Excerpt: “…the glycoprotein Reelin is crucial to developing healthy neural networks. Logically, taking away the two receptors that Reelin is known to act on early in the brain’s development should create the same malformations as taking away Reelin itself. It didn’t.
My comment: Differences in glucose metabolism lead to differences in cell types via receptor-mediated behavior. Mutated receptors are ecological dead ends because perturbed protein folding does not benefit any organism of any species with differentiated cell types that are nutrient-dependent and pheromone-controlled. Nutrient-dependent cooperation is required and it is not mutation-driven.
My comment: The link from this article to information on eye regression and schooling in blind cave fish establishes the fact that schooling is nutrient-dependent in fish. It may not depend on visual input, since changes that occur downstream of sensory input must first somehow be linked to epigenetic effects of sensory input. There is no known link between visual input and the epigenetic effects that might change genetic loci. The epigenetic landscape becomes the physical landscape of DNA in the organized genomes of species from microbes to man via olfactory/pheromonal input. That fact is consistent with experimental evidence reported as:
Excerpt: “Schooling behavior in A. mexicanus has evolved both through changes in sensory systems and through changes in genetic loci that likely act downstream of sensory inputs.”
My comment: However, it should be clear that schooling behavior has not evolved in the context of mutation-driven evolution of eyes or eye regression in cave fish. Schooling behavior is nutrient-dependent and pheromone controlled as is the social behavior of all species. That explains why “Cavefish have lost the tendency to school regardless of vision.” In their nutrient-poor environment that led to eye regression, it also led to deficits in signaling by pheromones that enables schooling.
Summary: “Genetic analysis of behavior can also reveal associations between behavior and morphological or neural phenotypes, providing insight into the proximate mechanisms that control behavior.” The proximate mechanisms that control behavior are not mutation-driven in the context of mutation-driven evolution. Proximate mechanisms are nutrient-dependent and pheromone-controlled. They enable differences in nutrient availability to determine ecological adaptations via the pheromone-controlled physiology of reproduction in species from microbes to man.
See also: Nutrient-dependent / Pheromone-controlled adaptive evolution: (a mammalian model of thermodynamics and organism-level thermoregulation) — video excerpt.