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Mechanisms of Comological & Biological Evolution



Dear Colleagues,

A few years ago while working on a white paper, I helped prepare a one sheet
overview of the mechanisms of evolution. Whenever I run into debates
regarding evolution I like to ask the detractors to specify exactly which
of the mechanisms are actually being debated. As most of you are aware,
Contrary to recent comments, evolutionary theory isn't "set" or
"standardized". The details of many of the mechanisms are hotly debated
(especially at the speciation level).

The overview, appended below, has helped me ground more than one debate on
issues that can be discussed with at least some regard to scientific
evidence. In truth, most of the time it simply drives away
scripture-quoting pseudoscientists who don't "believe" (belief is an
inappropriate word, i.e., I don't "believe" in evolutionary theory --
scientists accept or reject the argument regarding evolutionary theory) in
evolution but know little about the actual mechanisms at issue and are thus
unable to debate the actual mechanisms of the theory they so despise.

I hope it may be of some help to those teachers who are called on from time
to time to defend evolutionary theory, especially those teaching the
physical sciences who may not have the time to become acquainted with all
the complexities of biological science..

Does anyone have something similar for cosmology?

Best Regards,
K.

A brand new, cleaning the lab, putting up my Periodic Table, Standard Model
& Correlated History of the Earth posters, filled with trepidation,
untenured, heading toward the sunset of life, AP Physics, Chemistry &
Biology teacher.

P.S. You know, at the university level I never felt queasy. Although I
realize that many will not major in science, it helps a bit that almost all
of the AP students will go on to college. What makes me a tad nervous is
that a substantial number of youngsters are going to be looking at me over a
period of three years to explain the Universe to them. For many, whatever I
relate to them regarding the beautiful complexities of the Universe is all
the formal exposure they are ever going to get. Suddenly, I feel very
inadequate to that task!

Drizzle, Drazzle, Drizzle , drom ...

____________________________________________________________________________
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Overview of the Mechanism of Evolution.

Evolution, in biology, is the process of biological change over time.
Evolution occurs through a complex of interrelated processes.
Evolution explains the change in any given gene pool of a population over
time.
Evolutionary change can be beneficial, neutral or deleterious.
Evolutionary theory does not support Social Darwinism or prove false other
cosmological concepts.

Fundamental definitions and concepts.
A gene is a hereditary unit in the synganmeon.
The gene pool is the set of all genes in a species or population.
Evolution requires genetic variation.
There are no extant primitive organisms.

Mechanisms of Evolution
Mechanisms than increase genetic variation:

1) Mutation
Chromosomal Mutations
Translocations
Inversions
Deletions
Chromosome non-disjucntion
Point Mutations
nonsense mutation
missense mutation
silent mutation
Frame shifts
Impairment of DNA repair mechanisms

2) Recombination
Linkage disequilibrium

3) Gene Flow

Mechanisms that decrease genetic variation:

4) Genetic Drift

5) Natural Selection -- the differential reproductive success of
differing genotypes. Fitness is the success of an entity in reproducing
(i.e., contributing alleles to the next generation). Natural selection is
not Strum und Drang “Storm and Turmoil” the “struggle” is metaphysical.
Darwinism is not survival of the fittest but only of the “tolerably fit”.

Directional (extreme phenotype is favored)
Stabilizing (normalizing -- intermediate phenotype is
fittest)
Disruptive (diversifying -- 2 extreme phenotypes fitter than
intermediate)