22nd Annual Student Research Conference
Separating the Effects of Genetic Drift and Natural Selection using a Modification of Tajima's D Statistic
Dianne E. Kopp* and Karen E. O'Connell
Dr. Anton Weisstein and Mr. Pamela J. Ryan, Faculty Mentors
Several statistical measures have been devised to infer past and/or present evolutionary forces from patterns of genetic diversity in sequence data. Tajima's D detects increases or decreases in overall genetic diversity, but cannot assess the relative contribution of genetic drift vs. natural selection. By applying Tajima's D analysis separately to synonymous (Dsyn) and nonsynonymous (Dnon) mutations, we can separate the effects of drift from those of selection. Specifically, Dsyn measures the effects of drift within a population, while Dnon - Dsyn measures the effects of selection. Critical values for Dsyn and Dnon - Dsyn will be generated under a model of neutral evolution. We will then analyze data obtained from computer simulations of specific evolutionary and demographic histories to measure our methods ability to correctly infer the populations history. Although our model reflects the details of HIV evolution, we anticipate our extension of Tajima's analysis will have broad application.
Keywords: Natural Selection , Genetic Drift , Tajima's D , Evolutionary forces, Computer simulation
Topic(s):Mathematical Biology
Presentation Type: Oral Paper
Session: 55-2
Location: VH 1328
Time: 3:00