Artificial Life: An Overview

345 Pages·1995·17.135 MB·English

by  Christopher G. Langton

ArtificiLailf e
Complex Adaptive Systems
JohnH .H ollanCluids,t opheLarn gton,a ndS tewart W.Wi lsona,d visors
Adaptationi nN aturala ndA rtificSiayslt ems: AnI ntroducAtnoarylysis with Applicatitoons
·
BioloCogyn,t ro�a ndArtifu:iaIInteOigence
John H.H olland
Toward aPra cticoefA utonomSoysust ems: Proceedingso ftFbiers Etu ropean Conferencoen
ArtificLiaifle
editbeydF rancisJc.Vo a relaan d:P auBlo urgine
GeneticPro grammingOn: tbProeg rammingo fC omputersM eabyns ofN aturaSle lection
JohnR .K oza
FromA nimatlso Ani2:m Proactseed ingso ftSecboen dI nternational ConferenocneS imulatoifo n
AdaptiBvee bavior
editbeydJ ean-ArcaMdeyy erH,e rbertL .R oitbalnadtS ,t ewaWrt. W ilson
IntelligBenetb aviionrA nimaalsn dR obots
DaviMdc farlaannddTh omas BOsser
Advancesi nG enetProigcr amming
editbeydK enneEt.hK innearJ,r .
Genetic Programmingn: AutomaDistciocvery ofR eusablePro grams
JohnR .K oza
Turtles,T ermitesa,n dT rafficJ ams: Explorations inM assively ParallelM icroworlds
MitchReels nick
From AnimatlsoA nima3ts:Proce edi ngosf tbThei rdI nternationCaoln ferencoen S imulatoiofn
AdaptiBvee bavior
editbeydD aveC liffP,h ilHiups banJdse,a n-ArcadyM eyera,n dS tewaWrt. W ilson
ArtificLiifaeIV:l Proceedings oft bFeo urtIbn ternationWaolrks bopo nth eS yntbesisa ndS imula­
tioonfL iviSnysgt ems
editbeydR odneAy. B rooksa ndP attMiaee s
ComparatApiproave cbest oC ognitiSvec ience
editbeydH erbeLrt.R oitbalnadJt e an-ArcadyM eyer
ArtificLiaifle A:n Overvi ew
editbeydClui stopheGr. La ngton
ArtificiLailf e
AnO verview
editbeydC hristoGp.hLa enrg ton
A BradfoBrodo k
The MIT Press
CambridgeM,a ssachusetts
LondonE,n gland
Seconpdri ntin1g99,6
(0 1995M assachusIentsttsi toufTt eec hnology
Allr ighrtess erveNdo. p arto ft hiboso k may ber eproducinea dn yf onn bya nye lectroonri c
mechanimceala ns( includpihnogt ocopyriencgo,r dionrgi ,n fonnatisotno raagned r etrieval)
withopuetnn issiionnw ritifnrgo mt hep ublisher.
Printeda ndb oundi nt heU niteSdt atoefsA merica.
Libraryo fC ongreCsast aloging-in-PDuabtlai cation
Artificial Lifaen:o vervie/we ditebdy C hristopheGr. La ngton.
p. cm.4Complexa daptivsey stems)
"AB radfordBo ok."
Includbeisb liographreifcaelr enc(eps.) a ndi ndex.
ISBN0 -262-91-211 8
1.B iologiscayls ms-t--Coe mputesri mulat2i.Bo ino.l ogsiycastems-Sli mulation methods. 3.
Artificial
IntelligIe.Lan ncgtoen., ChristopGh.en r. Se ries.
