Adaptive Radiations Ecology Biogeography Genetics

Adaptive RadiationsAdaptive Radiations

. . . . . . Systematics Systematics meets Ecology . . .meets Ecology . . .

Future of MolecularFuture of Molecular Systematics Systematics

1.1. BiogeographyBiogeography

2.2. EcologyEcology

3.3. GenomicsGenomics PhylogenyPhylogeny

DevelopmentDevelopment

GeneticsGenetics

TaxonomyTaxonomy

CytologyCytology

EcologyEcology

BiogeographyBiogeography

MorphologyMorphology

Ecology and phylogeneticsEcology and phylogeneticsintertwinedintertwined when looking at when looking atthe emergence of life formsthe emergence of life formson earth and theiron earth and theirsubsequent diversificationsubsequent diversification

Emergence of Life FormsEmergence of Life Forms

•• emergence of emergence of 3 domains3 domains of oflife with life with 6+ kingdoms6+ kingdoms


•• rise of major lineages of rise of major lineages ofeukaryotaeukaryota - many of which we - many of which wedo not yet know how relateddo not yet know how related

Emergence of Life FormsEmergence of Life Forms•• movement of movement of plants onto landplants onto landand their subsequentand their subsequentdiversificationdiversification

Ordovician-DevonianOrdovician-Devonian


•• and finally the and finally the rise and domination of flowering plantsrise and domination of flowering plants


Emergence of flowering plants has two important facets:Emergence of flowering plants has two important facets:

1.1. RadiationRadiation - large number of species resulted - large number of species resulted

2.2. AdaptiveAdaptive - exploited incredible array of - exploited incredible array ofecological strategies or nichesecological strategies or niches


•• in 130 my angiosperms dominate in 130 my angiosperms dominatebiomesbiomes from tropical forests to arctic from tropical forests to arctictundra . . .tundra . . .

Adaptive RadiationsAdaptive Radiations•• . . . . . . rainfallrainfallgradientsgradients from the from thewettest to the mostwettest to the mostarid habitats onarid habitats onearth . . .earth . . .

Adaptive RadiationsAdaptive Radiations•• . . . . . . life formslife forms from giant emergent from giant emergenttropical trees to the tiniest aquatictropical trees to the tiniest aquaticduckweeds . . .duckweeds . . .

Adaptive RadiationsAdaptive Radiations•• . . . and . . . and exploited reproductive biologyexploited reproductive biology in elaborate outcrossing in elaborate outcrossingand seed dispersal methods to forgoing sex altogether via apomixisand seed dispersal methods to forgoing sex altogether via apomixisand parthenogenesisand parthenogenesis

Adaptive RadiationsAdaptive Radiations•• Angiosperms show all necessary Angiosperms show all necessarycharacteristics of an characteristics of an adapativeadapativeradiationradiation

•• Key innovation Key innovation spurring this spurring thisadaptive radiation?adaptive radiation?

flowers?flowers? triaperturate pollen?triaperturate pollen?vessels?vessels?

Variation in Lineage DiversityVariation in Lineage DiversityVariation in lineage diversity relates to the appearance of Variation in lineage diversity relates to the appearance of unequalunequalnumbers of species in sister lineagesnumbers of species in sister lineages

Besides some uniqueBesides some uniqueexceptions, the expectationexceptions, the expectationis that is that sister lineagessister lineagesshould show roughly equalshould show roughly equalnumbers of species numbers of species - as- asthey are equal in agethey are equal in age

What are the exceptions?What are the exceptions?


1.1. Differential extinction Differential extinction

One lineage (One lineage (clade 1clade 1) is) ismore diverse simplymore diverse simplybecause the other wasbecause the other wasmaladapted perhaps to amaladapted perhaps to achanging environmentchanging environment

Variation in Lineage DiversityVariation in Lineage DiversityDifferential extinction is well known inDifferential extinction is well known inthe fossil record:the fossil record:

6 great extinction events6 great extinction eventsPleistocenePleistocenemegafaunamegafauna

Variation in Lineage DiversityVariation in Lineage DiversityDifferential extinction is well known inDifferential extinction is well known inthe fossil record:the fossil record:

Diverse lycopods & horsetails in CarboniferousDiverse lycopods & horsetails in Carboniferous


2. Coevolution2. Coevolution

One lineage (One lineage (clade 2clade 2) is) ismore diverse because ofmore diverse because ofthe ability to co-evolve withthe ability to co-evolve withother organismsother organisms

Variation in Lineage DiversityVariation in Lineage DiversityFlowering plants show remarkable abilityFlowering plants show remarkable abilityto co-evolve with other organisms:to co-evolve with other organisms: PollinationPollination

Variation in Lineage DiversityVariation in Lineage DiversityFlowering plants show remarkable abilityFlowering plants show remarkable abilityto co-evolve with other organisms:to co-evolve with other organisms:

