Evolution of Cooperation
• How do you direct more benefit to
cooperators vs. cheaters?
• How would you ever get a mutualism if both
are costly?
Anaerobic methane oxidation (AOM)
Sulfate
Reducing
Bacteria
methane is oxidized with sulfate as
the terminal electron acceptor:
CH4 + SO42- → HCO3- + HS- + H2O
Methanotrophic
Archaea
• Important reducer of greenhouse gas emissions
(90% of marine methane from marine sediments oxidized by AMO)
• Unable to culture in lab – could be obligate syntrophy
• Unclear which intermediates are exchanged
Structured populations and Haystack
model
(John Maynard Smith)
Simpson’s
Paradox
Chuang et al, Science 2009
W(defector)
Prisoner’s Dilemma
(Turner & Chao, 1999. Nature)
“Snowdrift Game”
Cooperation in Myxococcus
(Kuner & Kaiser, 1982)
(Fiegna & Velicer, 2003; Velicer & Yu, 2003)
(Fiegna et al., 2006. Nature)
Monday (11/21):
Class Presentations!
Monday (11/28):
Evolution of Pathogens