The Cambrian explosion (revisited)

ScienceVol. 341 no. 6152 pp. 1355-1356  DOI: 10.1126/science.1239450

  • Perspective / Earth Science

Causes of the Cambrian Explosion [subscription required] by M. Paul Smith and David A. T. Harper

Excerpt: “The rapid diversification of animals in the early Cambrian is likely to have been the result of a complex interplay of biotic and abiotic processes (see the first figure).”

My comment submitted to the Science site on 9/20/13 and approved on 9/24/13.

Thank you. There is now no question that the abiotic to biologically-based origin of the cascade involves the ability to acquire nutrient chemicals and to construct ecological niches. Ecological niche construction leads to social niche construction via the metabolism of nutrients to species-specific pheromones, which also control reproduction in all species. (Yes, even in birds.)

Ecological and social niche construction clearly lead to morphogenesis and neurogenic niche construction exemplified in nematodes that developed teeth in the transition from bacterial “grazing” to predation. Nutrient-dependent pheromone-controlled adaptive evolution then appears to be responsible for the earliest forms of socio-cognitive niche construction exemplified in brainless learning and memory.

Thus, the basis for the Cambrian explosion can be linked to an environmental drive that evolved from that of nutrient ingestion in unicellular organisms to that of pheromone-controlled socialization in insects sans mutations. In vertebrates we can see the progression from neurogenic niche construction in nematodes to construction of the invertebrate socio-cognitive niche, which reaches its pinnacle in mammals.

In mammals, food odors and pheromones epigenetically effect changes in hormone-organized and hormone-activated behaviors via hormones such as gonadotropin releasing hormone, luteinizing hormone and their downstream developmental affects on pheromone-controlled sexual behavior in nutrient-dependent reproductively fit individuals across species of vertebrates (Yes, again, even in birds.) Thus, the epigenetic effects of the sensory environment are linked to genes, behavior, and back via genetically predisposed species-specific behaviors that involve the physiology of reproduction.

Thanks again. The authors make no mention of mutations or any aspect of what might otherwise still be considered by evolutionary theorists to be mutation-driven evolution. Evidently they are aware of the experiments and recent report that mutations are not fixed in nematodes, which is why I mentioned the transition to predatory nematodes that clearly involves nutrient-dependent pheromone-controlled fixation of new alleles, not mutations.

Apparently, we can no more get to the Cambrian explosion via mutations than we can get to construction of our socio-cognitive niche without the central role of nutrient-dependent pheromone-controlled reproduction. That makes sense, doesn’t it?

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