A microRNA-mediated mechanism that is epigenetically inherited
August 8, 2014 | James Kohl
The stressors a female rat experiences during pregnancy can have repercussions for her granddaughters, a study shows.
August 7, 2014|
Excerpt: “These changes could be the result of a microRNA (miRNA)-mediated mechanism, which may be epigenetically inherited across generations.”
There is currently no alternative explanation for these changes. However, a model of how nutrient-dependent pheromone-controlled amino acid substitutions link cell type differentiation (e.g., from the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man via conserved molecular mechanisms) explains how nutrient-dependent changes in the microRNA/messenger RNA balance cause effects on hormone-organized behaviors that also are affected by hormones.
Yes, it’s complicated! However, the link from ‘effect’ to ‘affect’ was explained in Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Bruce McEwen also focussed on the difference between ‘effect’ and ‘affect’ in a correction to Brain on stress: How the social environment gets under the skin
Simply put, evolutionary theorists must realize that ecological variation and nutrient uptake are required for changes to the microRNA/messenger RNA balance. Those changes result in cell type differentiation via amino acid substitutions, which stabilize DNA in organized genomes. Until evolutionary theorists begin to think in terms of biophysically-constrained protein folding, they may continue to tout the pseudoscientific nonsense of mutation-initiated natural selection and the evolution of biodiversity.
Fortunately, serious scientists know that mutations perturb protein-folding, which means that mutations do not stabilize DNA in organized genomes. That’s why mutations cannot be linked from ecological variation to epigenetic effects on hormones that affect behavior manifested in increasing organismal complexity associated with morphological phenotypes.
Clearly, the evolutionary theorists can explain differences in morphological phenotypes that arise from mutations. But the fact that they cannot explain how mutations could effect hormones, which affect behavior, leaves some serious scientists wondering.
In the early 1990s, I began to wonder why the theorists were unable to think in terms of olfactory/pheromonal input, which we now know epigenetically effects hormones that obviously link ecological variation to ecological adaptations via affects on behavior. Recently, it has become clearer that evolutionary theorists cannot think about anything outside the context of mutation-initiated natural selection and the evolution of biodiversity. Some of them are even attempting to re-invent their theories using the term “epimutation.”
I hope that serious scientists will stop that pseudoscientific nonsense before it becomes accepted as if it were based on any experimental evidence of biologically-based cause and effect whatsoever. See for comparison: Nutrient-dependent/pheromone-controlled adaptive evolution: a model The model includes examples from different species that attest to facts about how amino acid substitutions link a microRNA-mediated mechanism that is epigenetically inherited from ecological variation to nutrient-dependent pheromone-controlled ecological adaptations, without any nonsense about mutation-driven evolution.
For contrast: Nei (2013) wrote: “…genomic conservation and constraint-breaking mutation is the ultimate source of all biological innovations and the enormous amount of biodiversity in this world.”
That’s nonsense! Ecological variation in the supply of nutrients leads to the nutrient-dependent pheromone-controlled physiology of reproduction and nutrient-dependent ecological adaptations manifested in the inherited morphological and behavioral phenotypes of species from microbes to man.