adaptation.” If further studies confirms the widespread phenomena of epigentic markings being handed down from generation to generation, then there may not be much force left to the evolutionary tales we’ve been told over the years.
What I mean is this. We are told that organisms, in their struggle for existence, must adapt to their environment, and that this adaptation to the environment is what drives evolution. IOW, organism A must out-compete organism B, and this is done through genetic variation, helped by NS. (Genetic drift also has some minor, or major, role to play as well; but it’s still ‘genetic variation’ we’re dealing with.)
But is that what we see here? That’s not what I see. What I see is an organism that does not change genetically; rather, the organism itself affects and changes gene expression by the “methylation” of portions of the DNA. So we don’t see the sequences of protein coding regions, nor even regulatory regions changing, but, instead, see the addition of methyl groups onto the DNA strands, and this ‘methylation’ being the cause of the needed “environmental” adjustment, or adaptation.
So, the picture this gives us is one of an organism that is already equipped to handle changes in its environment in a way that basically bypasses genetic variation, per se. This gives the impression that within the organism itself, needed “adaptations” to its environment can already be found.
I’ll remind readers here of the lizards transplanted to a neighboring island in the Adriatic sea which, when looked at again 30 years later, were found to have undergone significant morphological changes including the appearance of cecal valves in their digestive system. This change can in no way be explained via genetic changes to its DNA (not enough time by a long shot); but, can, quite easily be explained via the type of epigentic changes the authors tracked in this study.
So, is this the scenario for “adaptive” change in many, if not most organisms: (1) the environment changes, (2) epigenetic markers change gene expression, and (3) “adaptation” is effected? Please not that in all of the above, there is no searching for some kind of ‘genetic’ solution taking place. SNPs of all types, gene duplication, recombination, etc, have nothing to do with any of this. The organism intrinsically has the propensity of dealing with a changed environment—much as a Designer would who was designing some form of life which had to deal with changing environmental conditions. It strikes one of what James Shapiro calls “natural engineering.”
Well, if the “environment” is tied to ‘epigenetic markers’ and not to ‘genetic variation’ as the means of “adapting” to the environment in an “heritable” way, then, as I ask in the title of the post: what’s left of Darwinism? Base changes to the DNA is out. A direct connection between the environment and base changes to the DNA is out. You can’t even answer NS is at work since nothing is being “selected,” but, rather, the “adaptive solution” is simply being ‘handed down.’ So, while all the neo-Darwinian mechanisms evolutionists invoke do happen, and do have roles to play in certain kinds of adaptations, much of what passes as “microevolution” must now be significantly re-evaluated.
Another Day; Another Bad Day for Darwinism.