It was long known that almost every amino acid can be encoded by multiple synonymous codons and that every organism, from humans to fungi, has a preference for certain codons.
That fact underlies our representation of RNA-mediated cell type differentiation from our 1996 review From Fertilization to Adult Sexual BehaviorSee our section on molecular epigenetics. Our representation was subsequently linked to organization of genomes in insects and to life history transitions in honeybees and humans via single nutrient-dependent amino acid substitutions. Those links were fully established before microRNAs and adhesion proteins were linked via the octopus genome sequence from microbes to humans. All serious scientists now realize that the conserved molecular mechanisms of biophysically constrained RNA-mediated protein folding link the epigenetic landscape to the physical landscape of DNA in all living genera.
The finding is obviously very thought-provoking; for instance, it would indicate that in addition to eating “materials” (in the form of carbohydrates, proteins, etc), you are also eating “information” (as different miRNAs from distinct food sources could well bear different consequences on the regulation of host physiology once taken by the host due to potential regulation of different target genes as determined by the “information” contained within the miRNA sequence), thus providing a whole new dimension to “You are what you eat”.
My comment: Ecological variation leads to ecological adaptation via nutrient-dependent RNA-mediated protein biosynthesis and degradation in the context of biophysically constrained thermodynamic cycles of protein biosynthesis and degradation that link the physiology of reproduction to biodiversity via organism-level thermoregulation.Genes cannot adapt outside that context, which helps to explain why Darwin insisted his “conditions of life” be placed before “natural selection.” If Darwin had known about genes he probably would have linked epigenetic effects of food to ecological adaptation even without knowing about nutrient-dependent RNA-mediated gene duplication and RNA-mediated amino acid substitutions that stabilize the organized genomes of all living genera.His book title might have been “Life is RNA-mediated.”
See also: Life is physics and chemistry and communication and Life as physics and chemistry: A system view of biology and Top-down causation: an integrating theme within and across the sciences? and Physiology is rocking the foundations of evolutionary biology
If life is not RNA-mediated in the context of what is known to serious scientists about physics, chemistry, communication, biology, top-down causation, and the physiology of nutrient dependent reproduction, life may have somehow evolved to link metabolic networks to genetic networks in all cells of all individuals of all living genera. However, no evidence of biologically-based cause and effect links anything encoded by multiple synonymous codons to RNA-mediated gene duplications and the RNA-mediated amino acid substitutions that differentiate all cell types of all individuals of all species.
This statement can be placed into the context of what others have claimed about natural selection compared to ecological speciation July 2013 Carl Zimmer: “Others maintain that as random mutations arise, complexity emerges as a side effect, even without natural selection to help it along. Complexity, they say, is not purely the result of millions of years of fine-tuning through natural selection—the process that Richard Dawkins famously dubbed “the blind watchmaker.” To some extent, it just happens.”June 2013 James Kohl “…the model represented here is consistent with what is known about the epigenetic effects of ecologically important nutrients and pheromones on the adaptively evolved behavior of species from microbes to man. Minimally, this model can be compared to any other factual representations of epigenesis and epistasis for determination of the best scientific ‘fit’.”
Re: “…compared to any other factual representations of epigenesis and epistasis…”
“…genomic conservation and constraint-breaking mutation is the ultimate source of all biological innovations and the enormous amount of biodiversity in this world. In this view of evolution there is no need of considering teleological elements” (p. 199).
See for comparison: Understanding faith, teaching evolution not mutually exclusive
My comment: “In… the New York Times (3/8, MM60, Zimmer, …) reports on the developing view among scientists about the status of “junk” DNA, also known as non-coding DNA. Though previously it was thought to be nonessential, in January, Dr. Francis Collins… made a comment that revealed just how far the consensus has moved.” Asked about junk DNA at a healthcare conference Collins said, “We don’t use that term anymore. It was pretty much a case of hubris to imagine that we could dispense with any part of the genome — as if we knew enough to say it wasn’t functional.” He added that “most of the DNA that scientists once thought was just taking up space in the genome…’turns out to be doing stuff.'” The Times notes that some biologists reject this hypothesis.”
See also: Is Most of Our DNA Garbage?
Scientists estimate that the first eukaryotes evolved about 2 billion years ago, in one of the greatest transitions in the history of life. But there is little evidence of this momentous event, no missing link…
My comment: Some of the uninformed biologists are interviewed by Zimmer.
This is a genuine breakthrough,” said Eugene Koonin, an evolutionary biologist at the National Center for Biotechnology Information who was not involved in the research. “It’s almost too good to be true.”
“The entire evolution of the microbial world and the virus world, and the interaction between microbes and viruses and other life forms have been left out of the Modern Synthesis…” — Eugene Koonin
My comment: The question arises: Can anything taught to today’s students about evolution be useful without ridiculous ideas about mutations and natural selection?
This was reported as: Evolutionary Rewiring
The “re-evolution” of the bacterial flagellum in 4 days makes sense if it was driven by viruses. It does not make sense to put it into the context of evolution either with or without mutations and natural selection.
See my additional comments to The Scientist.