Chemical armChemical arm’’s races race

PhyllobroticaPhyllobrotica

ScutellariaScutellaria


3. Adaptive radiation3. Adaptive radiation

One lineage (One lineage (clade 2clade 2) is) ismore diverse due tomore diverse due tocombination of speciescombination of speciesradiation and adaptationradiation and adaptationinto many ecological zonesinto many ecological zonesperhaps due to the origin ofperhaps due to the origin ofa novel featurea novel feature

Adaptive RadiationsAdaptive Radiations““. . . species occasionally arriving after long intervals in a new and. . . species occasionally arriving after long intervals in a new andisolatedisolated district, and having to district, and having to competecompete with new associates, will with new associates, willbe eminently liable to be eminently liable to modificationmodification, and will often produce groups, and will often produce groupsof of modified descendantsmodified descendants”” [Darwin, 1853] [Darwin, 1853]

Adaptive RadiationsAdaptive Radiations““. . . an isolated region, if large and sufficiently varied in its. . . an isolated region, if large and sufficiently varied in itstopography, soil, climate and vegetation, will give rise to atopography, soil, climate and vegetation, will give rise to adiversified fauna according to the diversified fauna according to the law of adaptive radiationlaw of adaptive radiation from fromprimitive and central types. Branches will spring off in allprimitive and central types. Branches will spring off in alldirections to take advantage of every possible opportunity ofdirections to take advantage of every possible opportunity ofsecuring food.securing food.”” [Osborn, 1900] [Osborn, 1900]

First use of termFirst use of termadaptive radiationadaptive radiation

““. . . an . . . an isolatedisolated region, if large and region, if large and sufficiently variedsufficiently varied in its in itstopography, soil, climate and vegetation, will give rise to atopography, soil, climate and vegetation, will give rise to adiversified faunadiversified fauna according to the according to the law of adaptive radiationlaw of adaptive radiation from fromprimitive and central types. primitive and central types. Branches will spring offBranches will spring off in all in alldirections to take advantage of directions to take advantage of every possible opportunity ofevery possible opportunity ofsecuring foodsecuring food..”” [Osborn, 1902] [Osborn, 1902]

Adaptive RadiationsAdaptive Radiations““. . . adaptive radiation strictly speaking refers to more or less. . . adaptive radiation strictly speaking refers to more or lesssimultaneous divergence of numerous linessimultaneous divergence of numerous lines all from much the all from much thesame ancestral adaptive type same ancestral adaptive type into different, also diverginginto different, also divergingadaptive zonesadaptive zones..”” [Simpson, 1953] [Simpson, 1953]

Issues in Adaptive RadiationsIssues in Adaptive Radiations•• It is clear that It is clear that fewfew of the classic cases of adaptive radiation of the classic cases of adaptive radiationhave been have been studied rigorously from a combined systematic andstudied rigorously from a combined systematic andecological point of viewecological point of view

Two main issues:Two main issues:

Issues in Adaptive RadiationsIssues in Adaptive Radiations1.1. The very characters whose diversification is being examined The very characters whose diversification is being examined(e.g. beak size, shape, function in Darwin(e.g. beak size, shape, function in Darwin’’s finches), can also bes finches), can also beused to determine relationships and classify the organismsused to determine relationships and classify the organismspossessing them - possessing them - potentially circularpotentially circular!!

Issues in Adaptive RadiationsIssues in Adaptive Radiations2.2. Extreme convergence and divergence is likely in groups that Extreme convergence and divergence is likely in groups thatare undergoing adaptive radiationsare undergoing adaptive radiations

DivergenceDivergence: changes in homologous structures: changes in homologous structuresamong related species; among related species; changes permit eachchanges permit eachspecies to specialize in species to specialize in different environmentsdifferent environments

ConvergenceConvergence: changes in analogous structures: changes in analogous structuresamong unrelated species; among unrelated species; changes permit eachchanges permit eachspecies to specialize in the species to specialize in the same environmentsame environment

Issues in Adaptive RadiationsIssues in Adaptive RadiationsThese two issues in studying adaptive radiations are bestThese two issues in studying adaptive radiations are bestaddressed by using an addressed by using an independentindependent source of information - source of information -molecular phylogenetic charactersmolecular phylogenetic characters

PhylogenyPhylogeny

DevelopmentDevelopment

GeneticsGenetics

TaxonomyTaxonomy

CytologyCytology

EcologyEcology

BiogeographyBiogeography

MorphologyMorphology

Adaptive RadiationsAdaptive RadiationsIllustration of these problems with 3 examples of adaptiveIllustration of these problems with 3 examples of adaptiveradiationradiation

Rift Valley CichlidsRift Valley CichlidsCichlids possess a double jaw system, the Cichlids possess a double jaw system, the pharyngeal jawpharyngeal jaw is isthought to be a key innovation for species proliferation andthought to be a key innovation for species proliferation anddivergence in feeding strategiesdivergence in feeding strategies

Lake TanganyikaLake Tanganyika Lake MalawiLake Malawi

•• species with similar species with similar feedingfeedingstrategiesstrategies between lakes related?between lakes related?•• species showing different feeding species showing different feedingstrategiesstrategies within a lake related?within a lake related?

