Nutrient uptake is responsible for the amino acid substitutions in organisms that have adaptively evolved to their sensory environment via the epigenetic effects of olfactory/pheromonal input and changes in intercellular signaling that result in stochastic gene expression detected in genome-wide scans of individual and species-wide phenotypic diversity. The link to the immune system of mammals is via gonadotropin releasing hormone (GnRH) and its non-random experience-dependent controlled secretion. http://www.socioa...53/27989