BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//jEvents 2.0 for Joomla//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:STANDARD
DTSTART:20220110T080000
RDATE:20220313T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20221106T010000
RDATE:20230312T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20231105T010000
RDATE:20240310T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20241103T010000
RDATE:20250309T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20251102T010000
RDATE:20260308T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20261101T010000
RDATE:20270314T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20271107T010000
RDATE:20280312T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:STANDARD
DTSTART:20281105T010000
RDATE:20290311T030000
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:America/New_York EST
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:20220313T030000
RDATE:20221106T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20230312T030000
RDATE:20231105T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20240310T030000
RDATE:20241103T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20250309T030000
RDATE:20251102T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20260308T030000
RDATE:20261101T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20270314T030000
RDATE:20271107T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20280312T030000
RDATE:20281105T010000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:America/New_York EDT
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
UID:1a0840b55e590722f09effe092273f14
CATEGORIES:Mathematical Physics Seminar
CREATED:20230111T115004
SUMMARY:Evolution in changing environments and driven disordered systems
LOCATION:Zoom
DESCRIPTION:<p style="background: white; text-align: left;">Abstract: Biological evolut
 ion is governed by the fitness landscape, a map from the genetic sequence o
 f an organism to its fitness. &nbsp;Here fitness denotes some quantitative 
 measure of reproductive success, such as the expected number of offspring. 
 A fitness landscape depends on the organism's environment, and evolution in
  changing environments is still poorly understood. After introducing the co
 ncept of fitness landscapes and their mathematical description, the talk wi
 ll focus on a particular model of antibiotic resistance &nbsp;evolution in 
 bacteria, where the drug concentration is an environmental parameter. Trade
 offs between adaptation to low and high concentration lead to a rugged land
 scape with an exponentially large number of fitness peaks. With evolutionar
 y dynamics that follow &nbsp;fitness gradients, resistance evolution under 
 slowly changing antibiotic concentration resembles the zero temperature dyn
 amics of &nbsp;a disordered spin system under quasistatic driving. Specific
 ally, the set of genetic sequences that form a fitness peak at some concent
 ration maps exactly to the metastable states in an equivalent Preisach syst
 em, a paradigmatic model of hysteresis in random &nbsp;magnets. Making use 
 of the conceptual tool of state transition graphs developed in the context 
 of driven disordered systems, we quantify the degree of genotypic and pheno
 typic reversibility in the response of the population to antibiotic concent
 ration &nbsp;cycling, and ask to what extent a memory of past concentration
  changes is stored in the current genetic sequence. The talk is based on jo
 int work with Suman G. Das and Muhittin Mungan.</p>
CONTACT:Joachim Krug - University of Cologne
DTSTAMP:20260827T103212
DTSTART;TZID=America/New_York:20230111T080000
DTEND;TZID=America/New_York:20230111T170000
SEQUENCE:0
TRANSP:OPAQUE
END:VEVENT
END:VCALENDAR