Guanyang Zhang, Usmaan Barashat & Nico Franz Arizona State Universitytaxonbytes.org somanyinsects.org @GYZhang2

Entomological Society of America Annual Meeting, Portland, Oregon, Nov 19, 2014

© Carlos De Soto Molinari

Curculionidae: Entiminae: Eustylini

(A) E. agrestis (Boheman); (B) E. consobrinus (Marshall); (C) E. hieroglyphicus Chevrolat(D) E. impressus

(Fabricius); (E) E. nicaraguensis Bovie; (F) E. quadrivittatus (Olivier)(G) E. quinquedecimpunctatus (Olivier);

(H) E. roseipes (Chevrolat); (I) E. sulcicrus Champion(J) E. triangulifer Champion; (K) E. verecundus

(Chevrolat); (L) E. vittatus (Linnaeus)

Exophthalmus Schoenherr, 1823

85 described species; Caribbean [~45] and Neotropical mainland [~40]

Chauliopleurus Champion, 1911 [4 spp.]

Compsoricus Franz, 2012 [3]

Decasticha Champion, 1911 [5]

Diaprepes Schoenherr, 1823 [19]

Pachnaeus Schoenherr, 1826 [7]

Rhinospathe Chevrolat, 1878 [2]

Tropirhinus Schoenherr, 1823 [4]

Tetrabothynus Labram & Imhoff, 1852 [2]

Based on Franz (2012) Biol. J. Linn. Soc. (A

narrower definition is used here)

Species counts from O’brien & Wibmer (1982)

ca. 131 species

High endemism in Caribbean islands (e.g., 89% in Cuba) (Peck, 2005)

In Exophthalmus continental diversity is mainly concentrated in Central America (including Southern Mexico) (~35 spp.); low diversity in South America (8 spp.)

http://www.freeworldmaps.net/centralamerica/map.html

Species of Exophthalmus

genus complex are distributed

from Southern Mexico,

Caribbean to Northern South

America.

Can vicariance model sensu Rosen (1975) explain continent-island relationship?

Figure by Nearns & Branham, adapted from Rosen (1975),

http://kellymillerlab.com/pdf/Nearns&Branham_2008.pdf

~65 Ma ~40 Ma ~40 Ma to present

Caribbean fauna date back to

~65 Ma (late Cretaceous/early

Cenozoic)

Area relationship

Are Caribbean islands strictly a ‘colonization sink’, or could they also be a source for continental diversity?

Bellemain, E., & Ricklefs, R. E. (2008). Are islands the end of the

colonization road? Trends in Ecology & Evolution, 23(8), 461–468.

doi:10.1016/j.tree.2008.05.001

Are Caribbean islands strictly a ‘colonization sink’, or could they also be a source for continental diversity?

Unidirectional colonization from continent to islands has been the dominant model

Reverse colonization from Caribbean to Neotropical mainland documented in Anolis, birds (bananaquits, Myiarchus, parrots), turtles, and frogs (Eleutherodactylus)

Are Caribbean islands strictly a ‘colonization sink’, or could they also be a source for continental diversity?

In Anolis island to continent colonization and radiation generated >150 species in mainland

Caribbean islands Neotropical

mainland

Are Caribbean islands strictly a ‘colonization sink’, or could they also be a source for continental diversity?

What patterns would weevils show?

??

Over-water dispersal model by Hedges et al. Primarily based on vertebrates

Island-island vicariance of the GAARLandia, late Oligocene land span (Iturralde-Vinent & McPhee, 1999)

35 – 32 Ma

27 – 25 Ma

Island-island vicariance of the GAARLandia, late Oligocene land span (Iturralde-Vinent & McPhee, 1999)

16 – 14 Ma

Island-island vicariance of the GAARLandia, late Oligocene land span (Iturralde-Vinent & McPhee, 1999)

Predictions of the models

Over-water dispersal

Island-islandvicariance

Times of divergences

Scattered Clustered

Ancestral ranges Narrow or widespread

Widespread

Relationshipsamong island species

Sister relationship between any islands

(Cuba, (Hispaniola, Puerto Rico))

Biogeographic reconstruction with BioGeoBears

Extends DEC model (Dispersal, Extinction, Cladogenesis) to include founder-event dispersal (DEC + j )

Founder-event dispersal leads to cladogenesis

A ABDEC + j

(founder-event)

DEC

Taxonomic sampling

~65 spp. from the Exophthalmus genus complex

(50% of described diversity)

25 outgroups

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

• Caribbean: Cuba,

Hispaniola, Puerto

Rico, Jamaica, Lesser

Antilles (Dominica, St.

