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ANALYSIS OF MULTI-SPECIES ECOLOGICAL AND EVOLUTIONARY DYNAMICS. 11. Evolution of biological networks toward the edge of biochaos and synchronization (S. Rinaldi)
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ANALYSIS OF MULTI-SPECIES ECOLOGICAL AND EVOLUTIONARY DYNAMICS 11. Evolution of biological networks toward the edge of biochaosand synchronization (S. Rinaldi) Field and laboratory data support the conjecture that biological networks evolve toward the edge of chaos and synchronization. Models of networks of interconnected communities. Biochaos, synchronization, Moran effect, and evolution of dispersal. Formal support to the conjecture. Furtherreadings Am. Nat. (2008) 171:430-442 Am. Nat. (1996) 148:709-718 Int. J. Bifurcat. Chaos (2007) 17:2435-2446 Ecole Normale Supérieure, Paris December 9-13, 2013
EVOLUTION OF BIOLOGICAL NETWORKS EVOLUTION BIOCHAOS AND SYNCHRONIZATION Evidence of chaos Conjecture S. Rinaldi, Plenarylecture, NOLTA, 2006 Evidence of synchronization Theoreticalsupport (main part) Conclusions
CANADIAN LYNX MACKENZIE RIVER BASIN Elton & Nicholson, JAE, 1942
DUNGENESS CRAB Higgins et al., Science, 1997
RED GROUSE ENGLAND Middleton, JAE, 1934
LEMMING ALASKA
GREAT TIT ENGLAND
DUNGENESS CRAB
General model of a single community environment community dimension dimension triangularstucture
Chaos and Liapunovexponents of a single community For chaos and Liapunovexponents(L.E.) seeStrogatz, Addison-Wesley, 1994. L.E. of are L.E. of and : envir. L.E. biolog. L.E. conditioned to largestbiolog. L.E. largestenvir. L.E. The community ischaoticif and/or is positive
The fourpossiblecases Chaos isexclusively due to environment 0 Chaos isexclusively due to biology 0 Chaos isprevalently due to environment 0 Chaos isprevalently due to biology 0 Thereis a hugeliterature on chaos
Pioneeringcontributions on chaos Constantenvironment Discrete time single population [May, Science, 1974] predation [Beddington et al, Nature, 1975] competition [Hassel & Connings, TPB, 1976] stucturedpopulations [Guekenheimer et al, JMP, 1977] Continuous time predation [Gilpin, AmNat, 1979] Lotka-Volterra [Arneodo et al, PhysLett, 1980] foodchain [Hastings & Powell, Ecology, 1991] plankton dynamics [Scheffer, JPR, 1991] Periodicenvironment Discrete time single population [Kot & Schaffer, TPB, 1984] Continuous time predation [Inone & Kamifukumoto, ProgTheorPhys, 1984] epidemics [Schaffer & Kot, JTB, 1985] plankton dynamics [Doveri et al, TPB, 1993] Chaoticenvironment predation [Colombo et al, AmNat, 2008]
Biochaos environment community Definition: Biochaos biochaos
Example environment prey-predator Rosenzweig-MacArthur model Rössler model (Colombo et al. AmNat 2008)
Evolutiontoward the edge of biochaos biochaos biochaos Hansen TPB 1992 Ferrière & Clobert JTB 1992 Ferrière & Gatto PRSB 1993 . . . Doebeli & Koella PRSB 1995 . . . biochaos
Sliding on the edge of biochaos biochaos Dercole et al. PRSB 2006
Synchronization of disconnectedcommunities Empiricalevidence: pathches are oftensynchronized Monet, 1873 Monet, 1873 Monet, 1873 Grenfell et al., Nature, 1998
Biochaos and synchronization of disconnectedcommunities Modernformulation of Moraneffect (Colombo et al., AmNat, 2008) Disconnectedcommunitiessynchronizeif and onlyif i.e., if and onlyifthereis no biochaos biochaos Bc S S sync Bc
Connectedcommunities 2 1 i j if and are notconnected if and are connected # connections to P The eigenvalues of importanttopologicalindicator Moreover, populations can disperse atdifferentrates,
Models of connectedcommunities 2 1 i j For the environment P For each patch where
Synchronization of connectedcommunities Master StabilityFunction[Pecora & Carrol, PRL, 1998; Jansen & Lloyd, JMB, 2000] If (i.e., ifthereisbiochaos) thenpatchessynchronizeprovideddispersals are sufficiently high. In particular, ifdispersals are balanced (), patchessynchronizeprovided sync
Example environment prey-predator Rosenzweig-MacArthur model Rössler model (Colombo et al. AmNat 2008)
Summary Bc S S Bc S S Bc Bc
Evolution of dispersal Dispersal can evolve Assumption are threeadaptive traits Dispersalisoftenassociated to costs Obvious consequence: evolutionreduceswhenpatches are synchronous Lessobviousconsequence: evolutionincreaseswhenpatches are notsynchronous [Holt & McPeek, AmNat, 1996] S predator dispersal, Dercole et al., IJBC, 2007 control parameter
The conjecture There are threepossibleancestralconditions S S S S S S S S S Bc Bc Bc Bc Bc Bc Bc Bc Bc
Conclusions S S Bc Bc Metapopulations evolve toward the edge of biochaos and synchronization Evolutionmakes patch behaviorcomplexbutsimplifies network behavior Genericallyweshouldexpectpopulations to be almostchaotic and almostsynchronous Whenevolutionis over dispersalisabsent (or verylow)