Bio lec 12

Bio lec 12 - Bio 101, Fall 2008: October 23/28 Unifying...

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Unifying Interlude: “Nothing in Biology Makes Sense Except in the Light of Evolution” The Human Organism I: Human Evolution TEXT: Angier: Chapter 6 (Evolutionary Biology) Buxton and Turney: Chapter 5 (Genes Evolving) Loomis: Chapter 8 (The Origin of Life and Evolution of Man) Human Evolution Biological Evolution: Summary of General Principles Change in lineages(lines of decent) over time -change in the alleles and allele frequencies is a change in the alleles and allele frequencies in populations over time -new allels Observable fact of nature Very robust body of theory that explains how this happens Individuals -units of selection Population s-units of evolutionary change -variations -an individual only has. ..at most…2 different alleles Terms and Concepts: Populations evolve, not individuals. Species, populations, gene pools. Genotype and phenotype. Polygenic and single locus (Mendelian) traits. Agents of allele frequency change Mutation: The ultimate source of new alleles (variation for natural selection) Gene flow: Between populations Genetic drift: Small populations Selection Genetic equilibrium. Adaptation. Modes of natural selection Stabilizing- Directional- Disruptive- Natural selection and human affairs: Antibiotic, pesticide, herbicide resistance. Artificial selection: On the farm and in the lab. Sexual selection: Sexual dimorphism and secondary sexual traits. Female mate choice. Male-male competition. Necessary conditions for allele frequency change (c.f., “Darwin’s logic”): Phenotypic variation. Some of the variation must have a genetic basis, i.e., it must be heritable. For selection to occur, heritable variation must confer fitness differences. Genetic Variation in Populations The gene pool: the total of all genotypes in a population. Alleles: different forms of a gene at a locus. Individuals in a population vary; A population evolves through changes in allele frequency. Classes of mutation: Neutral mutations (mutant allele just as good as the other form). Lethal or deleterious mutations (largely purged from the population).
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This note was uploaded on 01/18/2012 for the course BIO 102 taught by Professor Brey during the Fall '08 term at Rutgers.

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Bio lec 12 - Bio 101, Fall 2008: October 23/28 Unifying...

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