QH324.724. A1995
574''.1031-<1 c20 94-46217
CIP
Contents
Foreword vii
EditoIrn'tsr oduction ix
ArtificialL ifaesa T ool( oBri ological CharleTsa ylaonrd D aviJde fferson 1
Inquiry
Cooperatioann dC onununitSyt ructurein KristianUn dgrena ndM at,5G . 15
ArtificEicaols ystems Nordahl
ExtendeMdo lecular EvolutionaryP .BS icohluosgtye:r 39
Artificial LiBfrei dgintgh eG apB etween
Chemisatnryd B iology
VisuaMlod elso fM orphogenesis przemyslParuws inkiewicz 61
The ArtificialL ifeR oots ofA rtificial LucS teels 75
Intelligence
TowarSdy nthesiArtifizciinagl N eural MichaGe.lD yer 111
Networktsh aEtx hibCiootp erative
IntelliBgeehnatv iSoorm:eO penI ssuine s
ArtificialL ife
ModelinAgd aptiAvuet onomous AgentsP attiMea es 135
Chaoass a S ourcoefC omplexaintdy KunihiKkaon eko 163
Diversiint Eyv olution
An EvolutioAnpapryr oatcohS ynthetic Thomas S.Ra y 179
BioloZgye:n a ndt heArt ofC reatLiinfge
BeyonDdi giNtaaltu ralism WalteFro ntanGau,n tWearg nera,n d 211
LeoW. Buss
LearningA bouLtif e MitchReels nick 229
Bookosn Art ificiaLifle andR elatTeodp ics DaviGd. S tork 243
ComputVeirru seassArt ificiaLlif e EugenHe. S pafford 249
Contents
GenetAligco rithms andArt ificiLailf e MelanMiiet chaenldl 267
Stephanie Forrest
ArtificialL ifaesP hilosophy DaniDeeln nett 291
Levelso fF unctional EqiuinRv eavleersnec eS tevHaanm ad 293
Bioengineering
Why DoW e NeedArt ificiaLlif e? EriWc. Bonabeaanud G uyTh eraulaz 303
Index 327
vi
Foreword
ChristoGp.hLa enrg ton
Editor-in-Chief
SantFae I nstitute
Thisb ooki si ntendaesad h igh-lienvdeeltx o t heA rtificiLailfe en terprIitps reo.v ides
a poinotfe ntrtyot hefi elfdo bro tht hen ewcomearn dt hes easoned resaelairkceh.e r
The essaiynst hibso oki ntrodtuhceme a nys ubdiscipolfArti infiecsi aLli faen do rganize
a largbeo dyo fc itatitootn hsel iteraitntu hreefi eld.
Iw oulrde commentdh ibso oka sa ne xcellteenxftto arg raduasteem inoanrArt ificial
Lifaec,c ompanbieyrd e adindgrsa wnf romt hec itatitoanisl otroet dh ep rofessoorr 's
thes tudenitn'tse rests.
AsA rtificLiiaflie sa h ighilnyt erdiscifipelliddn,ra arwyi rnegs earcfhreoramsc rotshse
academaincd s cientsipfiecc trutmh,e a uthohrasv em adea ne xtreaf fotrtom aket heir
essacyosm prehenstiobr leea defrrso mo utsitdhee iorw np articudliasrc iplTihneeys .
haved efinetde chnitcearlm wsh ernee edeadn dp rovidbeadc kgroumnodt ivatfioorn
techniqaunedsa pproacthheasmt i ghott herwirseeq uiirne- depktnho wledogfes ome
highslpye cialbiozdeyod f t heorThyu.s ,t hibso oks houlpdr ovaec cessitboal ney one
witha moderabtaec kgrouinntd h es ciences.
Ih avem adea specieaflf otrto i nclundoeto nlsyc ientainfidec n gineerpianpge rs,
buta lsroe vieowfss omeo ft hep hilosopahnidcs aolc iiasls ueassi, ti sj usatsi mportant
tou ndersthaonwda fielfidt isn ttoh ew ebo fs cienacneds ocieatsiy ti st ou nderstand
thei nterdneatla iolft sh efi eld.
ChristoGph.Le arn gton
EditoIrn'tsr oduction
ChristoGp.hLa enrgt on
Editor-in-Chief
SantFae I nstitute
Artificial Life.
Thibsoo k consiosftst hefi rstth reies suoefs Thesei nitiisaslu ceosn tain
a specisaelot f o vervieawr ticcloenst ribbuytm eedm berosf t hee ditobroiaarlo df t he
journal.I nt hesaert icleeasc,he dithoars a ttemptteord e viehwi so rh ero wnt hread
ofs peciinatle rewsitt hitnh eb roaadn dd ivertsaep esotfryr esearecffho rtst hahta ve
comet ob ea ssociawtietClthh e term" ArtificialL if"e I.ng enereaalc,h a rticcloenta ins
a biotf h istoornya particruelsaera rtcohp iac r,e vieowfs omeo ft hem orei mportant
problemas d,e scripotfith oen m ostp romisitnegc hniqaunedms e thods foard dressing
thesper oblemasn,da viewt owartdh efu turew,i ths uggestiooftn hse i mpactth at
ArtificialL iftee chniqwuielhsla veo no uru nderstandionfgt heb iologpihceanlo mena
undesrtu dy.
