Biogeography of Caribbean weevils highlights the importance of

founder-event speciation

Guanyang (GY) Zhang @GYZhang2Usmaan Barashat, Nick Matzke & Nico Franz Arizona State Universitytaxonbytes.org somanyinsects.org

Society for Systematic Biologists 2015 Standalone Meeting, Ann Arbor, Michigan 05/21/2015

© Carlos De Soto Molinari

Range-evolution processes

Model-based biogeographic inference methods (e.g., DEC, DIVA, BayArea) assume certain range-evolution processes.

Dispersal

ProcessBefore After

Ranges

Modified from Matzke (2013) Frontiers of Biogeography

A A

B B

A, B—area

Range-evolution processes

Model-based biogeographic inference methods (e.g., DEC, DIVA, BayArea) assume certain range-evolution processes.

Dispersal

ProcessBefore After

Ranges

Modified from Matzke (2013) Frontiers of Biogeography

Extinction

A A

A A

B B

B B

A, B—area

Range-evolution processes

Model-based biogeographic inference methods (e.g., DEC, DIVA, BayArea) assume certain range-evolution processes.

ProcessBefore After

Ranges

Modified from Matzke (2013) Frontiers of Biogeography

Range copying/Sympatry

A

A

A

Tree

A

A

A

A, B—area

Range-evolution processes

Model-based biogeographic inference methods (e.g., DEC, DIVA, BayArea) assume certain range-evolution processes.

ProcessBefore After

Ranges

Modified from Matzke (2013) Frontiers of Biogeography

Vicariance

A

B

ABB

B

BA

A

A

Tree

A, B—area

Founder-event speciation in geographic range evolution

Matzke (2014 Syst Biol) added founder-event speciation process into existing models of geographic range evolution.

Founder-event speciation/Jump dispersal (+J)

DEC—Dispersal-Extinction-Cladogenesis (Ree et al., 2005; Ree & Smith, 2008)DIVA—DIspersal-Vicariance Analysis (Ronquist, 1997)BayArea—Bayesian biogeographic analysis (Landis et al., 2013)

A A

B B

ProcessBefore After

Ranges Tree

A

B

A

Founder-event speciation in geographic range evolution

BioGeoBEARS implements several models, adds founder-event jump dispersal (J) and enables model selection.

Different biogeographic models (DIVA, DEC, BayArea, BioGeoBEARS supermodel) allow a certain set of biogeographic processes.

BioGeoBEARS specifies each process with a parameter that can be turned on or off, including “jump dispersal (j)”.

Matzke (2013) Frontiers of Biogeography

Processes ModelsBioGeoBEARS

Caribbean weevils in the Exophthalmus genus complex

High levels of diversity and single-island endemicity in the Caribbean.

Ideal for testing for founder-event speciation & studying Caribbean biogeography.

• Curculionidae: Entiminae (broad-noses)• Generalist plant-feeders• Larvae (aka caterpillar) live in soil

• Caribbean: ~85 species; >95% endemic• Central America: ~47 spp.• South America: ~12 spp.

E. nicaraguensis Bovie E. quadrivittatus (Olivier)

E. quinquedecimpunctatus (Olivier)E. roseipes (Chevrolat)

Images and specimen data @

Dated phylogeny

65 ingroup species, 26 outgroup.

Sampled major Greater Antillean islands, Lesser Antilles, and Central America.

6 genes, ~4800 bp. Phylogenetic reconstruction and

fossil-calibrated molecular dating with BEAST v1.8 . Three fossil calibration points

Objective 1 – Testing effects and fit of models with jump dispersal

What are the effects of modeling founder-event jump dispersal (J) on ancestral range evolution estimation? Most probable ancestral ranges were inferred to be a

single area.

DIVA+J DIVA (w/o J)Ancestral ranges as a single area Ancestral ranges widespread at some nodes

Objective 1 – Testing effects and fit of models with jump dispersal

What are the effects of modeling founder-event jump dispersal (J) on ancestral range evolution estimation? Most probable ancestral ranges were inferred to be a

single area. Jump dispersal accounted for virtually all range

evolution events.

DIVA+JDIVA+J

Dispersal

Sympatry(subset)

Vicariance

Vicariance

Vicariance

Extinction

A variety of range-evolution processes

Jumpdispersal

DIVA (w/o J)Only jump dispersal was inferred

Objective 1 – Testing effects and fit of models with jump dispersal

Do biogeographic models with founder-event jump dispersal (J) provide a better fit?

Model

Ln L

DIVALIKE -163.1 DIVALIKE+J -115.4

Likelihood-ratio test

AIC analysis

P weight ratio

1.5E-22 2.02E+20 Strong support from

statistical testsAdding jump dispersal led to much higher log likelihood

Objective 2 – Caribbean biogeography

Inter-island dispersal and within-area in situ diversification were the main drivers of speciation.

Jump dispersal occurred at 25% of all ancestral nodes (n=64), and range-copying (viz. in situ diversification) ~75%.

Cuba Cuba (in situ diversification)

25 MYA

Objective 2 – Caribbean biogeography

Neotropical mainland was colonized by Caribbean island species in the early Miocene (~18 MYA)

Caribbean Central America

Objective 2 – Caribbean biogeography

Current finding corroborates an emerging idea that islands can serve as a source for continental diversity.

Bellemain & Ricklefs (2008) TREE

Objective 2 – Caribbean biogeography

Biogeographic patterns in Caribbean weevils are reminiscent of those found in Caribbean Anolis lizards, frogs and snakes. Extensive in situ diversification, limited inter-island

dispersal and/or island-continent reverse colonization.

Alföldi et al. (2011) Nature

Mainland Caribbean

Caribbean

93-species Anolis phylogeny

Objective 2 – Caribbean biogeography

Biogeographic patterns in Caribbean weevils are reminiscent of those found in Caribbean Anolis lizards, frogs and snakes.

Heinicke, Duellman & Hedges (2007) PNAS- eleutherodactyline frogs

Hedges, Couloux & Vidal (2009) Zotaxa- alsophiine snakes

Credit: M. Lammertinkhttp://science.psu.edu/

Credit: S. B. HedgeS

Acknowledgements & Questions

NSF DEB-1155984 USDA (Agreement No. 58-

1275-1-335 Anyi Mazo Vargas, Dr. Robert

Anderson (sequences/specimens)

Dr. Steve Davis (AMNH), Dr. Conrad Labandeira (USNM) (fossils)

Albert Deler Hernandez, Franklyn Cala Riquelme (field assistance in Cuba)