PPT-Lesson # 7: Evolution

Processes Patterns of Evolution Evolutionary Change via Selection Types of selective pressures may result from ie climate conditions food availability predators and choice of mate etc. Scientific Theory. Social use of the word “theory”. Not the same as in science. Implies a hunch or a casual guess. Scientific Theory. 1. Highly probable explanation based on vast collections of scientific data. The . formation of a new . species. 15.3 Speciation. What is a species?. A group of organisms with similar characteristics capable of producing fertile . offspring. Members of a . species. . share. the . The Importance of Evolution in Ecology. Ecologists study proximate or “how” questions:. How nutrients flow through ecosystems. Evolutionary biologists study ultimate or “why” questions:. Why does a stickleback fish have armor in one lake but not another?. Chapter 10. Biological Evolution. Evolution the word, has several meanings. Evolution – gradual change to improve or become more complex - change. Evolution – random changes made by chance to get what we see today – goo to you (theory of evolution). Which one?. There are 3 great universal questions. 1) Where did I come from?. 2) Why am I here?. 3) Where am I going?. The answer to the last 2 questions are dependent upon the answer to the first question. . Organism DNA. 1a. Some of the strongest evidence for evolutionary relationships comes from studying the DNA of different organisms.. 1b. The fact that all organisms use the same DNA molecule to code for genetic information suggests that these organisms share a distant ancestor.. LAMARCK (1744 – 1829) . He proposed . 3 theories. to explain how species change…. Theory of Need. Theory of Use and Disuse. The Theory that Acquired Traits Can Be Passed on to Offspring.. August Weismann (1834-1914). What do we use in order to determine evolutionary relationships?. Fossil Record. Anatomical Evidence. Molecular Evidence. Embryological Evidence. Evidence for Evolution. Fossil Record. Evidence for Evolution. Mechanisms of concerted evolution. Unequal cross-over. Gene conversion: non-reciprocal transfer of information between homologous sequences; the main mechanism invoked to explain concerted evolution. Tricia Radojcic, Ph.D.. Chaparral High School, Murrieta, California . and. Theodore Garland, Jr., Ph.D.. University of California, Riverside. Supported by National Science Foundation,. American Physiological Society,. Chapter 17: Processes of Evolution. Early Beliefs. 19. th. century: discovered species shared many traits, but lived in different parts of the world. Problematic – species only looked similar on the outside, but inside were very different . Science. Comparison with blood chemical (‘B’) between humans and other vertebrates.. humans. -. chimpanzee. 0. chicken. 11. Rhesus monkey. 1. frog. 17. mouse. 8. lamprey. 29. Challenge answer. What organisms are most closely related to us? . . The process by which organism change over time. Based on science, not opinion.. Darwin. :. Evolution is descent with modification. Evolution. :. changes through time. Species accumulate difference. . The process by which organism change over time. Based on science, not opinion.. Darwin. :. Evolution is descent with modification. Evolution. :. changes through time. Species accumulate difference.