The Fact of Evolution 1) Evolutionary processes have been seen and sometimes manipulated in animal breeding, bacteria, viruses, fishes, spiders, flies, birds, and mosquitos. 2) There are sequences of skulls, teeth, and femurs scattered over the globe. The estimated times and geographical dispersion of bones correlate strongly with those of blood types and linguistic groups (Cavalli-Sforza, 2000). 3) Relics exist in all of us from our prior body plans. For example, whales have rudimentary limbs complete with wrists and fingers, snakes have unformed pelvises. 4) Embryology tells us about similarities in body plans from conception to a phylotypic stage to the adult. Much of evolution can be seen as variation in the timing and relative magnification of the different components of one basic plan (Raff, 1996). 5) Human genes commonly have homologs in other species that include flies, mice, and even yeast. It is more surprising not to find a homolog. 6) Interfere with Pax-6, the poster child of genetics, in fruit flies and their eyes will fail to develop. Replace fly Pax-6 with one from a squid or mouse and the fly develops normal eyes. Insert Pax-6 onto a wing, leg, or thorax and an eye, complete with retina and active electroretinogram develops at that site (although there are no connections to the CNS). Evolution does not imply progress. Evolution may also be reflected in the adaptability of a group to varied environments. Example: there are more species of beetles and perhaps ants than we can count. Roaches were probably here before us and will be here after our next great war. Notes & Refs See Zimmer, C. (2001) Evolution: The Triumph of an Idea. NY: Harper Collins, chapt. 4. Copyright 2002, James Brody, All rights reserved.
Cavalli-Sforza, Luigi L. (2000) Genes, Peoples, and Languages. NY: North Point Press. Cavalli-Sforza, Luigi L. and Cavalli-Sforza, F. (1995) The Great Human Diasporas: The History of Diversity and Evolution. Reading, MA: Addison Wesley.
Raff, Rudolf (1996) The Shape of Life. Chicago, IL: University of Chicago Press.
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