PowerPoint PresentationThe Evidence for EvolutionSlide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28The Evidence for EvolutionI. Evidence exists for change in the earthA. Geology1. fossils are found in layers-Different layers contain different types of fossils- Azoic layers are always deeper than zoic layers. 2. radiometric dating indicates that the earth is very old (over 4 billion years old)Stratigraphy3. Principle of superposition4. Principle of cross-cutting relationships5. Principle of faunal successionLocation of fossils allows reconstruction of phylogeny and time sinceB. Phylogenies reconstruct evolutionary historyA BDECOrigin of male size polymorphism in poeciliid fishesAnd allow us to understand the origin of key innovationsOrigin of melanocortin 4 receptor mutationsPresence of “fatboy” alleles(B1/B2 Lampert et al. 2010)C. Hypotheses to explain earth’s change1. Catastrophism--Cuvier 1769 - 1832-series of floods and successive sedimentation accounts for different layers or strata-explained how new creatures came about-each successive fossil layer represents separate creations by God-such catastrophes have not been observed in historic times2. Uniformitarianism--Hutton 1788; Lyell 1830-more correct view point-geological processes now are same as in the past-geological processes are gradual-implies that the earth is very oldThus processes operating today can account, by extrapolation over long time periods, for the evolution of the earth and of life.D. How old is the earth?1. Radiometric datingP -parent compoundD - daughter compound2. Geologic Time ScaleOrder by Hutton andLyell--ages added laterthrough radiometricdatingThe Evidence for EvolutionII. Evidence from the Fossil RecordA. The Fact of Extinction1. Cuvier-1812-Description of fossilextinct Irish Elk-Extinct speciesare relatives of livingspecies found todayB. The Law of Succession1. Close relationship between fossil and extant species from the same geographic area2. Close relationship between fossil forms in adjacent rock strataFossil glyptodontPygmy armadillo (Zaedyus pichiy)C. Transitional forms1. Contain characteristics of ancestral species as well as novel traits of the descendants. Example: Tiktaalik NovelAncestralTiktaalik roseaeLate Devonian 370 MYADaeschler et al. Nature 2006Tiktaalik roseaeLate Devonian 370 MYADaeschler et al. Nature 2006The Evidence for EvolutionIII. Evidence of common ancestryA. Homology suggests common ancestryQuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.1. Analogous structures have a common function but not an embryotic origin. 2. Homologous structures have a common embryonic origin but may or may not have a common functionHomologyAnalogy3. Homologies that are not analogies provide the strongest support for common ancestry-Homologous bones in vertebrate forelimbs4. Genetic homology-Genetic code is nearly universalHomeodomain region in protein important to eye developmentB. Evolutionary change can create new species1. artificial selection has resulted in new crop varieties and animal breeds2. In a similar manner, natural selection has created new