Neo-Darwinism

by Max Andrews

Evolution has many meanings.

  • Change over time
    • Evolution of the cosmos
    • Evolution of living things
    • Evolution of culture, technology, etc.
  • Changes within existing species
    • Morphological (anatomical)
    • Genetic (change in gene frequencies)
  • Common ancestry
    • Within a species
    • Descent of all species from a common ancestor
  • Darwinian evolution

Darwinism: Descent with modification through unguided processes

  • Descent:  “I view all beings not as special creations, but as the lineal descendants of some few beings which lived long ago.”
  • Modification:  “The preservation of favorable individual differences of variations, and the destruction of those which are injurious (natural selection).”
  • Unguided processes:  “There seems to be no more design in the variability of organic beings, and in the action of natural selection, than in the course which the wind blows. So I am inclined to look at everything as resulting from designed laws, with the details, whether good or bad, left to the working out of chance.”

Neo-Darwinism:  Descent with modification through unguided processes plus genetics

  • Darwin thought that traits are blended together in heredity (“pangenesis”), but Gregor Mendel showed that traits are inherited as discrete factors
  • In 1930’s, Darwinists adopted Mendelean genetics into modern synthesis
    • All living things are descended from one or a few common ancestors
    • All features of living things are due to unguided natural processes such as random variation and natural selection
    • Genes (DNA) carry all essential hereditary information and control embryo development
    • Mutations in DNA are the source of the new variations that provide the raw materials for evolution
    • Although living things may appear to be designed, the design is just an illusion.

Evidence of natural selection and mutation

  • Peppered moth
    • Observation
      • Two hundred years ago, most moths were light-colored.  During the industrial revolution, dark moths became much more common
    • Theory
      • Dark moths became more common because they were better camouflaged on soot-darkened tree trunks, and birds preyed selectively on light moths.
    • Experiment
      • In the 1950’s, Bernard Kettlewell released moths onto nearby tree trunks and watched as birds ate the less camouflaged ones
    • Conclusion:
      • Kettlewell found Darwin’s evidence for natural selection
    • In 1980’s and 1990’s biologists discovered that peppered moths don’t normally rest on tree trunks in the wild.  Most of the textbook photos had been staged.
    • In any case, this famous story illustrates only a shift in the proportions of light and dark-colored moths, a shift that was later reversed.  No new species originated.
  • Galapagos finches
    • In 1977, a severe drought killed about 85% of the medium ground finch because only the large beaked finches could eat the hard dried up seeds
    • But when the drought ended and food again became plentiful, average beak size returned to normal.  No net evolution occurred.
  • Anti-biotic resistance in bacteria
    • Resistance makes the organism more fit only in the presence of the antibiotic.
    • Resistance is only biochemical; no new structures form.
    • Selection does not produce new species.
      • “Throughout 150 years of the science of bacteriology, there is not evidence that one species of bacteria has changed into  another… since there is no evidence for species changes between the simplest forms of unicellular life, it is not surprising that there is no evidence for evolution… throughout the whole array of high multicelluar organisms.” Alan Linton (2001)
  • Genetic mutations
    • Mutations with significant effects on anatomy invariable produce organisms that are less fit.
    • There is no evidence that genetic mutations can provide the sort of beneficial anatomical changes that could provide raw materials for major evolutionary changes.
    • We can mutate a fruit fly embryo as much as we like, and there are only three possible outcomes:
      • A normal fruit fly
      • A defective fruit fly
      • A dead fruit fly
  • Summary
    • The evidence does not support the Neo-Darwinian claim that mutations and selection account for the origin of new species, organs, and body plans.

Evidence for descent from a common ancestor

  • Fossils
    • Most major phyla (7) of animals appear at about the same time, fully formed, with no fossil evidence of common ancestry
    • Instead of a bottom to top tree there is a top to bottom
    • If you were to dig up two recenthuman skeletons, you could not tell—without written records and identifying marks (or in some cases DNA)—how they were related to each other.
      • If we cannot tell how two recent skeletons form the same species are related to each other, we certainly cannot tell the relation between two unrelated species.
      • Darwinists assume.
      • “To take a line of fossils and claim that they represent a lineage is not a scientific hypothesis that can be tested, but an assertion that carries the same validity as a bedtime story—amusing, perhaps, even instructive, but not scientific.”  Henry Gee
  • Embryos
    • (Evaluation of Haeckel’s embryos)
  • Molecules
    • “The evidence for evolution from molecular biology is overwhelming and is growing quickly.” (NAS, 1999)
    • The many inconsistencies show that molecular evolutionary trees cannot provide evidence for common ancestry.  In fact, common ancestry must be assumed in order to construct such phylogenetic trees.
  • Homology
    • There are similarities in structure and position, but not function (similarities)
    • There are similarities in function, but not structure (analogies)
      • “Why should similar bones have been created to form the wing and the leg of a bat, used as they are for such totally different purposes, namely flying and walking.” Darwin
    • Does homologous fossil sequence really provide evidence for natural selection?
      • A series of homologies do not say whether something has been designed or a product of natural selection (i.e. Tim Berra’s Corvettes)
    • Darwinists have tried to redefine homology, “Similarities are due to common ancestry.” (begging the question)
    • Without knowing the mechanism, homology provides no more evidence for natural selection than for design

One Comment to “Neo-Darwinism”

  1. Thanks for your thoughtful study and sharing.

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