biol 1202 notes

biol 1202 notes - Descent with Modification: A Darwinian...

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Descent with Modification: A Darwinian View of Life Chapter 22 Two main ideas 1. Change over time of the genetic composition of a population 2. Decent of modern organisms with modification from preexisting organisms Evolutionary adaptation -Accumulation of inherited characteristics that enhance organisms ability to survive in specific environments Pre-Darwinian Theory of Evolution Lamarck In heritance of acquired characteristics -Bodies of living organisms are modified through the use or disuse of parts -These modifications are inherited by offspring -This idea turned out to be wrong Evolution by Natural Selection Darwin and Wallace developed the theory independently Darwin voyage of the Beagle Wallace-naturalist in Indonesia Natural Selection The unequal survival and reproduction of organisms due to environmental forces, resulting in the preservation of favorable adaptations Process “selects” from what is available in the gene pool New characteristics are not created on demand Pg. 458 chart
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Artificial Selection Selection breeding of organisms to encourage the occurrence of desirable traits Analogous to natural selection Concept 22.3 Evolution is supported by an overwhelming amount of scientific evidence *figure 22.13 * figure 22.14 Fossil Record Show change in organisms through time Change in types of organisms -Past organisms differ from present-day organisms -Many species have become extinct *figure 22.15 *figure 22.16 Homologous Structures May differ in function, but have similar anatomy Analogous structures Have similar functions & superficially similar appearance, but different anatomies (convergent evolution) Figure 22.17 Homologous Structures: Vertebrate Embryos All vertebrates share similar developmental genes Differences arise by some genes being expressed differently Homologous Structures: Biochemistry &Molecular Biology
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DNA is universal genetic material All life forms use approximately the same 20 amino acids to make proteins All use ATP as the primary form of cellular energy All use RNA and ribosomes to make protein Figure 22.19 Biogeography Geographic distribution of species -closely related species tend to be found in the same region Convergent evolution -Organisms evolved from different ancestors, but living in similar environments - They evolve analogous structures Figure 22.20 What provides the selective pressure in artificial selection? -humans Which of the following pairs of structures is least likely to represent homology? -The legs of a bird and those of an insect The Evolution of Populations Chapter 23 The Smallest Unit of Evolution One common misconception about evolution is that individual organisms evolve during their lifetime
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Evolutionary processes (e.g., natural selection) acts on individuals, but populations evolve Concept 23.1: Mutation & sexual recombination produce the genetic variation that makes
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This note was uploaded on 07/13/2009 for the course BIOL 1202 taught by Professor Gregg during the Summer '08 term at LSU.

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biol 1202 notes - Descent with Modification: A Darwinian...

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