Description:
The invasion or fixation of a new genetic component is a longstanding research topic, dating back to the beginning of population genetics. Fixation quantifies the dynamics of a rare allele by describing the probability and the expected time for it to increase to a significant frequency within a population (through selective forces or genetic drift). Fixation is therefore an important factor in determining genetic diversity and the rate of evolution of species. These issues can be of direct practical concern. For example, conservation genetics often aims to maximize the genetic diversity of endangered populations, and health or agricultural programs aim to minimize the fixation probability of alleles for insecticide, drug, or vaccine resistance.

Analytical approximations exist to estimate fixation probability but are only valid under a limited range of assumptions. For more realistic situation, however, approximations available perform quite poorly. The goal of this project is to investigate how fixation can be described in more realistic conditions, considering for example sub-division of population and variation of migration rate between populations.

Prerequisites:
The student should be at ease with probability and stochastic processes. No prior background in biology is required.

References:
[1] Probability Models for DNA Sequence Evolution (2nd ed.), Rick Durrett, Springer, 2008.

Supervisors:
Dr. Olivier Lévêque (LTHI) * Email: olivier.leveque#epfl.ch * Office: INR 132 * Tel: 38112
Dr. Severine Vuilleumier (DEE - UNIL) * Email: severine.vuilleumier#unil.ch * Office: 2101 * Tel: 021 692 41 65

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