EEB#2244# Mutualism#&#Coevolution# Fall#2014#1##Mutualism)• Net#fitness#benefit#to#two#or#more#species#as#a#result#of#their#interaction#(+/+#interaction)#• Does#not#imply#a#costEfree#interactio n:#########Gain###########>##########Loss#Classifying#Mutualisms:#• Exchange#of#goods#or#provision#of#services#1.#Dispersiveà#trade #mo ve m en t#for#foo d##2.#Trophic#exchangesà#trade#one #reso urce #for#an oth er##(ba cteria #and #roo ts)##3.Defensiveà#guarding#in#return#for#food#or#service#• Intimac y#o f #th e #as s o cia tio n #1.#Consistent#spatial#and#temporal#association#2.Intermitt en tàinconsis te n t#a cro s s#s p ac e #an d #time#• Level#of#dependency#1.Facultativeà(option#to#take#p art#in#m u tua lism )#m u tua lism #is#no t#ess en tial#to#the #surv ival#of#o ne #or#either#species##2.#Obligateà#at#least#one#of#the#players#has#to#partake#in#mutualism#–#mutualism#required#for#the#survival#of#one#or#both#species#Examples#of#mutualisms#and#classifications:#• Generalist#plant/pollinators:##may#be#pollina t ed #b y #multiple#differe n t #sp e c ies#ESunflowers#&#butterflies/bees##Pollinators:#can#visit#multiple#species#of#plants,#all#that#matters#is#tha t#they #get#nu trition##• Specialist#plant/pollinators:#One#plant#a n d #o n e #p o llin a to r ,#re ly#o n#each#othe r#Plant:#Darwin’s#orchid#and#Morgan’s#sphinx#moth#à#can#be#highly#specialized###• Lichens:#Associa tio n #b e tween#fungi#a n d #p h otosynthes is#algae#Fungi#provides#physical#structure#for#water#retention,#photosymbionts#provide#nutrition##• Termites#with#protists#with#bacteria#Termits#consume#wood,#but#lack#necessary#digestive#enzymeà#protisits#in#gut#digest#celluloseàbacteria#live#in#prot ist s##Free#living#pop u la tio n s #of #th e #pr ot e st#t h at #ty pic a lly#liv e#in #t er m it e#g u ts #w e #w o u ld #cla s sify #Edigestive/defensive,#intermittent/intimate,#facultative#Coevolution)• Two#(or#more)#species#living####################in#clo s e#p ro x imity################################################################.##EEB#2244# Mutualism#&#Coevolution# Fall#2014#2###• Each#species#exerts#########################selection#pressure###########################################on#the#other(s)#and#vice#versa.##• Selection#pressure#results#in#changes#in######################gene#frequencies############################################(i.e.,#evolutionary#change)#of#all#interacting#species##Coevolution#Outcomes## 1.#ConsumerEResourceà#arms#race#between#predator#and#prey### 2.#Competitionà#Incre as e #in #co mpetitive#abilit y#o r #d ec re a se #in #n ic h e#o v e rla p #(redu ce#th e#amount#in#niche###take#up#or#increa se#in#nich e#se pa ration )## 3.#Mutualismà#positive#reinforcement##Coevolution#Outcomes:#ConsumerEResource#Interactions#• Adaptations#of#victims#or#prey,#both#in#response#to#each#other.##Can#manifest#as:## 1.#behavior## 2.morpholgy### 3.chemistry##• Adaptations#are#often#linked###• Adaptations#can#translate#into#nonEstatic#LotkaEVolterra#model#parameters#E Victims#adapt#to#avoid#getting#consumed#E>#results#in#lower#consumer#capture#rate######################################(c)#E Predators#adapt#to#better#capture#victims#E>#results#in#higher##consume r#capture#rate#################################################(#c#)##• Adaptations#can#translate#into#nonEstatic#LotkaEVolterra#model#parameters#E Victim#adapts#to#be#less#palatable/digestible#E>#results#in#lower####conversion#rate##########################################(a)#E Consumer#adapts#to#deal#with#victim#defense#E>#results#in#higher##########conversion#rate#########################################(#a##)##EEB#2244# Mutualism#&#Coevolution# Fall#2014#3##Coevolution#Outcomes:#ConsumerEResource#Interactions#• Increase d #c o m petitive#ability#####• Reduced#niche#overlap#Character#displacement:##character#traits#of#two#closely#related#species#differ########more##################when#they#are################sympatric####################################tha n#w he n#they#are######################allopatric##################################.#Coevolution#Outcomes:#Mutualism#•