Gene duplication: integrating nutrient availability and physiology
October 3, 2013 | James Kohl
My comment on Following Gene Duplication, Paralog Interference Constrains Transcriptional Circuit Evolution has been approved. It addresses pheromone-signaling in the context of the methods and protocols of experiments that have eliminated any further consideration of mutations theory whatsoever.
In Kondrashov’s “Gene duplication as a mechanism of genomic adaptation to a changing environment,” olfactory receptor proteins are one of the main duplicated gene families. This suggests duplication leads to an increase in sensitivity to a particular odor, which may be adaptive under certain conditions. For example, duplication of an olfactory receptor that enables increased glucose uptake in starving yeasts is adaptive. However, in well-nourished yeasts, control of de novo olfactory receptor gene creation by the metabolism of nutrients to species specific pheromones helps to ensure the organisms do not out-reproduce their food supply. Thus, the first example of nutrient-dependent pheromone-controlled adaptive evolution is apparent in Schmidt (2013) “Signaling Crosstalk: Integrating Nutrient Availability and Sex.”
This signaling crosstalk is also exemplified in the conserved molecular mechanisms of nutrient-dependent amino acid substitutions in nematodes, insects, other mammals, and humans. The substitutions link species-specific morphogenesis and the metabolism of nutrients associated with other sensory input to the species-specific pheromone-controlled physiology of reproduction.
For contrast, no experimental evidence links mutations and population-wide fixation of new alleles. Thus, it becomes clear that adaptive evolution is nutrient-dependent and pheromone-controlled sans mutations.
This leaves some evolutionary theorists waiting for other theoretical models to automagically appear. For example, Chelo et al (2013) conclude: “But our results show that further empirical work and more theoretical models are required to accurately predict the fate of that allele over long time spans.”
Meanwhile, experimental evidence of conserved molecular mechanisms that link the epigenetic ‘landscape’ to the physical landscape of DNA in the organized genomes of species from microbes to man has shown that fixation of new alleles is nutrient-dependent and pheromone-controlled. This brings up the question of why anyone would wait for theoretical models to explain what is already known about evolution. It’s nutrient-dependent and pheromone-controlled, which is consistent with Darwin’s ‘conditions of life’ but not with Haldane’s or any other theory of mutation-driven evolution.
In Pheromone Signaling: Methods and Protocols, edited by Kazushige Touhara, we read in the Preface that “The notion of chemical communication was first proposed by Charles Darwin in the late nineteenth century, in conjunction with the physical signal-mediated communication described for the visual and auditory systems. At approximately the same time, Jean Henri Fabre described the attraction of male moths by conspecific females, and proposed that the cue was not a visual signal but some kind of smell. The concept of chemical interaction was scientifically recognized when Albrecht Beth proposed in 1932 the term “ectohormone” for substances that functioned like a hormone but were secreted into the external environment.”
However, by that time Haldane’s theory of mutation-driven evolution had already been accepted despite the fact that no experimental evidence supported the theory. Evolutionary theorists have largely refused to look back at what Darwin wrote, and have refused to accept the evidence from experiments in many different species that adaptive evolution is nutrient-dependent and pheromone-controlled. Many of them seem to still be living in the late nineteenth century but without Darwin’s insight or any other insight provided by neuroscientists in the twentieth and twenty-first centuries. Yet, those that are living in the past, with decades old ideas that were never scientifically supported are teaching your children and grand-children about what they were taught about the biology of cause and effect. But, what they are teaching is a ridiculous theory, not something that should continue being taught now that scientific evidence has shown the mutation-driven evolution is a ridiculous theory.