Rift Valley CichlidsRift Valley CichlidsCichlids possess a double jaw system, the Cichlids possess a double jaw system, the pharyngeal jawpharyngeal jaw is isthought to be a key innovation for species proliferation andthought to be a key innovation for species proliferation anddivergence in feeding strategiesdivergence in feeding strategies

Lake TanganyikaLake Tanganyika Lake MalawiLake Malawi

•• divergence divergence within each lakewithin each lake!!

mtDNA treemtDNA tree

•• convergence convergence between lakes!between lakes!

Salvia Staminal LeverSalvia Staminal LeverThe giant genus The giant genus SalviaSalvia (Lamiaceae) possesses two stamens with (Lamiaceae) possesses two stamens withelongated connective tissueelongated connective tissue

Salvia Staminal LeverSalvia Staminal LeverPosterior thecae abort, fuse, and can form a Posterior thecae abort, fuse, and can form a lever devicelever device

pp

aa

SalviaSalvia4 stamens4 stamens 2 stamens2 stamens connectivesconnectives

Salvia Staminal LeverSalvia Staminal LeverThe resulting The resulting staminal leverstaminal lever has been regarded as a has been regarded as a keykeyinnovationinnovation for the species diversification in for the species diversification in SalviaSalvia via viapollination shiftspollination shifts

What does molecular What does molecular phylogeneticsphylogenetics indicate? indicate?

Jay Walker _ UW GradJay Walker _ UW Grad

Salvia Staminal LeverSalvia Staminal Lever•• SalviaSalvia is polyphyletic is polyphyletic with 3 with 3separate lineages of separate lineages of ““SalviaSalvia””each sister to other generaeach sister to other generawithout elongated connectivewithout elongated connective

•• lever mechanism lever mechanism correlatedcorrelatedwith significant specieswith significant speciesdiversification each time itdiversification each time itevolved relative to sisterevolved relative to sisterlineages - lineages - key innovation!key innovation!

250 spp.250 spp.

500 spp.500 spp.

90 spp.90 spp.

•• lever mechanismlever mechanism evolved evolvedconvergently 3 timesconvergently 3 times

lever mechanismlever mechanism

Hawaiian Island RadiationsHawaiian Island RadiationsIsolated, oceanic islands provide some of the most classic examplesIsolated, oceanic islands provide some of the most classic examplesof adaptive radiationof adaptive radiation

•• isolationisolation - once you - once youget there, you canget there, you can’’ttgo go backback

•• great ecologicalgreat ecologicaldiversitydiversity - many - manyniches to exploitniches to exploit2 volcanic2 volcanic

ridgesridges

NE trade windsNE trade winds

•• low diversity low diversity - -many niches openmany niches open

•• low competition,low competition,predation, predation, herbivoryherbivory- you can be- you can bedifferentdifferent


•• archipelago is archipelago is aaseries of series of geologicallygeologicallydateddated islands islands•• fixed fixed volcanicvolcanichotspot hotspot but Pacificbut Pacificplate plate conveyor beltconveyor belt


•• older to younger older to youngerislands allow forislands allow fordispersaldispersalbiogeographicalbiogeographicalanalysisanalysis

Hawaiian Island RadiationsHawaiian Island RadiationsBest studied group is the Best studied group is the Hawaiian silverswordHawaiian silversword complex complex

Phylogenetics, cytology,Phylogenetics, cytology,biogeography, ecology,biogeography, ecology,physiology, hybridization,physiology, hybridization,evolutionevolution

SilverswordsSilverswords

N

Kauai-11 endemic

Oahu-2 endemic

Maui Nui-7 endemic

Hawaii-3 endemic

Wilkesia gymnoxiphiumDubautia paleata Argyroxiphium

sandwicense

Plus 5 indigenous species

Tarweed (California USA) OGDubautia paleata KauaiKauaiDubautia waialealae KauaiKauaiDubautia laxa indigenousWilkesia gymnoxiphium KauaiKauaiWilkesia hobdyi KauaiKauaiArgyroxiphium caliginis MauiMauiArgyroxiphium grayanum MauiMauiArgyroxiphium virescens MauiMauiArgyroxiphium sanwicense MM&HHArgyroxiphium kauense HawaiiHawaii

Silversword Cladogram (simplified)Silversword Cladogram (simplified)

Hawaiian Island RadiationsHawaiian Island Radiations

oldestoldest

youngest islandyoungest island

5.2 mya5.2 myaestimateestimate

Hawaiian LobeliadsHawaiian LobeliadsWhy the Hawaiian lobeliads? Why the Hawaiian lobeliads?