Thep rimapryu rposoeft hiisn itsieatol f o vervieawrt icliests o " primet hep ump"
fofurt urree searicnth h efi elodf Artifi cial Lifteh,e resbtyi mulafuttuinrge c ontributions
tot hej ournailt seTlhfe.y a rea lsion tendteodh eldpe finea ndd elinetahtefie e lodf
Artificial Life moret horougthhlayhn a sbe en doneu ntniolw .
Thet erArtifimc ial Liflei teramlleya ns" limfaed eb yh umanrsa thtehra bny n ature."
As youw ilsle ei nt hesaer ticArtifilceisa,l Lifiesm anyt hintgosm anyp eoplaen,d I
wilnlo ta ttemtpotg ivae c oncidseefi nitoifoi nth ereI.n f acArtifitc,i al Lifise n oty et
readtyob ec onstrainbeydq uicakn ds hortd efinitionsfi-tehleid ss tiilntl h ep roceosfs
definiintg sealfsi, s p ropefro arn yn ewd isciplTihneae rt.i cline tsh ivso lumcea refully
stakoeu tc laimtso c ertaianr eaosfs tudbyu,tt heriesf amro rei ntelletcetrurailot uotr y
therwea ititnogb ed iscovearneddl aicdl aimt o.
Among allo ft het hintghsa Artifitc ialL ifei so rw ilclo met ob e,h oweveirti, sp robably
safteo s ayt hatth efi elads a wholree preseannta st temtpoti ncreavsaes ttlhyer ole
ofs yntheisnti hse s tudoyfb iologpihceanlo menSay.n thehsaisps l ayead v itraoll ien
theg roundionfmg a nys cientdifiics ciplbienceasu,is tee xtentdhsee mpiridcaatla base
uponw hicthh et heooryf t hed iscipilsib nueilb te yontdh eo ftenh ighlayc cidensteatl
ofe ntittiheansta tuhraep penetdol eavaer ounfdo ur st os tudy.
Taket hefi elodf c hemistarys a ne xamplIen:t hee arlisetsatg oefsr esearicnhtt oh e
constitouftmi aotnt epre,o plteo oskt ocokft hek indso fc hemiccaolm poundtsh anta ­
turhea dp rovidtehde mw ithc,a talogaunedcd l assitfiheedm a,n alyztehde mb yt aking
thema parintt ot heciorn stitpuieenctea sn,dt heann alyztehdep ieceTsh.i wsa sfi nea s
faars i tw entb,u tt herwea sa greadte aolf a ccideanntdh istorical procesisn involved
thed eterminaotfti hoenk indosf c hemiccaolm poundtsh anta turhea ppenetdol eave
arounfdo sr tudayn,d i tw oulhda veb eenv eryd iffictuolo tb servteh el aw-regularities
int heh ighilryr egualnadur n iqusee to fc ompoundtsh aeta rlrye searchhaeprpse ned
toh avea vailafbolrse t udyIt.w aso nltyhr ougthh ep roceosfss ynthesis-putthtei ng
constitpuieenctoe fsm attteorg ethinen re wa ndd ifferweanyts-t hatr esearcwheerres
ablteo e xtentdh es eotf c hemiccaolm poundasv ailabfloesr t udfya bre yontdh ei rreg­
ulasre ptr ovidteotd h emb yn aturIetw. a so nlwyi thtihne c onteoxftt himsu chl arger
seto f" possibclhee"m iccaolm poundtsh arte searcwheerresa blteo s eeb eyontdh e
accidentalo fnt ahte"u nraetu ral" chemical acnodmg ploiumnptdshseer, e gulariint ies
ChrsitophGe.rLa ngton EditoIrn'tsr oduction
thec onstitouftm iaotnt eTro.h avea theooryf t hea ctuailti, sn ecesstaoryu nderstand
thep ossible.
Thes ituatiismo unc ht hes amei nb iologTyh.e s etof b iologeinctailt pireosv ided
tou sb yn aturber,o aadn dd iverassei ti si,s d ominatebdy a ccideanntdh istorical
contingenWcey tru.s t implictihtalttyh erwee rel awful regularaittw ioerski nt he
determinaotfti hoins bsuetit it, su nliktehlaywt e w ildli scomvaenry o ft hesree gularities
byr estriocutrisnegl ovnelsty o t hes eotf b iologeinctailt tiheansta tuarcet uaplrloyv ided
usw ithR.a thesru,c hr egularwiitliblee fs o unodn lbyy e xplortihnemg uchl argesre t
ofp ossibblieo logeinctailt ies.
