Nutrient-dependent non-random personality differences
June 12, 2014 | James Kohl
Description: “Benjamin de Bivort, of Harvard, explores what fruit flies can tell us about personality, and also the random differences that develop between individuals and can’t be explained by genetics or environment.”
My comment: The differences are not random. The behavior of the flies exposed to a light stimulus does not address the conserved molecular mechanisms of insect behavioral development, which are nutrient-dependent and pheromone-controlled. For example, the complex wiring of the brain begins in insect larvae. See Nutrient-Sensing Neurons
Excerpt: “…Léopold’s group has found a path from food stimulus to behavior that is faster than predicted.”
My comment: The nutrient-dependent behavior is linked to ingestion of amino acids and a change in three dopamine-secreting neurons. In my model, nutrient-dependent amino acid substitutions stabilize cell type differentiation in the dopaminergic neurons and all other cell types. That means the adult behavioral response to light reflects changes in the diet of the larvae, which are associated with feedback that epigenetically may effect the amino acid substitutions during life cycle transistions of organisms. Those changes result in transgenerational epigenetic inheritance of morphological and behavioral phenotypes during the development of offspring.
That fact links the ability of nutrient-sensing larvae to adult behavior via conserved molecular mechanisms of amino acid dependent alternative splicings of pre-mRNA, which link the epigenetic landscape to the physical landscape of DNA in the organized genomes of all species.
See also: Mechanism explains complex brain wiring
Conclusion: “These results indicate for the first time the significance of why different sets of the same protein variations can occur in one neuron and it could explain mechanistically how this contributes to the complex wiring in our brain.
Although this research was done with fruit flies, it also provides new insights that help explain the wiring and complex interactions of the human brain and shine a new light on neurological development disorders such as autism. Thorough knowledge of nerve cell creation and their neural interactions is considered essential knowledge for the future possibility of using stem cell therapy as standard treatment for certain nervous system disorders.”
Journal article excerpt: “The Dscam1 gene uses combinatorial alternative splicing to generate tens of thousands of different receptor isoforms…”
The link from the experience-dependent de novo creation of olfactory receptor genes via alternative splicings of pre-mRNA to nutrient-sensing neurons in insect larvae suggests the different receptor-mediated behavioral responses of immature and mature organisms are not random and that they are nutrient-dependent and pheromone-controlled.
In my model, food odors associated with nutrient uptake prompt the combinatorial alternative splicings that generate different receptor isoforms, which enable seemingly futile cycles of thermodynamically-regulated protein biosynthesis and degradation that facilitate organism-level thermoregulation in ever-changing ecologies. Ecological adaptations are not manifested in data indirectly associated with visual input, because chemical ecology is the driving force behind ecological adaptations. That does not justify referring to the ecological adaptations as if they resulted from “random” changes.
See for example: Nutrient-dependent / Pheromone-controlled thermodynamics and thermoregulation and my video representation of how non-random personality differences arise.
The ability of flies and humans to detect amino acid concentrations in food throughout their life cycle transitions matches the development of the brain to personalities that are most likely to exemplify ecological adaptations in the absence of mutations or other factors that perturb protein folding — like nutrient-stress and social stress that alter hormone-organized and hormone-activated behaviors in vertbrates and invertebrates. Biophysically-constrained ecological adaptations prevent random differences in personality from achieving species-wide fixation in any species.