Chapter 22 - Chapter 22: Descent with Modification (A...

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Chapter 22: Descent with Modification (A Darwinian View of Life) Adaptations : inherited characteristic of an organism that enhances its survival and reproduction in specific environments Artificial Selection : selective breeding of domesticated plants & animals to encourage the occurrence of desirable traits Biogeography Catastrophism : principle that events in the past occurred suddenly & were caused by different mechanisms than those operating today; eg. floods Continental Drift : slow movement of the continental plates across Earth’s surface Convergent Evolution : evolution of similar features in independent evolutionary lineages Endemic : referring to a species that is confined to a specific, relatively small geographic area Evolution : descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in the genetic composition of a population from generation to generation Evolutionary Tree : branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms Fossils : preserved remnant or impression of an organism that lived in the past Homologous Structures : structures in different species that are similar because of common ancestry Homology : similarity in characteristics resulting from a shared ancestry Natural Selection : process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics Paleontology : scientific study of fossils Pangaea : supercontinent that formed near the end of the Paleozoic era, when plate movements brought all the land masses of Earth together Strata : rock layer formed when new layers of sediment cover older ones and compress them Uniformitarianism : principle stating that mechanisms of change are constant over time Vestigial Structure : structure of marginal, if any, importance to an organism. Vestigial structures are historical remnants of structures that had important functions in ancestors
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Chapter 22: Descent with Modification (A Darwinian View of Life) 1. Overview: Endless Forms Most Beautiful 1. Pattern of evolution change- revealed by data (facts/observations) from scientific disciplines 2. Process of evolution consist of mechanisms that produce observed pattern of change 2. 22.1: Darwinian revolution challenged traditional views of young Earth inhabited by unchanging species 1. Scala Naturae 1. Aristotle(384-322 BC) viewed species as fixed (unchanging); concluded life-forms be arranged on ladder/scale of increasing complexity ; greatly influenced early Western science 2. Old Testament (on creation) held that species individually designed by God; in 1700s, scientists believed match of organisms/environment evidence that God designed each
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This note was uploaded on 02/10/2010 for the course BIOL 112 taught by Professor Vaughn during the Spring '08 term at Texas A&M.

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Chapter 22 - Chapter 22: Descent with Modification (A...

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