May 15th, 2013 in Biology / Cell & Microbiology
Excerpt: “Understanding the concept of morphogen gradients—the mechanism by which a signal from one part of a developing embryo can influence the location and other variables of surrounding cells—is important to developmental biology, gene regulation, evolution, and human health.”
My comment: I am reminded by the content of this articlethat I have not yet published a preprint about nutrient-dependent pheromone-controlled morphogenesis in species from microbes to man. As most of you know, however, nutrient-dependent pheromone-controlled morphogenesis is included in my model of nutrient-dependent pheromone-controlled adaptive evolution.
Although I find no fault with the portrayal of morphogenesis in the fruit fly model, I will note that nutrient-dependent pheromone-controlled morphogenesis is probably best exemplified at the advent of sexual reproduction in yeast. See: Pheromone-Induced Morphogenesis Improves Osmoadaptation Capacity by Activating the HOG MAPK Pathway and see also: Feedback between Population and Evolutionary Dynamics Determines the Fate of Social Microbial Populations. An alternative invertebrate representation can be found in Ecological selection as the cause and sexual differentiation as the consequence of species divergence?
Taken together it has become perfectly clear that natural selection and nutrient-dependent ecological divergence precedes sexual divergence and pheromone-dependent sexual selection in the only model of adaptive evolution that incorporates what is currently known about the conserved molecular mechanisms of epigenetic cause and effect (e.g., among microbes; among populations of flightless crickets confined to the Virgin Islands; and in a human population that arose during ~30,000 years in central China).