biology notes EXAM 1

biology notes EXAM 1 - What is evolution and adaptation Two...

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What is evolution and adaptation? Two main ideas 1. Change over time of the genetic compositions of a populations 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 Inheritance of acquired characteristics ( Lamarck’s idea) Used giraffes and that in past they had shorter legs and necks. They evolved by stretching necks and legs and it became longer. o Bodies of living organisms are modified through the use or disuse of parts o These modifications are inherited by offspring o 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 proposed by Wallace and Darwin 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. Environment changes, if there are no genotypes in the environment, it will not pass off offspring, needs to have some kind of capability to survive. Figure from page 458 All populations are capable of very rapid reproduction. In order to carry out change, some species need to reproduce faster and better than others. Artificial Selection Selective breeding of organisms to encourage the occurrence of desirable traits Analogous to natural selection 22.3 Evolution is supported by an overwhelming amount of scientific evidence. Fig.22.13 Natural Selection and HIV resistance
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Within a few weeks of treatment with the drug 3TC, a patients HIV population consists entirely of 3TC resustant viruses. How is it explained? Few drug resistant viruses were present at start of treatment and natural selection increased their frequency. 01/16 Fossil Record Show change in organisms through time Change in types of organisms o Past organisms differ from present-day organisms o Many species have become extinct Remains of organisms that are buried in sand and such Darwinists rarely mention the whale because it presents them with one of their most insoluble problems. They believe that somehow a whale must have evolved from an ordinary land dwelling animal, which took to the sea and lost its legs. A land mammal that was in the process of becoming a whale would fall between two stools – it would not be fitted for life on land or sea and would have no hope for survival. Homologous and Analogous Structures Homologous structures May differ in function,but have similar anatomy Analogous structures Have similar functions and superficially similar appearance, but different anatomies ( convergent evolution ) Homologous structures: mammalian forelimbs similar in humans, cats, whale, and bat
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biology notes EXAM 1 - What is evolution and adaptation Two...

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