Brain circuits: rewiring via constant turnover of RNA molecules

Researchers discover how brain circuits can become miswired during development arises in the context of Regulation of Axon Guidance by Compartmentalized Nonsense-Mediated mRNA Decay.

News article excerpt:“The idea that control of brain wiring is located in these RNA molecules that are constantly being dynamically turned over is something that we didn’t anticipate,” Dr. Jaffrey adds. “This tells us that regulating these RNA degradation pathways could have a tremendous impact on brain development.

My comment: In my model, thermodynamically “futile” cycles of RNA transcription and degradation are responsible for changes in pheromone production that enables accelerated changes in nutrient-dependent adaptive evolution of the human brain and behavior, which is controlled by the microRNA/messenger RNA (miRNA/mRNA) balance and organism level thermoregulation. The nutrient-dependent miRNA/mRNA balance controls ‘seemingly futile’ cycles of RNA-dependent protein biosynthesis and degradation (i.e., of nutrients to species-specific pheromones).

Under conditions of life that include nutrient-dependent / pheromone-controlled thermodynamics and thermoregulation, disordered protein degradation is not likely to be due to mutations (e.g., as commonly indicated). Instead, environmental cues, like those that signal the availability of glucose, cause changes in the miRNA/mRNA balance. The changes enable controlled de novo gene expression and also the regulation of gene expression during developmental transitions required for successful nutrient-dependent reproduction in species from microbes to man.

Mutations perturb both the control and the regulation of protein biosynthesis and degradation. That’s why mutations do not contribute to adaptive evolution. Instead, nutrient metabolism to pheromones controls nutrient-dependent reproduction and stabilizes intracellular signaling and the internuclear interactions of the genome to prevent the runaway selection for mutations  in mutated organisms, which obviously never occurs.

I suspect that the idea of runaway selection for mutations comes at us via the imaginations of those who prefer thoughts of the ‘Zombie Apocalypse’ to biological facts. For example, Jay R. Feierman, who is the moderator of the International Society for Human Ethology‘s discussion group, claims that “…natural selection is never for nutrients…” and touts the ridiculous mutations theory of evolution that will almost undoubtedly lead us closer to the Apocalypse.

Feierman: Random mutations are the substrates upon which directional natural selection acts.” I’ve asked: Is there a model for that, while knowing that in reality, there’s not even a theory that addresses it.

Darwin, albeit without knowing anything about genetics or epigenetics,  clearly inferred that ‘conditions of life’ in all species are nutrient-dependent and pheromone-controlled. I think he anticipated intuitive agreement (e.g., all organisms must eat and reproduce for natural selection to occur) rather than the statistical bastardization of his theory that followed. It is that statistical bastardization that I think led to an inability to anticipate how the constant turnover of RNA molecules contributes to typical adaptively evolved brain development and to atypical brain development.

See for comparison to biological facts consistent with Darwinian theory: Farh KK, Grimson A, Jan C, Lewis BP, Johnston WK, Lim LP, Burge CB, Bartel DP: The widespread impact of mammalian MicroRNAs on mRNA repression and evolution. Science 2005, 310:1817-1821. Their conclusion: “… it is hard to escape the conclusion that miRNAs are influencing the expression or evolution of most mammalian mRNAs.”

Feierman: Hello James (Kohl), Although I usually don’t respond to your posting, I will this time to see if it can be productive.

Feierman’s unproductive response results from his denial of the epigenetic cause and effect that I have detailed in my model. His denial now extends to blocking my posts to the ISHE’s group, with claims that they include redundant information. What’s redundant is his touting of random mutations theory, which can be readily dismissed when one learns how to integrate the basic principles of biology and levels of biological organization required to link sensory cause directly to epigenetic effects on adaptively evolved behaviors in species from microbes to man. For example, see: Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338. DOI: 10.3402/snp.v2i0.17338.

Author: James Kohl

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