BIOL 152 1st Edition Lecture 1 Outline of Current Lecture I Darwinian revolution challenged traditional views of Creationism II Darwin proposes ideas of evolution through Natural Selection Current Lecture Descent With Modification Key Terms Natural Selection differential success in reproduction of different phenotypes resulting from interaction of organisms with their environment Evolutionary Adaptation accumulation of inherited characteristics that enhance organism s ability to survive long enough to reproduce Evolution change over time in genetic composition of a population I Darwinian revolution challenged traditional views of Creationism A Resistance to Idea of Evolution 1 Aristotle viewed species as fixed and unchanging agrees with Bible 2 Linnaeus classified life developed binomial taxonomic system a did not see physical similarities as evolutionary relationship but as pattern of design by Creation 3 Cuvier developed Paleontology noticed species disappearing and appearing in strata a believed in catastrophism that populations of species were wiped out suddenly due to flood fire etc and new species appearing in strata were species who came from elsewhere B Theories of Gradualism 1 Gradualism idea that profound change can take place through cumulative effect of slow but continuous processes 2 Uniformitarianism idea that same geologic processes that formed Earth are still working today and at same rate 3 Lamark s Theory of Evolution a believed that individuals could pass acquired traits b wrong II In Origin of Species Darwin proposed that species change through Natural Selection A Two main ideas 1 Evolution explain life s unity and diversity 2 Natural Selection is a cause of adaptive evolution B Organisms with traits favored by environment tend to survive longer and produce more offspring C 3 points 1 Individuals do not evolve populations do 2 Natural Selection can only amplify or diminish heritable traits can not create new traits 3 Environmental factors vary from place to place and time to time what is a favorable trait at one location at one point may not be good elsewhere may even be detrimental D Homology 1 Homology similarity in physical traits but with different functions 2 View of evolution as a remodeling process accounts for findings of comparative anatomy 3 Homologous structures structures that are composed similarly but have different functions ex Cat paw and whale flipper with five digits and wrist bones 4 Because evolution can only modify not create results are less than perfect 5 Genetic code is shared by all living species likely we all have a common ancestor E Biogeography geographic distributions of species 1 Plays big role in evolutionary theory where animals are located will decide how animals live ex Fins for aquatic animals thicker fur for mammals in colder areas 2 Endemic found nowhere else in the world F According to fossil record prokaryotes are oldest known life