0.05mya(Pleistocene-glacia4ons)

Earth’sTectonicHistory

542

488

444

416

359

299

251

200

146

65

1.8

h;p://jan.ucc.nau.edu/~rcb7/globaltext2.html

Cambrian Devonian CarboniferousSilurianOrdovician Permian Triassic Jurassic Cretaceous TerQary

Paleozoic Mesozoic Cenozoic

Phanerozoic

mya

CANADASIBERIA

AUSTRALIA

CHINA

EUROPE

ZoogeographicConsequences

2

1)  ShiFingPaGernofIsola4onandConnectednessTheseparaQonofconQnentsprovidedopportuniQesforallopatryonagrandscale

(figurefromFlessa1980)

Recalltheimportanceofisola1onindiversifica1onviaallopatricspecia1onThisstudycomparesthesimilarityin(mammal)speciescomposiQonbetweenpairsoflandmasses(eachpointisapairedcomparison)VersusthedistancethatseparatesthoselandmassesineachpairLandmassesinclude:NA,SA,Africa,Eurasia,NewGuinea,MadagascarandAustralia(A)

(thedistancealongtheroutethatminimizesoverwatertravel)

Similarity(%

)

ZoogeographicConsequences

3

1)  ShiFingPaGernofIsola4onandConnectedness

1)MammalbioQcsimilaritydecreasesasoverlanddistancebetweenlandmassesincreases2)MostpairwisecomparisonswithAustralia(A)fallbelowtrendline(moredisQnctduetolongisolaQonofAustralianconQnent)

(thedistancealongtheroutethatminimizesoverwatertravel)(figurefromFlessa1980)

Similarity(%

)

ZoogeographicConsequences

4

1)  ShiFingPaGernofIsola4onandConnectedness

(figurefromFlessa1980)

18mya

Similarityinmarineinvertebrate(fossil)composiQondecreasesasdistancebetweenwesternandeasternAtlanQcbasinsincreasesoverQmeAsmid-AtlanQcridgepushedconQnentalplatesapart,AtlanQcOceanformedandgotbiggerIncreasingisolaQonofmarineinvertebratefaunasoneithersideofridgewithopportunityfordivergenceJ=Jurassic;K=CretaceousP=Paleogene;N=Neogene

Similarity(%

)

185mya

ZoogeographicConsequences

5

1)ShiFingPaGernofIsola4onandConnectedness

Bio4cExchanges

(fromVermeij1991)

6

GreatAmericanBio4cExchangeTimelineofEvents:220-160mya:NandSAmericapartofGondwanaland.Origin,diversificaQonandspreadofmammalsandbirds.140mya:IsolaQonofSAmerica.65mya:NandSAmericaapproachingpresentconfiguraQon.MajorexQncQons(includingdinosaurs).MeteorimpactatChicxulub(GulfofMexico).3.5mya:EmergenceofCentralAmericanlandbridge.2.5-0.012mya:LoweringsealevelsandextensionofsavannabiomeinCentralAmericaduringglacialmaxima.MajorbioQcexchangesbetweenN.andS.America.

Pleistocen

eCretaceo

us

Jurassic

TerQary

ZoogeographicConsequences1)ShiFingPaGernofIsola4onandConnectedness

7

MammalsofNandSAmericabeforeexchange:

PrimatesOctodontsSpinyratsNutriasAgouQsCapybarasCaviesThree-toesslothsTwo-toedslothsAnteatersShrewopossums

PorcupinesGlyptodontsArmadillosGiantgroundslothsOpossums

ShrewsPocketmicePocketgophersBeaversPronghornsBison

RabbitsFieldmiceFoxesBearsRaccoonsWeaselsCats

MastodonsHorsesTapirsPeccariesCamelsDeer

ZoogeographicConsequences1)ShiFingPaGernofIsola4onandConnectedness

8

PrimatesOctodontsSpinyratsNutriasAgouQsCapybarasCaviesThree-toesslothsTwo-toedslothsAnteatersShrewopossums

PorcupinesGlyptodontsArmadillosGiantgroundslothsOpossums

ZoogeographicConsequences

ExchangeofMammalsofNandSAmerica:

ShrewsPocketmicePocketgophersBeaversPronghornsBison

RabbitsFieldmiceFoxesBearsRaccoonsWeaselsCats

MastodonsHorsesTapirsPeccariesCamelsDeer

1)ShiFingPaGernofIsola4onandConnectedness

9

Reasonsforasymmetricbio4cexchange:1.  NAmericanmammalswerebe;ermigrators

couldbeduetothefactthatthereweremoresavannaspecialistsinNAmerica,andconQnuoussavannathroughthelandbridge.

