Outside-in mutation-initiated origins

In the nematode Pristionchus pacificus, tooth formation is triggered by starvation, which links it to nutrient-dependent pheromone-controlled reproduction in species from microbes to man via ecological, social, and neurogenic niche construction.

The system-wide rewiring that underlies behavioral differences in predatory P. pacificus and bacterial-feeding C. elegans exemplifies the link from the nutrient-dependent pheromone-controlled neurogenic niche construction in nematodes to  nutrient-dependent pheromone-controlled neurogenic niche construction in humans. Every aspect of all adaptations involved in niche construction begins with nutrient-dependent ecological niche construction, which occurs from the inside-out via nutrient uptake-driven morphogenesis.

However, what often happens, at the same time my posts to the National Geographic site are blocked, is that their writers favor explanations that do not fit with what is known about conserved molecular mechanisms. Instead, they seem to favor theories like mutation-driven evolution, in which the story of the first teeth is like the story of the “Tooth Fairy.”  Outside-in formation of teeth, presumably might occur via mutation-initiated natural selection, but there is no experimental evidence for that theory. Similarly, there is no experimental evidence that suggests the “Tooth Fairy” is an accurate representation of biological facts.

The teeth in our mouth started out as teeth in worms, not as body armor. There’s a model for that! Nutrient-dependent/pheromone-controlled adaptive evolution: a model

Excerpt  1) “Clearly, however, the epigenetic effects of food odors and pheromones are involved in neurogenic niche construction as exemplified in nematodes (Bumbarger, Riebesell, Rödelsperger, & Sommer, 2013), and in flies (Swarup et al., 2013).”

Excerpt 2) “Differences in the behavior of nematodes are determined by nutrient-dependent rewiring of their primitive nervous system (Bumbarger et al., 2013). Species incompatibilities in nematodes are associated with cysteine-to-alanine substitutions (Wilson et al., 2011), which may alter nutrient-dependent pheromone production.”

But see for comparison: “…teeth seem to have evolved through the extension of odontogenic competence from the external dermis to internal epithelium soon after the origin of jaws.”

And see also: “Against this prevailing trend, our conclusion is based on a revised analysis of traditional morphological features of both discrete conodont elements and apparatuses, histological investigation and a revised cladistic analysis modifying that used in the keystone publication promoted as proof of the hypothesis that conodonts are vertebrates.

Note, however, that the outside-in origin of teeth correlates well with the outside-in origin of differences in finches beaks that were somehow linked to avian reproduction before the discovery of pheromones in birds that link “The microbiota-gut-brain axis: neurobehavioral correlates, health and sociality”  of birds to its nutrient-dependent pheromone-controlled adaptive evolution via conserved molecular mechanisms in species from microbes to man.

See my comment to the Frontiers in Integrative Neuroscience site and the author’s response.

Can you think of any reason why National Geographic would not want to post my responses to their science journalist’s interpretations of research results?


Author: James Kohl

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