Re: News: New Nucleotide In DNA Could Revolutionize Epigenetics,Organization
- From: John Edser <edser@xxxxxxxxxxxxxx>
- Date: Mon, 20 Apr 2009 13:56:24 -0400 (EDT)
sci.bio.evolution moderation account wrote:
"The results are discrete and crystalline and clear; there is no
uncertainty. I think this finding will electrify the field of
epigenetics."
Genes alone cannot explain the vast differences in complexity among
worms, mice, monkeys and humans, all of which have roughly the same
amount of genetic material. Scientists have found that these
differences arise in part from the dynamic regulation of gene
expression rather than the genes themselves. Epigenetics, a
relatively young and very hot field in biology, is the study of
nongenetic factors that manage this regulation.
JE:-
Before epigenetic (above the gene) factors can be meaningfully discussed
missing genetic factors have to be re-included within any synthetic
evolutionary theory. At the gene level the genetic factors which
empirically manage regulation are represented by non additive genetic
epistasis. This was and remains deleted from Neo Darwinistic models e.g.
Hamilton's inclusive fitness which continues to form the basis of
today's poly-centric (many levels of selection) Neo Darwinism. This Neo
Darwinistic synthesis deleted all genetic epistasis from
mono-centric (only one level of selection remains proposed) Darwinism
including the most critical non additive trait of them all: _gene
fitness genetic epistasis_. IOW, Neo Darwinism was and remains an
uncorrected oversimplification of Darwinism. Fisher and Haldane's
enormous deletion allowed a modeling gene fitness independence which
simply did not exist within nature. In turn their model has allowed
Hamilton and subsequently Dawkins' popular "selfish gene" concept which
continues to dominate evolutionary theory within popular "Sociobiology".
I contend that genetic epistasis is represented by the more complex non
additive logic of nested sets. These must be contrasted to the more
simple, additive logic of intersecting sets as they can found within any
population. Any organism presents a single, non reversible nested set of
body part fitnesses whereas any population presents reversible,
intersecting sets of fitnesses only allowing adult (fertile) individuals
to be naturally selected and populations of same to evolve. The reverse
of this i.e., individuals evolving (gene centric selection) and
populations being selected (group selection) remains 100% prohibited
within Darwinism as a falsification of that theory. OTOH these
observations are not prohibited within Neo Darwinism which unlike
Darwinism, cannot provide a single falsification only a non
verification. A falsification is not a non verification. The fitness of
each genomic gene remains locked up within the fitness of each fertile
form as an entirely nested fitness even if genes can independently
segregate at meiosis, i.e. gene fitnesses never were independent of the
single body fitness each gene finds itself within. Neo Darwinians still
have to confront and not simply evade the empirical fact that epistatic
traits can be heritable. Only after this fact becomes accepted can
epigenetic traits be meaningfully incorporated within evolutionary theory.
One key epigenetic player is DNA methylation, which targets sites
where cytosine precedes guanine in the DNA code. An enzyme called DNA
methyltransferase affixes a methyl group to cytosine, creating a
different but stable nucleotide called 5-methylcytosine. This
modification in the promoter region of a gene results in gene
silencing.
JE:-
DNA methylation represents a nested set which contains all of the
genetic regulators in one body. While genomic genes remain set nested,
i.e. provide an unequal and entirely non reversible hierarchy of
regulation, in turn all genes remain nested within DNA methylation as an
epigenetic mechanism per body. Each nested set can be presented as a
concentric circle only leaving ONE circle that can nest all of the
others, i.e. regulates all of the others within a body. This I contend
ON A FALSIFIABLE BASIS is total Darwinian fitness (TDF) defined as the
total number of fertile forms reproduced per parent per population. I
propose that TDF represents a Darwinian fitness maximand.
snip the fascinating details of DNA methylation<
Regards,
John Edser
Independent Researcher
edser@xxxxxxxxxxxxxx
.
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