<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div><u style="font-weight: bold; ">The <a href="http://www.ped.fas.harvard.edu/">Program for Evolutionary Dynamics</a> presents</u><b>:</b></div><div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>"<a href="http://www.ped.fas.harvard.edu/events/seminar/abstracts/9-9-11.html"><b>Evolutionary game dynamics in finite populations – Fixation times.</b></a>"</div><div><br></div><div>by <a href="http://www.evolbio.mpg.de/~altrock/">Philipp Altrock</a> (Max Planck Institute for Evolutionary Biology)</div><div><br></div><div><u><b>Abstract</b></u><b>:</b></div><div><p class="MsoNormal" style="text-align: justify; ">The evolution of finite populations is analyzed in the framework of stochastic evolutionary game dynamics. Often, one is interested in the probability that a sub-group of individuals that mutated to a new strategy spreads in the population and reaches fixation. I focus on the time such a fixation event is expected to take. A concept that allows a deeper analytical insight is weak selection. It considers only small deviations from neutral evolution, i.e., when all strategies perform equally well, and is widely believed to be a very relevant case in biology: A mutant strategy can be expected to only make a small contribution to the mutant’s overall reproductive success.<o:p></o:p></p><p class="MsoNormal" style="text-align: justify; ">Various aspects of the fixation times under weak selection (and slightly stronger) can be addressed: How do the mean exit times depend on the fact that the reproductive success of a strategy changes with the composition of the population? How universal are the most common weak selection results when comparing the two most important classes of birth-death processes? How can the surprising effect be tackled that a beneficial mutation can take longer than any neutral mutation when taking over a population (slowdown)? And how does this slowdown depend on the system size?<o:p></o:p></p>An example is the migration-selection balance in populations that ‘play a coordination game’ (evolutionary dynamics of underdominance) and are distributed over ecological patches. Fixation/extinction times can serve as a quantity that characterize long phases of mutant persistence for migration below a critical threshold.</div><div><br></div><div><b><u>When</u>:</b> 3:00pm, Friday, September 9th, 2011</div><div><br></div><div><b><u>Where</u>:</b> 1 Brattle Square, 6th floor, Cambridge, MA 02138 (<a href="http://www.ped.fas.harvard.edu/location/">link to map/directions</a>)</div><div><br></div><div>For more info on the <a href="http://www.ped.fas.harvard.edu/events/seminar/">PED Seminar Series</a>, please contact: <a href="mailto:mwojcik@fas.harvard.edu">mwojcik@fas.harvard.edu</a></div><div>
<span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br>———<br>Michael John Wojcik<br>Staff Assistant<br>Program for Evolutionary Dynamics, Harvard University<br>1 Brattle Square, 6th Floor, Cambridge, MA 02138<br><a href="http://www.ped.fas.harvard.edu/">http://www.ped.fas.harvard.edu/</a><br>Room 623<br>Office: (617) 496-4737<br>Fax: (617) 496-4629<br><a href="mailto:mwojcik@fas.harvard.edu">mwojcik@fas.harvard.edu</a></div></span></span>
</div>
<br></div></div></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Joyce Roberge</div><div>Undergraduate Program</div><div>Biology Education Office 68-120</div><div>Massachusetts Institute of Technology</div><div>31 Ames Street</div><div>Cambridge, MA 02139</div><div>617-253-4718</div><div>fax: 617-258-9329</div><div>email: <a href="mailto:roberge@mit.edu">roberge@mit.edu</a></div><div><br></div><div><br></div></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
</div>
<br></body></html>