BIO 203 1st Edition Lecture 3 Outline of Last Lecture II. Questions to ask to identify speciesIII. Taxonomya. Historyb. Bionomial nomenclaturec. Basic Linnean Ranksd. Nomenclature below species levelOutline of Current Lecture II. Mechanisms of EvolutionA. MutationB. Gene FlowC. Natural SelectionD. Genetic DrifE. Non-Random MatingIII. Convergent EvolutionCurrent LectureIV. Mechanisms of Evolutiona. Mutationi. The ultimate source of genetic variationii. Mutations create new alleles (& new phenotypes)iii. Without variation, evolution could not occuriv. When a mutation occurs, the new allele could be harmful, neutral, or beneficialv. Organisms can’t predict (or direct) the outcomeb. Gene Flowi. Also called migrationii. Introduces new alleles into a populationc. Natural Selectioni. Requirements:1. Phenotypic variation in a population2. This variation must be heritable3. This variation must influence the reproductive success (fitness) of individuals in the populationd. Genetic DrifThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Allele frequency change by sampling error, some individuals surviving and reproducing randomlyii. If unopposed by some other evolutionary mechanism, genetic drif will result in loss of allelesiii. Alleles that are less common are most likely to be eliminated from a population due to chancee. Non-Random Matingi. Organisms choose their mates purposely, not just due to chanceii. Humans are an example of thisiii. Extreme example of non-random: inbreedingiv. Extreme example of inbreeding : self-fertilization; eventually, alleles will become fixedV. Convergent Evolutiona. Organisms that are not at all closely related develop characteristics that are strikingly similarb. This occurs because they all adapt to similar environmentsc. An example of convergent evolution is: earthworm, underground amphibian, andthe parasitic roundworm all have similar, tubelike
View Full Document
Unlocking...