?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=https%3A%2F%2Fpure.iiasa.ac.at%2Fid%2Feprint%2F4997%2F&rft.title=The+Evolution+of+Cooperation+in+Spatially+Heterogeneous+Populations&rft.creator=Ferriere%2C+R.&rft.creator=Michod%2C+R.E.&rft.description=A+challenging+problem+in+sociobiology+is+to+understand+the+emergence+of+cooperation+in+a+nonsocial+world.+Recent+models+of+the+iterated+Prisoner's+Dilemma+(IPD)+game+conclude+that+population+mixing+due+to+individual+mobility+limits+cooperation%3B+however%2C+these+models+represent+space+only+implicitly.+Here+we+develop+a+dynamical+IPD+model+where+temporal+and+spatial+variations+in+the+population+are+explicitly+considered.+Our+model+accounts+for+the+stochastic+motion+of+individuals+and+the+inherent+nonrandomness+of+local+interactions.+By+deriving+a+spatial+version+of+Hamilton's+rule%2C+we+find+that+a+threshold+level+of+mobility+in+selfish+always-defect+(AD)+players+is+required+to+beget+invasion+by+social+'tit+for+tat'(TFT)+players.+Furthermore%2C+the+level+of+mobility+of+successful+TFT+newcomers+must+be+approximately+equal+to+or+somewhat+higher+than+that+of+resident+defectors.+Significant+mobility+promotes+the+assortment+of+TFT+pioneers+on+the+front+of+invasion+and+of+AD+intruders+in+the+core+of+a+cooperative+cluster.+It+also+maximizes+the+likelihood+of+TFT+retaliation.+Once+this+first+step+whereby+TFT+takes+over+AD+is+completed%2C+more+generous+and+perhaps+more+suspicious+strategies+may+outperform+and+displace+TFT.+We+derive+the+conditions+under+which+this+continued+evolution+of+more+robust+cooperative+strategies+occurs.&rft.publisher=WP-96-029&rft.date=1996-06&rft.type=Monograph&rft.type=NonPeerReviewed&rft.format=text&rft.language=en&rft.identifier=https%3A%2F%2Fpure.iiasa.ac.at%2Fid%2Feprint%2F4997%2F1%2FWP-96-029.pdf&rft.identifier=++Ferriere%2C+R.+%3Chttps%3A%2F%2Fpure.iiasa.ac.at%2Fview%2Fiiasa%2F1248.html%3E+%26+Michod%2C+R.E.++(1996).++The+Evolution+of+Cooperation+in+Spatially+Heterogeneous+Populations.+++IIASA+Working+Paper.+IIASA%2C+Laxenburg%2C+Austria%3A+WP-96-029+++++