BIOL1202 Test 1 Review

BIOL1202 Test 1 Review - CHAPTER 22 Concept 22.1: The...

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CHAPTER 22 Concept 22.1 : The Darwinian revolution challenged traditional views of a young Earth inhabited by unchanging species. Evolution can be defined as descent with modification . Scala Naturae and Classification of Species Darwin’s proposal that life’s diversity has arisen from ancestral species through natural selection was a radical departure from the prevailing views of Western culture. Ideas About Change Over Time In contrast to the principle that events in the past occurred suddenly by mechanisms not operating today, geologists Hutton and Lyell perceived that changes in Earth’s surface can result from slow, continuous actions still operating in the present time. Fossils : A preserved remnant or impression of an organism that lived in the past. Strata (Singular- Stratum) : A rock layer formed when new layers of sediment cover older ones and compress them. Paleontology : The scientific study of fossils. Catastrophism : The principle that events in the past occurred suddenly and were caused by different mechanisms than those operating today. Uniformitarianism : The principle stating that mechanisms of change are constant over time. Lamark’s Hypothesis of Evolution Lamark hypothesized that species evolve, but the mechanisms he proposed are not supported by evidence. Concept 22.2 : Descent with modification by natural selection explains the adaptations of organisms and the unity and diversity of life. Darwin’s Research Darwin’s experiences during the voyage of the Beagle gave rise to his idea that new species originate from ancestral forms through the accumulation of adaptations. He refined his theory for more than 20 years and finally published it in 1859 after learning that Wallace had come to the same idea. The Voyage of the Beagle Darwin’s Focus on Adaptation Adaptations : Inherited characteristics of an organism that enhances its survival and reproduction in specific environments. Natural Selection : A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics. The Origin of Species Darwin’s book proposed that evolution occurs by natural selection: Observations: Individuals in a population vary in their heritable characteristics. Organisms produce more offspring than the environment can support. Inferences:
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Individuals that are well suited to their environment tend to leave more offspring than other individuals. AND Over time, favorable traits accumulate in the population. Descent With Modification Artificial Selection, Natural Selection and Adaptation Artificial Selection : The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits. Natural Selection: A Summary
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This note was uploaded on 08/22/2010 for the course BIOL 1201 taught by Professor Wishtichusen during the Spring '07 term at LSU.

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BIOL1202 Test 1 Review - CHAPTER 22 Concept 22.1: The...

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