?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=What+does+it+take+to+evolve+behaviorally+complex+organisms%3F&rft.creator=Calabretta%2C+Raffaele&rft.creator=Di+Ferdinando%2C+Andrea&rft.creator=Wagner%2C+G%C3%BCnter+P.&rft.creator=Parisi%2C+Domenico&rft.subject=Evolution&rft.subject=Neural+Nets&rft.description=What+genotypic+features+explain+the+evolvability+of+organisms+that+have+to+accomplish+many+different+tasks%3F+The+genotype+of+behaviorally+complex+organisms+may+be+more+likely+to+encode+modular+neural+architectures+because+neural+modules+dedicated+to+distinct+tasks+avoid+neural+interference%2C+i.e.%2C+the+arrival+of+conflicting+messages+for+changing+the+value+of+connection+weights+during+learning.+However%2C+if+the+connection+weights+for+the+various+modules+are+genetically+inherited%2C+this+raises+the+problem+of+genetic+linkage%3A+favorable+mutations+may+fall+on+one+portion+of+the+genotype+encoding+one+neural+module+and+unfavorable+mutations+on+another+portion+encoding+another+module.+We+show+that+this+can+prevent+the+genotype+from+reaching+an+adaptive+optimum.+This+effect+is+different+from+other+linkage+effects+described+in+the+literature+and+we+argue+that+it+represents+a+new+class+of+genetic+constraints.+Using+simulations+we+show+that+sexual+reproduction+can+alleviate+the+problem+of+genetic+linkage+by+recombining+separate+modules+all+of+which+incorporate+either+favorable+or+unfavorable+mutations.+We+speculate+that+this+effect+may+contribute+to+the+taxonomic+prevalence+of+sexual+reproduction+among+higher+organisms.+In+addition+to+sexual+recombination%2C+the+problem+of+genetic+linkage+for+behaviorally+complex+organisms+may+be+mitigated+by+entrusting+evolution+with+the+task+of+finding+appropriate+modular+architectures+and+learning+with+the+task+of+finding+the+appropriate+connection+weights+for+these+architectures.&rft.date=2001&rft.type=Departmental+Technical+Report&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F2324%2F3%2FWhatDoesItTake.pdf&rft.identifier=++Calabretta%2C+Raffaele+and+Di+Ferdinando%2C+Andrea+and+Wagner%2C+G%C3%BCnter+P.+and+Parisi%2C+Domenico++(2001)+What+does+it+take+to+evolve+behaviorally+complex+organisms%3F++%5BDepartmental+Technical+Report%5D++++(In+Press)++&rft.relation=http%3A%2F%2Fcogprints.org%2F2324%2F