2003.V Smith.Chico
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Transcript of 2003.V Smith.Chico
Coevolution
Session 1fEvolution Meetings – Chico 2003
Ancient Mariners & Recent Stowaways:the coevolution of seabirds & their lice
Division of Environmental and Evolutionary BiologyInstitute of Biomedical and Life Sciences
Graham Kerr BuildingUniversity of Glasgow
Scotland
Vincent S. Smith & Roderic D.M. Page
Parasites… ancient associatesor recent acquisitions?
time
Cospeciation
Extinction
In situ radiation
Serial colonisation
Recent colonisation
Diversification byhost switching
HostParasite
Time isimportant!
The Hosts & Parasites
Feather lice(Insecta: Phthiraptera)
Tubenose seabirds(Aves: Procellariiformes)
Tubenose seabirds are very lousy!
Ischnocera
Charadriiformes
ProcellariiformesN
umbe
r of l
ouse
spe
cies
Procellariif
ormes
Charadriiform
es0
1
2
3
4
5
6Ischnocera
Analysis
ii. Rates smoothing• nonparametric rate smoothing using r8s (Sanderson, 2003)• perform on 100 trees drawn from Bayesian chain
iii. Calibration• assume that cospeciating host/parasites are likely to be the same age• penalised likelihood to estimate the relative age of the other nodes
i. Host/parasite phylogenies• mitochondrial 12s rRNA, COI & Cyt. B• Bayesian analysis (trees sampled every 1000 generations after ‘burnin’)
Albatross-louse cophylogeny
0.01
Macronectes giganteus
Diomedea epomophora
Diomedea exulans
Diomedea gibsoni
Diomedea antipodensis
Phoebastria nigripes
Phoebastria irrorata
Thalassarche chrysostoma
Thalassarche melanophris
Thalassarche cauta
Thalassarche bulleri
Phoebetria palpebrata
0.1
Paraclisis obscura
Paraclisis hyalina NZ AP16
Paraclisis hyalina FD03
Paraclisis hyal ina GLA901
Paraclisis hyal ina GLA896
Paraclisis confidens
Paraclisis miriceps
Paraclisis d iomedeae FD07
Paraclisis d iomedeae FD10
Paraclisis diomedeae GLA529
Paraclisis diomedeae NZ AP21
Paraclisis d iomedeae FD05
Hosts:Albatrosses
Parasites:Feather Lice
Page et al (in press)Mol. Phyl. Evol.
Analysis
v. Tree mapping• identify comparable nodes in the host & parasite tree• compare ages of nodes
ii. Rates smoothing• nonparametric rate smoothing using r8s (Sanderson, 2003)• perform on 100 trees drawn from Bayesian chain
iii. Calibration• assume that cospeciating host/parasites are likely to be the same age• penalised likelihood to estimate the relative age of the other nodes
iv. Sensitivity analyses• rate smoothing is sensitive to choice of smoothing parameter• we varied the log of the parameter for each of the 100 bird/louse trees
i. Host/parasite phylogenies• mitochondrial 12s rRNA, COI & Cyt. B• Bayesian analysis (trees sampled every 1000 generations after ‘burnin’)
Procellariiform-louse tanglegram
0.1 substitu tions per s ite
Thalassarche bulleri
Phoebastria nigripes
Diomedea exulans
1.00
1.00
1.00
Pelagodroma marina
0.60
Macronectes giganteus
Daption capense
1.00
Puffinus gravis
Puffinus griseus
1.00
Puffinus pacificus
1.00
Puffinus huttoni
0.96
Calonectris diomedea
1.00
Procellaria westlandica
1.00
Pelecanoides georgicus
Lugensa brevirostris
Pachypt ila vittata
Pachyptila turtur
1.000.60
0.94
0.33
Pterodroma inexpectata
Pterodroma cooki
1.00
0.44
1.00
0.95
Paraclisis diomedeae
Paraclisis conf idens
Paraclisis hyalina
Paraclisis hyalina
1.00
Paraclisis obscura1.00
1.00
0.99
Perineus concinnoides
Harrisoniella hopkinsi
1.00
0.77
Pelmatocendra enderleini
0.35
Halipeurus pelagicus
Halipeurus diversus
Halipeurus gravis
Halipeurus spadix0.82
Halipeurus abnormis
Halipeurus consimilis
1.00
0.99
0.73
0.98
0.70
Naubates harrisoni
Naubates fuliginosus 1.00
1.00
Pseudonirmus gurlt i
1.00
Naubates pterodromi 0.69
0.30
0.18
Bedfordiella unica
1.00
0.1 s ubs ti tu tions per s ite
Diomedea epomophora
Halipeurus turtur
Naubates prioni
Naubates prioni
0.67
Bayesian inference(12s rRNA, COI & Cyt. B)
Are procellariformlice as old as their hosts?
