Subscription required: Science 15 March 2013: Vol. 339 no. 6125 pp. 1312-1316
DOI:10.1126/science.1233213
Adaptive Evolution of Multiple Traits Through Multiple Mutations at a Single Gene
Catherine R. Linnen, Yu-Ping Poh, Brant K. Peterson, Rowan D. H. Barrett, Joanna G. Larson, Jeffrey D. Jensen, Hopi E. Hoekstra
Abstract Excerpt: “…local adaptation is the result of independent selection on many mutations within a single locus, each with a specific effect on an adaptive phenotype, thereby minimizing pleiotropic consequences.”
My comment (submitted 3/14/13 approved 4/5/13):
In the context of adaptive evolution, Linnen et al.,reminds us to look at models of genes with large effects for comparison to random mutations theory. For example, using the molecular mechanisms common to all species and exemplified in the mouse, the time from pleiotropy to epistasis in a human population appears to be approximately 30,000 years (Kamberov et al., 2013; Grossman et al., 2013). Perhaps epistasis requires only one nutrient-dependent pheromone-controlled amino acid substitution. That likelihood led me to look at pleiotropy, amino acid substitutions, and epistasis in several different model organisms via the common molecular mechanisms of “Nutrient-dependent / Pheromone-controlled thermodynamics and thermoregulation.”
I moved quickly from microbes to nematodes, insects, and mammals. Receptor-mediated mouse to human examples of how nutrient-dependent amino acid substitutions can be readily linked to pheromone-controlled reproduction via common molecular mechanisms become as clear as they are in the honeybee model organism. What the queen eats determines her pheromone production and everything else about the interactions in the colony, including the development of the worker bees brain. The epigenetic effects occur sans mutations, which tends to refute the multiple mutations approach to adaptive evolution and replace theory with a model. In the model, natural selection is for nutrients that metabolize to pheromones. The pheromones control reproduction and link epigenetic effects on the microRNA/messenger RNA balance from stochastic gene expression to behavior and back.
