Big brains are not all in the genes

Big brains are all in the genes

Nov 28, 2013 by Marie Daniels

Excerpt: “We found that brain size variations are associated with changes in gene number in a large proportion of families of closely related genes. These gene families are preferentially involved in cell communication and cell movement as well as immune functions and are prominently expressed in the human brain. Our results suggest that changes in gene family size may have contributed to the evolution of larger brains in mammals.”

My comment: Cell communication, cell movement, and immune functions are nutrient-dependent. In species from microbes to man the metabolism of nutrients to species-specific pheromones controls the physiology of reproduction. Thus, brain size is a function of nutrient-dependent pheromone-controlled niche construction that starts with ecological and social niche construction that leads to neurogenic and socio-cognitive niche construction in a continuum of adaptations to the sensory environment that facilitate survival of species and their diversification. The diversiification of brain size is nutrient-dependent and pheromone-controlled.

Journal article conclusion: “…variations in GFS associated with encephalization provided an evolutionary support for the specific cellular, physiological and developmental demands associated with increased brain size in mammals.”

If “Big Brains Are All in the Genes” was an appropriate title, variations would not merely be associated with what most people know are epigenetic effects of the sensory environment on biophysically constrained specific cellular, physiological, and developmental changes that link the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man via conserved molecular mechanisms. Thus, what’s represented in the journal article, and more explicitly in the journalist’s report is akin to “Evolution for Dummies” in which genes are determinants of brain size, albeit outside the context of olfactory/pheromonal input that alters ecological, social, neurogenic, and socio-cognitive niche construction. For comparison to an accurate representation of organismal complexity specific to the brain in primates, see: MicroRNA-Driven Developmental Remodeling in the Brain Distinguishes Humans from Other Primates

Epigenetically-effected tissue-specific changes in the expression of trans-regulators, such as microRNA, rather than sequence changes in cis-regulatory regions, are the driving force underlying developmental remodeling across hundreds of genes. Thus, big brains are not all in the genes. If anything was all in the genes, it would not involve remodeling due to changes in the microRNA/messenger RNA balance that result in difference in human and non-human primate brains, insect brains, and in nematode neurogenic niche construction. See also: Primate Transcript and Protein Expression Levels Evolve Under Compensatory Selection Pressures.

The compensatory selection pressures are, of course, nutrient-dependent and pheromone-controlled.

About James V. Kohl 1308 Articles
James Vaughn Kohl was the first to accurately conceptualize human pheromones, and began presenting his findings to the scientific community in 1992. He continues to present to, and publish for, diverse scientific and lay audiences, while constantly monitoring the scientific presses for new information that is relevant to the development of his initial and ongoing conceptualization of human pheromones. Recently, Kohl integrated scientific evidence that pinpoints the evolved neurophysiological mechanism that links olfactory/pheromonal input to genes in hormone-secreting cells of tissue in a specific area of the brain that is primarily involved in the sensory integration of olfactory and visual input, and in the development of human sexual preferences. His award-winning 2007 article/book chapter on multisensory integration: The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences followed an award winning 2001 publication: Human pheromones: integrating neuroendocrinology and ethology, which was coauthored by disinguished researchers from Vienna. Rarely do researchers win awards in multiple disciplines, but Kohl’s 2001 award was for neuroscience, and his 2007 “Reiss Theory” award was for social science. Kohl has worked as a medical laboratory scientist since 1974, and he has devoted more than twenty-five years to researching the relationship between the sense of smell and the development of human sexual preferences. Unlike many researchers who work with non-human subjects, medical laboratory scientists use the latest technology from many scientific disciplines to perform a variety of specialized diagnostic medical testing on people. James V. Kohl is certified with: * American Society for Clinical Pathology * American Medical Technologists James V. Kohl is a member of: * Society for Neuroscience * Society for Behavioral Neuroendocrinology * Association for Chemoreception Sciences * Society for the Scientific Study of Sexuality * International Society for Human Ethology * American Society for Clinical Laboratory Science * Mensa, the international high IQ society