Manyb iologhiasvtess p eculawtiesdtfu llayb ou"tr ewindtihnetg a peo"fe volution,
startitnhgep roceosvse arg aifnr oms lighdtilffye reinnti tcioanld itioWnhsa.tw ould
emerge?W hatw ouldb e thes ame?W hatw ouldb ed iffereWnet s?e nsteh atth e
evolutionary ttrhaajdtei cdit nfo aryc t oocnce uarr tihsj usotn eo uto fa v asetn sembolfe
possiebvleo lutiotnraarjye cs-eatorcihel eaditnoag biolotghya cto ulhda veh appened
inp rincibpulted ,i dni'ntf acsto lefloyrr easoonfsa ccidecnotm binewdi tcho mmon
genetdiecs cenWte.. s ensteh atth er egulariwtei seese wko ulbde r evealteoud s i fw e
couljdu sgte ta glimposfet hastp acoef p ossibblieo logies.
Jusats c hemisdtirdny o tb ecomlea wfuuln ttihles eotf c ompounudnsd esrt udwya s
extendbeedy ontdh es eotr iginparlolvyi dbeydn atures,o i ti sl iketlhya bti olowgiyl l
notb ecomel awfulu ntitlh es eto fb iologiecntailt uinedse srtu dyi sv astelxyt ended
beyontdh es eotr iginparlolvyi dteodu sb yn atureT.h iiss t her oloef s yntheasnids ,
thiisst hep rimamroyt ivatfiootrnh efi elodf Art ificiaLli fteo:g ivues a glimposfet hat
widesrp acoef p ossibblieo logies.
Noto nlyd idt hes ynthemteitch oidn c hemistryl eatdo a mores olitdh eoretical
groundionfgt hefi eldi tsebluftt, h ev ernya turoefs ynthelseidts o n oveclh emical
compoundwsi tmha nyp ractiicnadlu starnidae ln gineeraipnpgl icatsiuocnhas s,s yn­
thetirucb berp,l astmiecdsi,c icnoamlp oundasn,ds of ortLhi.k ewiasm ea,j omro tivation
fort hefi elodf Artifi cial Lifbee,s idtehsed esifroera firmetrh eoretgircoauln difnogr
biologiyst, h ep romisieth oldfso rt hes yntheosfib si ologipchaeln omenianf orms
thawti lble o fg reaptr actiucsaeil n o uri ndustarnidae ln gineereinndge avoNrast.u re
hasd iscoveirnegde nisooulsu titoomn asn yh aredn gineerpirnogb lempsr,o bletmhsa t
we haven otb eena blteo s olvbey o urt raditieonngailn eermientgh odTsh.e s ynthetic
proceosfsa ttempttiorn egc retahtees bei ologsioclault iionon tsh emra teriwaillbsle o f
great praucsteFi.uc ratlh ermwoer mea,y e venb orrotwh ee ngineermientgh od nature
usedt oc omeu pw itthh esien genisooulsu tiiontn hsefi rsptl acteh:ep rocess of evolu­
tionB.ys ynthesitzhimene gc hanisumnsd erlytihneeg v olutiopnraorcyei sncs o mputers
andi no the"rn onbiolomgeidciaalw,"e c and iscovseorl utitooen nsg ineerpirnogb lems
thahta vel onrge sisotuertd r aditiaopnparlo aches.
Howevears,w ast hec aswei tshy nthecthiecm istwrey n,e edn otr estrict otuor selves
attemptmienrge ly to rbeicorleoagtpiehc eanlo mentah aotr iginoaclcluyr rneadt urally.
We haveth e entisrpea coef p ossibblieo logisctarlu ctuarnedsp rocestsoee sx plore,
includtihnogst eh ante vedri de volhveer oen e arthT.h usArt,i ficiLailf nee edn otm erely
attemtport ecrenaattuer aes i ti sb,u ti sf reteoe xplonraet uarsei tc oulhda vbee en-as
itc oulsdt ibleli fw e realiazrtifieC ialwlhya td idn oto ccunra turalOlfyc .o urswee,
mustc onstanbteal wya roef w hicohf o ure ndeavoarrser elevtaonb ti oloagnyd,w hich
breagkr ountdh aitsu ltimaotuetlsyi odfte h ed omaionf b iologrieclaelv anHcoyw.e ver,
mucho fth e lattweirlb le o fi nteroensi tt osw nr ighrte,g ardloefws hse theorrn oti t
teachuessa nythianbgo ubti oloagsyi ti su ndersttooodda yArtifi.c ial Lifwei ltle ach
gy
usm ucha boubti olo-mucht hawte c oulndo th avel earnbeyds tudyitnhgen atural
producotsfb ioloaglyo ne-bArtifiucti al Lifwei lull timarteealcybh e yonbdi oloignyt,o
a realtmh awte don oty eth avea namef orb,u tw hicmhu sti nclucduel tuarnedo ur
technolionga yne xtendevdi ewo fn ature.
