BS148HFinalReviewQuestions

- Bio Final 1 Use examples from texture or text to help explain(a the concepts and(b the processes of adaptation(c Explain at least three reasons

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Bio Final 1. Use examples from texture or text to help explain (a) the concepts and (b) the processes of adaptation. (c) Explain at least three reasons why adaptations are not ‘perfect.’ Concepts The text defines adaptation as: inherited characteristics of an organism that enhances its survival and reproduction in specific environments Maintained by current selection Measured by fitness: survival and reproduction. Adaptations meant to maximize fitness. Works better than alternates Example : Tail lengths in sparrows can be very long or very short. Longer tails correlated with quicker female attraction but shorter lifespan vs. Shorter tails correlated with slower female attraction and longer lifespan. A fitness tradeoff often takes place (form vs. function) Evolved in response to past selection Occurs in specific environments. A good adaptation in one place may be bad in another. Processes -Natural selection: process in which individuals with certain inherited traits leave more offspring than individual with other traits -Descent with modification -Artificial selection and sexual selection -If Random Mutation (possibly by gene cross-over) helps survival in natural environment, that mutation is further selected -Mutation is random but natural selection is NON-RANDOM Three reasons why adaptations are “better” than random but not perfect: You can’t get there from here Lack of genetic variation (selection > mutation) Transition phenotypes may be less fit There keeps moving – coevolution You didn’t really want to anyway Tradeoffs select for compromises Example : You can select for longevity in fruit flies and get correlated decrease in early reproduction Combinations of adaptive efficiencies to maximize fitness. You can but it will take time and luck Chance: selection only operates on existing variations, depends on chance mutations, drift, and quirks of history Time lags in response to novel selective environments Genetic correlations between traits create tradeoff by with time and luck genetic architecture can evolve too Gene flow can disrupt local adaptation. Speciation breaks gene flow and allows divergence 2. What is Life? Your answer should include (a) the properties listed in the text, readings and lecture and (b) a careful analysis of the criteria for detecting life on Mars. (c) Explain the
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strengths and weakness of each of the criteria and specify what level of biological organization these criteria can be applied to. Apply these properties and criteria to 1) real viruses 2) computer viruses 3) human fetuses and 4) the earth. Properties of Life: Order (low entropy) Regulation – Homeostasis (maintaining low entropy) Sensitivity – responsiveness Reproduction Evolutionary Adaptation – the fundamental property Mars criteria for life:
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This note was uploaded on 09/19/2011 for the course BIOLOGY 148H taught by Professor Getty during the Fall '10 term at Michigan State University.

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- Bio Final 1 Use examples from texture or text to help explain(a the concepts and(b the processes of adaptation(c Explain at least three reasons

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