firstclass - Decent with Modification(Darwinism Two main...

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Decent with Modification (Darwinism) Two main ideas 1. Change over time of the genetic composition of a population over time (one generation to next change traits expresed) 2. Decent of modern organisms with modification from preexisting organisms (over long periods of times share common ancestors) Evolutionary adaptation - Accumulation of inherited characteristics that enhance organisms’ ability to survive in specific environments (traits that help survive) Pre-Darwinisan Theory of Evolution Lamarck - Inheritance of acquired characteristics 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 (divinty major at cambridge) o Studied fossils and came to conclusion evolution (did not publish ideas) o Took wallaces work to scientists o Published origins of life
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- Wallace – naturalist in Indonesia o Protégé of Darwin (came up with same idea and wrote articles for publication) Natural Selection - 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 (some animals better suited for survival than others) Mechanism behind Natural Selection (pg 458)-flow chart - Not every animal lives (some that live do not reproduce) - Populations tend to grow exponentially - Popluations in nature remain constant (only so much food/water/space)- limited survival o Leads to competiton among animals to fight for food o Fight for attractive mates (more stronger survival skills) o Survival skills- Some inherited/some enviornement /(most are genes)= Evolution 1/22/09 Artificial Selection - Selective breeding of organisms to encourage the occurrence of desirable traits - Analogous to natural selection (fig 22.9)
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- Artificial selection show that over time leads to genotypic changes and phenotypic changes Concept 22.3 Evolution is supported by an overwhelming amount of scientific evidence - One line of evidence: (figure 22.13) o Predator: killfish feed on Prey: young guppies o Pike-cichlid preys on mature guppie fish
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This note was uploaded on 02/26/2010 for the course BIOLOGY Bio 1201 taught by Professor Wischusen during the Fall '09 term at LSU.

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firstclass - Decent with Modification(Darwinism Two main...

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