PPT-Natural Selection The Theory of Evolution

Evolutionary Ideas A lthough Darwin is given much credit for evolutionary theory he was not the first person to come up with the idea Evolution is the change in a population over time The concept of evolution had been discussed for more than 100 years prior to Darwins theory. 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. Evolution- changes in the characteristics of groups of organisms over time . Charles Darwin was the first to propose a feasible . mechanism. for evolution. It is called . natural selection. . . Evolution by Natural Selection is a theory. . Why the -ism?. The –ism indicates a “belief”. Why the -ism?. By the end of this unit,. I hope to show you, . - There is no logical basis for believing in Evolution. - That . Evolution is nothing more than a . Testable Hypotheses. Use if…then… logic. Collect data . Reject the null hypothesis. Support the hypothesis. Devise another test, and another, and another!. Darwinian Theory. Evolutionary change is inevitable if:. A mechanism for change in populations.. Any change in the . inherited . traits within a population across generations. Individuals better adapted to their environment tend to survive and . produce more offspring. Danielle Donahue. Aa. A. daptation: a well fitted feature that aids in the survival of a population. Example: the blind cave salamander has no use for eyes because they live in complete darkness. Bb. What is natural selection?. It’s the . process whereby organisms better adapted to their environment tend to survive and produce more offspring. . The . theory. of its action was first fully . explained . Modern Theory of Evolution) . Review Questions. What structure does this picture represent?. Answer: Homologous Traits . What is an adaptation?. A) . A test for natural selection . B) . A. . physical or behavioral characteristic that has developed to allow an organism to better survive in its environment. Chapter 8B. History of Evolutionary Theory. I. History of Evolutionary Theory. Definitions. 1. Evolution. Evolution. The gradual change that causes something to improve or become more complex. Ex.) The . Gibson. Geoscience Research Institute. www.grisda.org. Summary. Evolution is the theory that all organisms have descended from a common ancestor by unguided (natural) processes.. The Cambrian Explosion contradicts the pattern . wallace. and was explained in book “ on the origin of species by means of Natural Selection . . Darwin put the theory based on his observations as he travelled round the world on the ship Beagle.. What is a scientific theory?. In science, the word theory applies to a well-tested explanation that unifies a broad range of observations and hypotheses and that enables scientists to make accurate predictions about new situations.. and Variation . What is Evolution?. Simply… a change in living organisms over time. Why study evolution?. Evolutionary concepts provide a solid foundation to much of modern biology. - . you can’t fully understand current trends in biology or you will have difficulty understanding evolution. Diversity and Evolution Of Living Organisms . The scientific theory of evolution is the . organizing . principle. of life science.. 2. The scientific . theory of . evolution is supported . by . multiple forms.