x
ChristoGp.hL earn gton EditoIrn'tsro duction
Id on'wta ntm ereltyop ainat r ospyi ctuorfte h efu turoef Artifi cial lifIet.w ilnlo t
solvaelo lf o urp roblemIsn.d eeidtm, a yw elald dt ot hemTh.e potenttihaaArtifiltc ial
lifheo ldfso urn locktihnegs ecreotsfl ifiesg reabtu,ti nu nlocktihnogs see crewtesru n
ther isokfu nlockaiP nagn dorab'osx As. hasb eenth ec aswei tho urm asteoryf a nyn ew
technoliontg hye p astth,e m asteoryf t het echnoloofgl yi fheo ldtsr emendous potential
fobre neficuisaelb, u ti ta lshoo ldtsr emendopuost entfioaarlb usew,h ethaecrc idental
ori ntentiPoenrahla.tp hse s implewsatyt oe mphasitzheip so initsb ym erelpyo inting
outt haMta ry Shellepyr'osp hesttiocro yfD r.F rankensctaenni onl ongbeerc onsidered
tob em erelsyc ienficcet ioWne. a reo nt hev ergoefd uplicaDtri.Fn rga nkenstefiena'ts
andt,h erefoofrd eu,p licatthienc go nsequentcheaslt e atdo h isu ltimarutien .M ary
Shellegye'nsi uwsa st op aintth es cientist Fraanstk heern esatmleo inns toefrt hes tory,
byh isr efusatloa cceprte sponsifboirtl hietp yo tential consoefqh uiespn ucressuo ift
knowledfgoeri tosw ns akeT.h eries a lesshone rfeo ra lslc ienncoet,j usArtti ficial
lifbeu,t i ti se speciaploliyg nawnhte no nec onsidwehrast i ti st haArtifitc ial lifies
attemptitnoag c complish.
Artificiall ifwei lhla vea tremendoiumsp acotn t hefu turoef l ifoene arth asw elals
ono urv iewo fo urselvaensd t he" roloef"h umanb eingisnt heg reatoevre raslclh eme
oft heu niverIsnea .d dittioosn c ientifiacn dt echniicsaslu Arteifisc,i allif e raisemsa ny
questimoonrsea ppropritarteealtybe ytd h ed isciploifpn heisl osoapnhdye thicWsh.a t
ist heo ntologsitactaulos f a rtifiCialclreya t"eldi vienngt"i tiWehsa?t ridgoh tthse y
haveW?h ati st hen aturoeft her elationbsehtwiepe no urselavsec sr eataonrdso ur
artifaacstl si vicnrge atioHnosw? w ilArtifilc ial Lifiem pacsto cieHtoyw?, i fa ta llc,a n
we guarantee peaceful cwoiethxa iutsotneonmcoeu esvloyl visnygn theltifiefc o rms
sharionugrp hysiecnalv ironmeWnhta?ti st hefu turoef l ifnea,t uraanlda rtificial?
Obvioustlhyed, o maionfd iscoucrosnec ernArtifiicniga lL ifiesp otentivaelryll ayrg e,
involvviinrtuga llaylo lf t hea cademdiics cipliThisn esi.sq uitae d iverasree fao ra
singfileel dt oc oveir,n cludriensge aricnwh e twareh,a rdwarseo,ftw area,n dm ore.
Itis expecttehda tth e" breaadn db uttero"f t hefi eldw ilclo nsiisntc omputational
approac'hteoosp enp robleimnsb iologtihceaolrya ndi nt hea pplicaotfib oino logical
principtloee nsg ineerdionmga insH.o weverw,e cannoitg norteh ei mpactth aotu r
studiweisl hla veo n lifiet seolnf u,s a sl ivitnhgi ngosr,o n ouru nderstanodfi ng
ourselavnedso urp lacient heu niverse.
Thivso lumseh oulsde rvea sa ni nitoiraile ntattioto hne d ivertseer riotfoArtifi ryc ial
Lifree searbcuhti, t i so nlay crudem app iecetdo gethtehrr outghhe e ffortosft hese
earleyx ploreThresr.ei sm uchm oret ob ed iscovearneddt ,h eriesm uchm oret ob e
learneevde na boutth et erritroerviieesw heedr eM.y hopei st hatth iesa rlmya pw ill
inspiorteh etrosfu rtheerx plorations.
xi