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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2710
DTSTART:20121102T203000Z
DURATION:PT1H0M0S
DTSTAMP:20260415T175338Z
LAST-MODIFIED:20121022T125734Z
LOCATION:2241 Chamberlin Hall (coffee at 4:30 pm)
SUMMARY:Anticipating sudden transitions in biological populations: Coo
 peration\, cheating\, and collapse\, Physics Department Colloquium\, J
 eff Gore\, Massachusetts Institute of Technology
DESCRIPTION:Natural populations can suffer catastrophic collapse in re
 sponse to small changes in environmental conditions\, and recovery aft
 er such a collapse can be exceedingly difficult. We have used laborato
 ry microbial ecosystems to study early warning signals of impending po
 pulation collapse. Yeast cooperatively breakdown the sugar sucrose\, m
 eaning that below a critical size the population cannot sustain itself
 . We have demonstrated experimentally that changes in the fluctuations
  of the population size can serve as an early warning signal that the 
 population is close to collapse. The cooperative nature of yeast growt
 h on sucrose suggests that the population may be susceptible to cheate
 r cells\, which do not contribute to the public good and instead merel
 y take advantage of the cooperative cells. We confirm this possibility
  experimentally and explore how such social parasitism can lead to pop
 ulation extinction.
URL:https://www.physics.wisc.edu/events/?id=2710
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