Replies

Evolution is far from sacrosanct. Since Darwin’s formulation of it, there have been several significant revisions of important aspects of it:

· Mendelian heredity: Darwin thought genes were both blending (not particulate) and influenced by the environment of the organism, a kind of Lamarckian inheritance he called “pangenesis.”

· Speciation: For a long while Darwin’s own view on what caused new species to rise (natural selection) was rejected by most biologists in favor of geographical isolation. Only recently has Darwin’s view come back into favor as one cause among many.

· Jumping genes: Barbara McClintock won the Nobel Prize for showing that genes can move from one place to another within the genome.

· Symbiotic origins of organelles: Lynn Margulis proposed that the ancestors of eukaryotic cells arose from prokaryote cells joined together in “symbiotic consortiums” (Margulis 1981).

· Genetic drift: This idea from Sewall Wright says that much genetic change in populations is due to random drift rather than natural selection.

· Neutral theory, proposing that most generic variation is neutral, not subject to selection (or nearly neutral, in Ohta’s extension of the theory; Kimura 1983; Ohta 1992).

· Prions: The discovery of an entirely new kind of “life” form that replicates without genetic material via a catalytic change of molecular configuration. This also yielded a Nobel Prize for Stanley B. Prusiner.

· Lateral gene transfer: Some genetic material is not inherited from an immediate ancestor but from distantly related organisms (e.g., Woese 2000).

Challenges to parts of evolutionary theory continue today. However, they are the sort of thing one rarely encounters below the graduate level.

Evolution has undergone a tremendous amount of testing, some of which has shown that correction is necessary. Correcting a scientific theory makes the (corrected) theory stronger. The testing and correction account for evolution’s strong reputation today

http://www.talkorigins.org/indexcc/CA/CA611.html