2/1/2011 The 2 fundamental questions: y Has evolution taken pp,lace, and if so, what is the Section 4 evidence? Professor Donald McFarlane y If evolution has taken place, what is the mechanism by which it works? Lecture 2 Evolutionary Ideas Evidence for evolution before Darwin Golden Age of Exploration y Magellan’s voyage –1519 y John Ray –University of y Antonius von Leeuwenhoek ‐ microbes –1683 Cambridge (England) y “Catalog of Cambridge Plants” – 1660 –lists 626 species y 1686 –John Ray listing thousands of plant species! y In 1678, Francis Willoughby publishes “Ornithology” Linneaus and Kirchner Athenasius Kircher ~ 1675 –Noah’s ark Carl Linneaus – Sistema Naturae ‐ 1735 Ark too small!! Uses a ‘phenetic” classification – implies a phylogenetic relationship! 300 x 50 x 30 cubits ~ 135 x 20 x 13 m 1 2/1/2011 y Georges Cuvier 1769‐ 1832 y “Fixity of Species” Evidence for Evolution –prior to 1830 • Enormous diversity of life –WHY ??? JBS Haldane " The Creator, if He exists, has "an inordinate fondness for beetles" ". Evidence for Evolution –prior to 1830 Evidence for Evolution –prior to 1830 y The discovery of variation. y Comparative Anatomy. Pentadactyl limbs Evidence for Evolution –prior to Evidence for Evolution –prior to 1830 1830 y Fossils – homologies with living species y Vestigal structures Pentadactyl limbs !! 2 2/1/2011 Evidence for Evolution –prior to 1830 Evidence for Evolution –prior to 1830 y Invariance of the fossil sequence y Plant and animal breeding JBS Haldane: “I will give up my belief in evolution if someone finds a fossil rabbit in the Precambrian.” Charles Darwin Jean Baptiste Lamark y 1744‐1829 y 1809 –1882 y Organisms have the ability to adapt to their y Voyage of Beagle 1831 ‐ 1836 environments over the course of their lives. y Organisms have the ability to pass on these ‘acquired characteristics’ to their offspring. y Organisms have a built‐in “drive to perfection” Alfred Russel Wallace y 1858 –The Linnaean Society y 1823 –1913 y Wallace’s Ternate paper + y Amazon 1848 ‐1852 y Darwin’s letter to Asa Gray y “Wallacea” 1854 ‐ 1862 y 1859 –“Origin of Species” 3 2/1/2011 The 5 tenets of the Theory of Natural The Modern Synthesis Selection y Early to mid‐20th Century y All organisms show variation y RA Fisher ~ 1918 ‐ statistics y At least some variation is heritable y JBS Haldane ~ 1924 –evolutionary genetics y All organisms produce more offspring than y Sewall Wright –evolutionary genetics can survive y George Gaylord Simpson – paleontology y Offspring with ‘favorable’ variations will have a better chance of survival and y Ernst Mayer –biogeography and speciation reproduction y The ‘favorable’ variation will be more common in the next generation 4.