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Modern Evolutionary Theory

Modern Evolutionary Theory. What happened after darwin ?. Problems with darwin’s theory. Why is there variation within a species? How are traits passed from one generation to another?.

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Modern Evolutionary Theory

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  1. Modern Evolutionary Theory What happened after darwin?

  2. Problems with darwin’s theory • Why is there variation within a species? • How are traits passed from one generation to another? http://4.bp.blogspot.com/-EmedhzGoq4U/Tl14PpYybRI/AAAAAAAAgT0/nzHhIdibNw8/s800/101%2Bdalmatians%2Bposter.jpg

  3. Watson and crick’s model of dna structure • genes– portions of the DNA that code for a specific protein • proteins– amino acid sequences that are workhorses of living systems Central Dogma of Molecular Biology DNA  RNA  protein http://www.chemheritage.org/Images/Main-Images-250x290/Discover/Themes/Biomolecules/watson-crick1.jpg

  4. Discovery of the genetic code • series of instructions that shows how proteins are made based on DNA/RNA http://4.bp.blogspot.com/-v3WGNk-6Pps/TxgT9DFFntI/AAAAAAAAGgA/U2ZMO0-Qzjc/s1600/Dna%2Bgenetic%2Bcode%2BUnseen%2BRare.jpg

  5. Sources of inheritable variation • Mutation • any change in DNA sequence • due to • mistakes in DNA replication • environmental factors http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/MUT/Mut.Mutation.html, http://static.ddmcdn.com/gif/evolution-fly.gif

  6. Sources of inheritable variation • 2. Gene shuffling • independent chromosome movement during gamete formation(223~8.4 million gene combinations) • sexual reproduction causes variation within populations • members of a population interbreed and are acted on in similar ways by the environment; they evolve together http://1.bp.blogspot.com/_bAYLalavZ6w/TPtJ5s9xlZI/AAAAAAAAAD0/6KPTjLGRM8g/s1600/meiosis.gif, http://local.brookings.k12.sd.us/biology/Mitosis.htm

  7. http://www.brainbeau.com/cihs/Evolution/Genes_Variation_Genetic_Change_files/slide0066_image020.jpghttp://www.brainbeau.com/cihs/Evolution/Genes_Variation_Genetic_Change_files/slide0066_image020.jpg Evolution as genetic change

  8. Evolution as genetic change http://www.citruscollege.edu/lc/archive/biology/PublishingImages/0306l.jpg

  9. Evolution as genetic change • Natural selection is NOT always necessary for genetic change to occur • Genetic drift • when an allele becomes common in a population by chance • not all characteristics of an organism contribute to its fitness http://biology.unm.edu/ccouncil/Biology_203/Images/PopGen/bottleneck.gif

  10. SpeciationFormation of a new species • species group of organisms that interbreed and produce fertile offspring • reproductive isolation • behavioralisolation • geographic isolation • temporal isolation

  11. http://csmith1974.files.wordpress.com/2010/11/behavioral-isolation-1.jpg, http://bioweb.cs.earlham.edu/9-12/formation/IMAGES/fish.jpg, http://biology-forums.com/gallery/33_14_07_11_5_59_19.jpeg

  12. Experimental evolution • Darwin’s Hypothesis http://4.bp.blogspot.com/-KhUhy5HCFNk/TVb-KjAZtGI/AAAAAAAAAew/f4iTxy9qSE4/s1600/Galapagos-finches.jpg

  13. Experimental evolution • Grant Experiment

  14. Speciation in darwin’s finches

  15. MacroevolutionLarge-scale evolutionary changes that occur over long periods of time

  16. http://mindblowingscience.com/science-by-numbers/the-5-major-mass-extinction-events/http://mindblowingscience.com/science-by-numbers/the-5-major-mass-extinction-events/

  17. MacroevolutionLarge-scale evolutionary changes that occur over long periods of time http://students.washington.edu/kjbyers/coursework.html

  18. MacroevolutionLarge-scale evolutionary changes that occur over long periods of time

  19. http://withfriendship.com/images/i/42351/Punctuated-equilibrium-picture.jpg, http://sciphu.files.wordpress.com/2008/02/punctuated-equilibrium.jpg

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