Mutated or receptor-mediated skin color

  • Home Genetics January 3, 2014

Studies of a skin color gene across global populations reveal shared origins

Excerpt: “All instances of a gene mutation that contributes to light skin color in Europeans came from the same chromosome of one person who most likely lived at least 10,000 years ago…”

SLC24A5, a Putative Cation Exchanger, Affects Pigmentation in Zebrafish and Humans

Excerpt: “We noted that the G and A alleles of the single nucleotide polymorphism (SNP) rs1426654 encoded alanine or threonine, respectively, at amino acid 111 in the third exon of SLC24A5.”

My comment: The key contributor to the chromosomal rearrangements that led to the skin color difference between Europeans and West Africans that arose 10,000 years ago is one amino acid in the gene SLC24A5. The amino acid substitution is reported as if it were a mutation. However, the human ortholog is highly similar in sequence and functional in zebrafish. If the human ortholog was highly similar in sequence and was functional in a bird species, we could compare chromosomal rearrangements in zebrafish, humans, and birds via conserved molecular mechanisms of nutrient-dependent pheromone-controlled ecological adaptations. For example, see:  Difference in Plumage Color Used in Species Recognition between Incipient Species Is Linked to a Single Amino Acid Substitution in the Melanocortin-1 Receptor and Estrogen receptor α polymorphism in a species with alternative behavioral phenotypes. However, few people seem to think in terms of conserved molecular mechanisms in species from microbes to man that link single amino acid substitutions to cell types and chromosomal rearrangements in individuals of different species. Instead, mutation-driven evolution seems to be what people think occurs in different species via mutations that result in color differences in fish, birds, and humans.

The fact that the mutated or receptor-mediated skin color differences in humans appear to have rapidly arisen as a result one fixed mutation ~50,000 years ago,  that required another another mutation to fix the change in the genome about 10,000 years ago, attests to the ridiculous power attributed to mutation-driven evolution, which requires two fixed mutations, without explaining how the lighter mutated skin color was naturally selected.  For comparison to the ridiculous lack of theoretical explanatory power, increased vitamin D in the diet seems likely to explain the change as does the need to produce more vitamin D via the change to nutrient-dependent pheromone-controlled receptor-mediated skin color.


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