Lucia, Virgin Islands)

(50 spp.)

• Central America:

Panama, Costa Rica,

Nicaragua (15 spp.)

Molecular phylogeny and dating 6 genes: COI, COII, 12s (Mitochondrial); 28s, Ef-1α, Arginine

kinase (nuclear); 4747 bp (aligned) Dated phylogeny obtained using BEAST 1.8, with three fossil

calibration points based on Dominican ambers (16 Ma; Miocene)

Biogeographic reconstruction with BioGeoBears(Matzke, 2014)

DEC DEC + j (founder-event)

LnL = -167 LnL = -117• DEC + j fit better to

data

• Ancestral ranges resolved to single areas

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

Caribbean species are paraphyletic rendered by Central American species

Central American clade comprises a single radiation

Caribbean Central American

Colonization of Central America from the Caribbean occurred once in early Miocene (~18 Ma) through founder event dispersal

Caribbean Central American

18.8-18.1 Ma

Dispersal mechanism may involve rafting on flotsams (floating vegetation), produced by hurricanes/thunderstorms

and propelled by prevailing water currents

© Pervaze SheikhA floating island of vegetation (ca. 600 square meters)

in Amazon river, carrying a cattle egret (Bubulcus ibis) (1997 in Brazil)

Southeast to northwest surface-water currents in Caribbean since Oligocene could have facilitated oceanic over-water dispersal

Water currents directions (Hedges, 2006)

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

Reconstruction of ancestral ranges

recovered episodic dispersal events via

founder speciation

Ancestral areas were

reconstructed with BioGeoBears

& mapped on dated phylogeny

Miocene

20 10 0

PlioPl

ei

Cuba

• Island species are not monophyletic

Ma

Miocene

20 10 0

PlioPl

ei

Hispaniola

Ma

• Island species are not monophyletic

Miocene

20 10 0

PlioPl

ei

Jamaica

• Island species are not monophyletic

Miocene

20 10 0

PlioPl

ei

Puerto Rico

Ma

• Island species are not monophyletic

Miocene

20 10 0

PlioPl

ei

Lesser Antilles

Ma

• Island species are not monophyletic

Miocene

20 10 0

PlioPl

ei

Central America

Ma

• Para- or polyphyly of island

species contrasts to single origin

of mainland clade

Miocene

20 10 0

PlioPl

ei

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

• Relationships within & between

island species suggest complex

biogeographic history

Ma

Miocene

20 10 0

PlioPl

ei

Ma

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

• Cuba was the ancestral

range of entire clade in late

Oligocene24.3 Ma

Miocene

20 10 0

PlioPl

ei

Ma

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

• Founder-event dispersal – one

daughter lineage colonizes a

new range and another retains

the ancestral range

A founder

dispersal

example

Founder-event

dispersal

Miocene

20 10 0

PlioPl

ei

Ma

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

• 14 founder-event dispersals

inferred

• Nearly all prior to 13 Ma (11/14)

• Several clades diversified

within- island

Founder-event

dispersal

L P H J U C

L - 1

P 1 - 1 1 1 1

H -

J 1 - 1

U 3 3 -

C -

Cuba and Puerto Rico were major sources of colonists (11 emigrations out of these islands)

No emigration out of Hispaniola

Sink

Source

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

Cuba and Puerto Rico were major sources of colonists (11 emigrations out of these islands)

No emigration out of Hispaniola

Cuba

Central America

Lesser Antilles

Puerto Rico

JamaicaHispaniola

Immigration

Emigration

Central America was colonized from the Caribbean in early Miocene through over-water dispersal

Episodic founder-event dispersals best explain current distribution in Caribbean

Model with founder-event dispersal (DEC + j) outperformed DEC

Include additional samples from Mesoamerica (Southern Mexico and Guatemala) and Northern South America

Increase outgroup sampling to test origin of Caribbean species

Explore/devise methods to model changing geography

NSF DEB-1155984 (to N. Franz) USDA (Agreement No. 58-1275-1-335; to N. Franz) Dr. Nick Matzke (BioGeoBear analyses) Anyi Mazo Vargas (preliminary DNA data) Dr. Robert Anderson (specimens; Candiana Museum of Nature) Dr. Steve Davis (AMNU), Dr. Conrad Labandeira (USNM)

(loan of fossils) Albert Deler Hernandez, Franklyn Cala Riquelme (field

assistance in Cuba) Franz Lab: Sal Anzaldo, Andrew Jansen, Andrew

Johnston, Dr. Sangmi Lee (www.Taxonbytes.org)