Study Guide for Biology

Study Guide for Biology - Study Guide for Biology I....

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Study Guide for Biology I. Natural Selection: A. Darwin’s Theory of Evolution by Natural Selection 1. Individuals within populations are variable 2. This variation is at east in part, heritable a. Darwin did not understand genetics 3. In every generation, some individuals are more successful at surviving and reproducing a. Survival of the fittest 4. The individuals with the most favorable variations, those who are better at surviving and reproducing, are selected. a. If all of these are true, then populations will change through time B. Natural Selection is a theory 1. Theory is a hypothesis with an explanatory power 2. Natural Selection is a theory because due to the long span of evolutionary change, one cannot see the actual changes to confirm evolution as fact. C. Some Common Misconceptions 1. Evolutionary change is accomplished by gradual and progressive change in traits a. Traits become gradually established in a population 2. Genetic variation is not important in evolution a. Variation is the raw material of evolution b. Dependent on differences of genetic traits and reproductive success 3. The environment causes traits to change over time a. Natural Selection acting on genetic variations is what causes the traits to change b. Environment affects the survival of traits after their appearance in the population D. Subtleties of Natural Selection 1. Selection is nonrandom, but not progressive 2. Selection occurs within generations, evolution occurs between generations 3. Selection is not forward looking or predictive 4. Selection acts only on existing traits, but new traits can evolve a. Mutation and Recombination b. Preadaptation (Panda’s thumb) 5. Selection acts on individuals, but the consequences occur in the populations (individuals are selected, but populations evolve) II. Proximate compared to ultimate causation in Science A. Proximate Causation 1. Mechanistic 2. Explains how something happens B. Ultimate Causation 1. Evolutionary 2. Explains why something happens III. The Demographic Cost of Sex A. Maynard-Smith Demographic Model of Sex 1. Asexual Reproduction a. One female produces four females, which each produce four more females b. End result 16 females 2. Sexual Reproduction
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a. One male and one female produce two males and two females. The two females then produce 2 male and 2 females. b. End result 4 males and 4 females 3. Results a. Explains the costs of having males in the population 1. Asexual reproduction results in 16 offspring 2. Sexual reproduction results in 8 offspring IV. Meiosis A. Vocabulary 1. Chromosome: structure made up of DNA and proteins; carries the cells hereditary information (genes) 2. Sex Chromosome: chromosome associated with an individual’s sex 3. Autosome: A non-sex chromosome 4. Sister Chromatids: The chromosome copies in a replicated cell 5. Homologous Chromosomes: In a diploid cell, chromosomes that are similar in size, shape and gene content 6. Non-sister Chromatids: the chromosome copies in homologous chromosomes
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This note was uploaded on 01/24/2010 for the course BIO 1311 taught by Professor Shinkle during the Spring '06 term at Trinity University.

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Study Guide for Biology - Study Guide for Biology I....

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