Color vision as we know it resulted from one fortuitous genetic event after another.
October 1, 2014|
Excerpt 1: “The fact that we have the same few amino-acid substitutions as New World monkeys argues there was a single ancestral variation that gave rise to [the cone opsins of] both Old and New World primates,” Nathans says. “It leads to an interesting twist on the evolutionary dogma of gene duplication.”
My comment: The fact that amino acid substitutions differentiate all cell types in all individuals of all species has not caused evolutionary theorists to change their claims. It has become perfectly clear that nutrient-dependent RNA-directed DNA methylation links the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man via RNA-mediated events. But theorists still seem to think in terms of mutation-initiated natural selection and the evolution of biodiversity. The fact that biodiversity is nutrient-dependent and controlled by the metabolism of nutrients to species-specific pheromones, which control the physiology of reproduction, is not considered even though evolutionary theorists have never described a biologically-based evolutionary event.
Excerpt 2: “Were it not for this little monkey and the series of genetic events that created it, we might not have the color vision we do…”
My comment: What series of genetic events created anything? Genes have no creative power; evolutionary events have no creative power. “…natural selection is an evolutionary process initiated by mutation. It does not have any creative power…(p. 196)
Excerpt 3: “Then, an allele of one of the opsin genes mutated, producing a pigment protein that responded to previously unseen wavelengths of light.”
My comment: To my knowledge, there is no experimental evidence of biologically-based cause and effect that supports that assumption, or any of the other assumptions throughout the text of this article.
Excerpt 4: “A single nucleotide change can change your color vision.”
My comment: Is someone claiming the single nucleotide change (SNP) was caused by a mutation? Is there a model that links the SNP to color vision? The statement links changes that appear to have automagically occurred.
Excerpt 5: “The results provided support for the idea that an ancient X-linked opsin gene underwent a single duplication event and that subsequent mutations in the copy shifted the absorbance spectrum of the photopigment.3”
My comment: Gene duplication events are nutrient dependent. They are not caused by mutations and gene duplications or mutation-driven losses of functional genes do not lead to subsequent mutations. Nutrient-dependent gene duplication is controlled by the metabolism of the nutrients to species specific pheromones in species from microbes to man.
Facts about what is portrayed as The Rainbow Connection.
Loss of Olfactory Receptor Genes Coincides with the Acquisition of Full Trichromatic Vision in Primate That fact links RNA-directed nutrient-dependent DNA methylation and RNA-mediated events from ecological variation to amino acid substitutions and to gains and losses of protein function, which differentiate all cell types of all individuals of all species.
See for example: “…the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla.” Dobzhansky (1973)
“RNA molecules function as the central conduit of information transfer in biology.” That fact suggests theories about how color vision arose are based on assumptions linked to the invention of neo-Darwinism via the gene-centric approach of population geneticists who knew nothing about RNA-mediated events when they began to invent their theories.
It is surprising to see those theories integrated into this article as if they suddenly had any explanatory power given what is currently known about Alternative RNA Splicing in Evolution and about Nutrient-dependent/pheromone-controlled adaptive evolution: a model.
Until recently others have made claims like “…the evolution of trichromacy as well as huge increases in social complexity have minimised the role of pheromones in the lives of primates, leading to the total inactivation of the vomeronasal system in catarrhine primates while the brain increased in size and behaviour became emancipated from hormonal regulation.” No experimental evidence of biologically-based cause and effect linked from biophysical constraints on amino acid substitutions and protein folding to cell type differentiation supports claims like that, either.
Re: “The results provided support for the idea that an ancient X-linked opsin gene underwent a single duplication event and that subsequent mutations in the copy shifted the absorbance spectrum of the photopigment.3”
It’s not a good idea to suggest that the idea above has been supported by any experimental evidence that might otherwise link biologically-based cause and effect across species. First, sex differences in cell types must be explained. For example: “Small intranuclear proteins also participate in generating alternative splicing techniques of pre-mRNA and, by this mechanism, contribute to sexual differentiation in at least two species…”
The bottom line appears to be that people willingly accept theories about how sex differences arose and about how color vision arose because they think the theories have been supported by experimental evidence. But, the experimental evidence links ecological variation to ecological adaptations via conserved molecular mechanisms in species from microbes to man. Until biologically-based evolutionary events are described that link mutations to the amino acid substitutions that differentiate cell types associated with color vision, I hope that others will begin to examine details of RNA-mediated events that link cell type differentiation in all species from nutrient uptake to the pheromone-controlled physiology of reproduction and controlled biodiversity, which is loosely associated with color vision in: The Rainbow Connection
Close associations between frugivory in species that are blind as bats and cave fish link nutrient uptake in an atoms to ecosystems context that also links species-specific pheromones to control of cell type differentiation in the honeybee model organism and all other model organisms. Primates should not be excluded from an atoms to ecosystems model of ecological variation linked to ecological adaptations via RNA-mediated events.