2.  Theywerebe;ersurvivorsSAmericanmammalstendedtobeclosed-forestspecialists,andforesthabitatbecamefragmentedwithclimatechange(smallerpopulaQons,moreexQncQon).

3.  Theywerebe;ercompeQtors(?)maybeNoclearreasonfordifferenQalsuccess.

ZoogeographicConsequences1)ShiFingPaGernofIsola4onandConnectedness

10

ExchangeofBirdsofNandSAmerica:

HummingbirdsTyrantflycatchersVireosWoodwarblersBlackbirdsOriolesTanagersEmberizinebunQngs

PigeonsOwlsWoodpeckersJays

ZoogeographicConsequences1)ShiFingPaGernofIsola4onandConnectedness

11

OtherVertebratesofNandSAmerica:Someshowopposingpa;erns,butalmostalwayswithunbalancedexchange.

ZoogeographicConsequences1)ShiFingPaGernofIsola4onandConnectedness

ZoogeographicConsequences

12

2)ChangingAmountsofLandandSeaArea

TheproporQonoflandmassatdifferentlaQtudeshasnearlyreversedsince425myafromsouthoftheequator(linedarea)tonorth(beigeplainarea)Whenlandmassesdrinedoverthepoles,theytriggeredcyclesofglaciaQonandchangesinsealevel

ZoogeographicConsequences

13

2)ChangingAmountsofLandandSeaArea

DiversityofammonitesClassCephalopodaSpiralshapedfossilizedshellsIndexfossils–canbeusedtolinktherocklayerinwhichtheyarefoundtospecificgeologicalQmeperiodsExQncQoneventsinthemarinerealmcanbelinkedtochangesinsealevel,whichalteredtheareaofconQnentscoveredbyshallowseas

ZoogeographicConsequences

14

3)ClimateChange

FollowingbreakupofAustraliaandAntarcQca,thesouthernmarginsofAustraliawereexposedtocoolcurrentsCooldryairmassesalongsouthernmarginsofAustraliawerelikelyamajordrivingforcegeneraQngthegreatcentraldeserts

ThebreakupofPanaeapromotedcircum-equatorialTethyanseawaycurrent

ZoogeographicConsequences

15

3)ClimateChange

Dropinnumberoffamilies(exQncQon)aroundQmeofPangaeaformaQon(betweenPermain“P”andTriassic“TR”Periods

Rapidincreaseinnumberoffamilies(diversificaQon)anerbeginningofPangaeabreakupintheJurassicPeriod“J”

ZoogeographicConsequences

16

4)HydrothermalVentsandTectonically-DerivedFaunasHightemperatureenvironmentswithhighhydrogensulfideconcentraQonaroundridgesofseafloorspreadingDiscoveryin1977ofwholedeepwatercommuniQes(>6000mdeep)basedonchemosynthesisHighlydisQnctbecause:

1.  veryisolated2.  veryold(originatedover400mya)3.  highlyspecializedadaptaQons

DiscoveryresultedinrecogniQonofanewphylum:VesQmenQfera,with14families,and>50genera(includeshighlyunusualtubeworms)

ZoogeographicConsequences

17

4)HydrothermalVentsandTectonically-DerivedFaunas

ColorcirclesshowventswithsimilaranimalcommuniQes(fromh;p://www.csa.com/discoveryguides/vent/review5.php#n1)

ConQnentalDrinReferencesforthissec4on:Flessa,K.W.1980.BiologicaleffectsofplatetectonicsandconQnentaldrin.Bioscience30:518-523.

Lomolino,M.V.,B.R.Riddle,R.J.Whi;aker,&J.A.Brown.2010.Biogeography(4thed.,Chapter2).SinauerAssociates,Inc.,Sunderland,Mass.

USGSwebsiteonplatetectonics:h;p://pubs.usgs.gov/gip/dynamic/dynamic.html

18

InteresQngquesQonswithplatetectonics…

1)  Dootherplanetshaveplatetectonics?Foryears,manyscienQstshadthoughtthatplatetectonicsexistednowhereinoursolarsystembutonEarth.In2012,aUCLAscienQsthasdiscoveredthatthegeologicalphenomenon,whichinvolvesthemovementofhugecrustalplatesbeneathaplanet'ssurface,alsoexistsonMarsMarsisataprimiQvestageofplatetectonics.ItgivesusaglimpseofhowtheearlyEarthmayhavelookedandmayhelpusunderstandhowplatetectonicsbeganonEarth

2)WhatwillourconQnentslooklike250millionyearsfromnow?h;ps://www.youtube.com/watch?v=uLahVJNnoZ4

InteresQngquesQonswithplatetectonics…