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Unformatted text preview: General Biology II-Biology 102 Spring 2011/gpd Lecture Objectives Unit 1: Evolution Chapter 23. Evolution: The Modern Synthesis I. Genetics role A. Sexual recombination- ??? B. Mutations : a change in the DNA. It can be good or bad. Can eventually lead to evolutionary change because if an a species has an organism that has a mutation that is beneficial, that organism will survive and reproduce creating more organisms carrying on the mutation. This will lead to the mutation changing the species in the future if it is a good trait that helps them survive. II. Population Genetics A. Genetic variability Within populations : Average Heterozygosity(the average percent of loci that are heterozygous) Between populations: geographic variation (differences in the genetic compos. Of the separate populations), Clines( a graded change in a character along a geographic axis) B. Microevolution : evolutionary change below the species lever. change in the allele frequencies in a population over generations. Examples: change in the beak of a finch, bent grass, C. Hardy-Weinberg Equations & Equilibrium- helps determine frequencies and they show if freq. has changed. Sample problem p + q = 1 <<(LOOK AT SLIDE 7 ON LECTURE 2 to see how to use these equations) p 2 + 2pq + q 2 = 1 D. Conditions needed for equilibrium 1. Large population size Customerfirstname.lastname@example.org 2. No immigration-no gene flow2....
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