•• largest group: largest group: 66genera, 115 species)genera, 115 species)•• 1/9th of native1/9th of nativefloraflora•• considered derived considered derivedfromfrom 3-5 separate 3-5 separatecolonizationscolonizations•• phenomenal phenomenalvariation in habitat,variation in habitat,life form, flowers,life form, flowers,and fruitsand fruits


•• appear to have appear to have co-co-evolvedevolved with the with theendemic Hawaiianendemic Hawaiianhoneycreepershoneycreepers


•• appear to have appear to have co-co-evolvedevolved with the with theendemic Hawaiianendemic Hawaiianhoneycreepershoneycreepers•• honeycreepershoneycreepersrepresent a separaterepresent a separateadaptive radiationadaptive radiation

Lobelia gloria-montisLobelia gloria-montis

Lobelia telekii - Lobelia telekii - Mt. KenyaMt. Kenya

Hawaiian LobeliadsHawaiian LobeliadsWhat are the Hawaiian lobeliads? What are the Hawaiian lobeliads?

BrighamiiBrighamii


DelissiaDelissia


TrematolobeliaTrematolobelia


ClermontiaClermontia


CyaneaCyanea


Hawaiian LobeliadsHawaiian LobeliadsThe Hawaiian lobeliads represent a The Hawaiian lobeliads represent a singlesingle (not 5) (not 5) lineage/colonization!lineage/colonization!

GivnishGivnish et al. 2009 et al. 2009

Hawaiian LobeliadsHawaiian LobeliadsThe Hawaiian The Hawaiian lobeliadslobeliads are an even more spectacular adaptive radiation are an even more spectacular adaptive radiation

Hawaiian LobeliadsHawaiian LobeliadsRemarkable divergent andRemarkable divergent andconvergent character evolutionconvergent character evolution- but - but fruit color is perfectlyfruit color is perfectlyconsistentconsistent with relationships with relationships

Hawaiian LobeliadsHawaiian LobeliadsTwo clock calibrations - usingTwo clock calibrations - usingAsterid fossils or usingAsterid fossils or usingHawaiian Island ages - place theHawaiian Island ages - place thedifferentiation of differentiation of HawaiianHawaiianlobeliads at 12-13 myalobeliads at 12-13 mya

Hawaiian Hawaiian LobeliadsLobeliadsTwo clock calibrations - usingTwo clock calibrations - usingAsteridAsterid fossils or using fossils or usingHawaiian Island ages - place theHawaiian Island ages - place thedifferentiation of differentiation of HawaiianHawaiianlobeliadslobeliads at 12-13 at 12-13 myamya

Original colonist arrived inOriginal colonist arrived inGardner PinnaclesGardner Pinnacles - large - largevolcanic islands 12-13 myavolcanic islands 12-13 mya

LobeliadsLobeliads are one of the oldest radiations of extant Hawaiian biota are one of the oldest radiations of extant Hawaiian biota –– but buttheir honeycreeper pollinators would not arrive for another 7-9 my their honeycreeper pollinators would not arrive for another 7-9 my (oh-oh!)(oh-oh!)

Hawaiian Hawaiian LobeliadsLobeliadsBut . . . a recent paper shows that the 5But . . . a recent paper shows that the 5recently extinct recently extinct Hawaiian Honeyeaters –– and andthought thought to be recently derived fromto be recently derived fromAustralAsian Honeyeaters –– are in fact 14-17 are in fact 14-17my old and derived from an American my old and derived from an American cladeclade - -waxwings, silky flycatchers, and palm chatswaxwings, silky flycatchers, and palm chats

Hawaiian Hawaiian lobeliadslobeliads13-14 13-14 myamya

Hawaiian HoneycreepersHawaiian Honeycreepers7 7 myamya

Fleischer et al. 2008Fleischer et al. 2008

Hawaiian Hawaiian LobeliadsLobeliads

•• Early Early lobeliadslobeliads had hadinitial radiation withinitial radiation withHawaiian honeyeatersHawaiian honeyeaters

•• later radiation of two later radiation of twolarge genera (large genera (CyaneaCyanea andandClermontiaClermontia) ) pimarilypimarily with withHawaiian honeycreepersHawaiian honeycreepers

Hawaiian Hawaiian LobeliadsLobeliads


. . . . . . Systematics Systematics meets Ecology . . .meets Ecology . . .

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Adaptive Radiations Ecology Biogeography Genetics