From: Terry M. Gray (grayt@lamar.colostate.edu)
Date: Tue Aug 12 2003 - 12:45:15 EDT
Just to add a bit to David's comments here:
Modern molecular biology, molecular genetics, and genomics has
discovered a number of genetic alterations that appear to have been
important in macroevolutionary events: mobile genetic elements, gene
duplications, incorporation of reverse transcription DNA, chromosomal
rearrangements, chromosomal duplications, horizontal gene transfers,
acquistion of genomes via endosymbiotic events, etc. In some ways
these are forms of mutations (albeit obviously not single base
changes as typically conceived) that introduce variation into a
population. Natural selection (and other factors along the lines of
what David listed) operates on these variations as well.
Many of these things are NOT part of the classical neo-Darwinian
explanation--although I don't think it takes too much to bring them
into the fold.
TG
> >Can you just recite one or more _scientific_ alternatives to
>natural selection.<
>
>Other factors that are believed to influence evolution, besides
>natural selection, include genetic drift (the effects of random
>genetic envents), catastrophic selection (e.g., asteroid impact),
>sexual selection, physical constraints, historical factors (e.g.,
>who got there first), genetic linkages (e.g., strong jaws and weak
>backs in bulldogs and pandas), and exaptation (the use of something
>that initially evolved for another purpose). The relative role of
>each of these, along with natural selection, is debated; it
>certainly varies a good deal between situations.
>
>The metaphysical misrepresentation of Darwin is not due entirely to
>Christian circles. Ruse puts much of the blame on Huxley, despite
>being philosophically sympathetic to Huxley's agenda.
>
> Dr. David Campbell
> Old Seashells
> University of Alabama
> Biodiversity & Systematics
> Dept. Biological Sciences
> Box 870345
> Tuscaloosa, AL 35487-0345 USA
> bivalve@mail.davidson.alumlink.com
>
>That is Uncle Joe, taken in the masonic regalia of a Grand Exalted
>Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at
>Droitgate Spa
>
-- _________________ Terry M. Gray, Ph.D., Computer Support Scientist Chemistry Department, Colorado State University Fort Collins, Colorado 80523 grayt@lamar.colostate.edu http://www.chm.colostate.edu/~grayt/ phone: 970-491-7003 fax: 970-491-1801
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