The extent to which traits or populations may respond to selection (evolvability) is not constant across traits or taxa. What factors affect evolvability is a central question in evolutionary biology. One factor that is thought to have a large effect on evolvability is the amount of standing genetic variation present in a population. Non-directional selection (stabilizing, disruptive, fluctuating and sexual conflict) has been observed to increase or decrease the genetic variation in traits and populations, and is thought to result in differential evolvability. This study looks at the effects of various forms of non-directional selection on subsequent evolvability in an artificial selection experiment using Drosophila melanogaster. Artificial selection was imposed on a wing trait in Drosophila melanogaster to simulate 4 different forms of non-directional selection for 10 generations followed by 10 generations of directional selection to examine the response to a new selective pressure. Increases in phenotypic variance in the disruptive lines were observed, however directional selection revealed no differences in evolvability among the various non-directional selection treatments. If more generations of non-directional selection and/or more generations of directional selection were analyzed, a significant difference may be observed.
|Commitee:||Johnson, Darren, Stankowich, Theodore|
|School:||California State University, Long Beach|
|School Location:||United States -- California|
|Source:||MAI 56/01M(E), Masters Abstracts International|
|Subjects:||Evolution and Development|
|Keywords:||Artificial selection, Evolvbaility, Heritability|
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