• Age estimates relatively constant across arange of smoothing parameters
• Radiation of procellariform lice is slightlymore recent than that of their hosts
log 10 smoothing
3
2.5
2
1.5
1
0.5
0
0 0.5 1 1.5 2.52 3
Procellariiformes
rela
tive
age
Procellariform birds 2-2.5 timesolder than albatrosses
0
3
2.5
2
1.5
1
0.5
0 0.5 1 1.5 2.52 3
Feather lice
log 10 smoothing
rela
tive
age
Feather lice 1.75-2.25 timesolder than albatross lice
Bird-Louse Ages
T halas sarche buller i
P hoebas tria n igripes
Diomedea ex ulans
Diomedea epomophor a
Pelagodroma mar ina
Macr onectes giganteus
Daption capense
Pelecanoides georgicus
Lugensa brevir os tris
Pachyptila v itta ta
Pachyptila turtur
Pterodr oma inex pectata
Pterodr oma cook i
Py gosc el is adeliae
Eudyptula m inor
Gavia arctica
Gavia immer
Puffinus griseus
Puffinus grav is
Puffinus hutton i
Calonectris d iomedea
Procel laria westlandica
Thalass arche bulleri
P hoebastria n igripes
Diomedea exulans
Diomedea epomophora
Pelagodroma marina
Macr onectes giganteus
Daption capense
Pelecanoides geor gicus
Lugensa brevir os tr is
Pachyptila vitta ta
Pachyptila turtur
Pterodroma inex pec tata
Pterodroma cook i
Py gosc el is adeliae
Eudyptu la m inor
Gavia arctica
Gavia immer
Parac lisis d iomedeae
Paraclisis confidens
Paraclisis hyalina
Par ac lisis hy al ina
Paracl isis obs cura
Naubates harr isoni
Naubates fu liginos us
Puffinus gr iseus
Puffinus gr av is
Puffinus hutton i
Calonectris d iomedea
Procellaria wes tlandica
Halipeurus pelagicus
Hal ipeurus diversus
Hal ipeurus gravis
Halipeurus spadix
Halipeurus abnorm is
Hal ipeur us c onsimi l is
Hal ipeurus turturi
Naubates prioni
Naubates prion i
Naubates pterodromi
Perineus concinnoides
Harr isonie l la hopkins i
relative age relative age123 0 0 1 2 0 1 2
• How do we accountfor this?
?
Relative Age of Host-Parasite Clades
0
0.5
1
1.5
2
2.5
0 0.5 1 1.5 2 2.5
Host Age
Lous
e A
gePetrels & Halipeurus
Procellariformes &Philoceanus-complex
• Lice ¾ of the ageof their hosts!
• i.e lice are slightlyyounger than wemight expect if theyare “cospeciating”
Conclusions
i. Is this discrepancy real?• Are the assumptions behind the calibration point correct
Calibration Correction?Hosts:Albatrosses
Parasites:Feather Lice
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0.02 0.04 0.06 0.08 0.1 0.12
Host divergence
Lous
e di
verg
ence Delayed
cospeciation
i.e. Paraclisisspeciating slightlyafter their hosts
Conclusions
iii. Do we need to redefine “cospeciation”• Is the expectation of temporal congruence always correct in
cospeciating lineages?
i. Is this discrepancy real?• Are the assumptions behind the calibration point correct
ii. If it is real, what does it mean?• Gene flow briefly persists between lice after speciation of the host?• Failure of lice to speciate (Johnson et al, 2003)• Aren’t we really dating gene coalescent times anyway?
(Rannala & Michalakis, 2002)
Acknowledgements
• Martyn Kennedy & Rob Cruickshank
• Wellcome Trust