2. Model-based biogeographic inference methods (e.g.,
DEC, DIVA, BayArea) assume certain range-evolution
processes.
Dispersal
Process
Before After
Ranges
Modified from Matzke (2013)
Frontiers of Biogeography
A A
B B
A, B—area
3. Model-based biogeographic inference methods (e.g.,
DEC, DIVA, BayArea) assume certain range-evolution
processes.
Dispersal
Process
Before After
Ranges
Modified from Matzke (2013)
Frontiers of Biogeography
Extinction
A A
A A
B B
B B
A, B—area
4. Model-based biogeographic inference methods (e.g.,
DEC, DIVA, BayArea) assume certain range-evolution
processes.
Process
Before After
Ranges
Modified from Matzke (2013)
Frontiers of Biogeography
Range copying/
Sympatry
A
A
A
Tree
A
A
A
A, B—area
5. Model-based biogeographic inference methods (e.g.,
DEC, DIVA, BayArea) assume certain range-evolution
processes.
Process
Before After
Ranges
Modified from Matzke (2013)
Frontiers of Biogeography
Vicariance
A
B
AB
B
B
BA
A
A
Tree
A, B—area
6. 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
Process
Before After
Ranges Tree
A
B
A
7. 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 Models
BioGeo
BEARS
8. 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 @
9. 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
10. 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
11. 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
Jump
dispersal
DIVA (w/o J)
Only jump dispersal was inferred
12. Do biogeographic models with founder-event
jump dispersal (J) provide a better fit?
Model
Parameter estimates
Likelihood-
ratio test
Ln L d e j P
DIVALIKE -163.1 0.0052 0.0010 0.000
DIVALIKE+J -115.4 0.0000 0.0000 0.063 1.5E-22
Parameter estimates
Likelihood-
ratio test
AIC
analysis
Ln L d e j P weight ratio
-163.1 0.0052 0.0010 0.000
-115.4 0.0000 0.0000 0.063 1.5E-22 2.02E+20
Strong support from
statistical tests
Adding jump dispersal led
to much higher log likelihood
13. 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
14. Neotropical mainland was colonized by Caribbean
island species in the early Miocene (~18 MYA)
Caribbean Central America
15. Current finding corroborates an emerging idea that
islands can serve as a source for continental diversity.
Bellemain & Ricklefs (2008) TREE
16. 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
MainlandCaribbean Caribbean
93-species Anolis phylogeny
17. 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. Lammertink
http://science.psu.edu/
Credit: S. B. HedgeS
18. 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)
Notes de l'éditeur
This slide 12; cumulative 12
Model-based historical biogeographic inference methods each assume a certain set of range-evolution processes, such as dispersal…
This slide 3; cumulative 15
Extinction [1000, 2000]
This slide 6; cumulative 21
Range-copying or sympatry [1000, 2000]
This slide 3; cumulative 24
And vicariance [1000, 2000]
This slide 30; cumulative 54
In a recent study published in “Systematic Biology” Nick Matzke added founder-event speciation as a new biogeographic process into models of range evolution, which is also called jump dispersal. At cladogenesis one daughter lineage colonizes a new range while the other inherits the ancestral range.
This slide 12, cumulative 66
The R package BioGeoBEARS implements previous processes as well as jump dispersal. This package also allows you to statistically test biogeographic models just like selecting DNA substitution models.
This slide 33, cumulative 99 s
My study organisms are broad-nosed weevils in the Exophthalmus genus complex. More than 80 species have been described from the Caribbean and nearly all of them are endemic to a single island. This group represents an ideal case for testing for founder-event speciation as well as studying aspects of Caribbean biogeography.
This slide 10 s, cumulative 109 s
I reconstructed a dated molecular phylogeny. The specimen samples covered major Caribbean islands as well as the mainland.
This slide 22, cumulative 131 s
The first question I asked was “What are the effects of modeling founder-event jump dispersal on ancestral range evolution estimation?” For simplicity, let’s focus on just part of the tree. On the left, with jump dispersal the most probable ancestral ranges were always estimated to be a single area. This contrasts to the widespread ancestors in the inference without jump dispersal, shown on the right.
This slide 12, cumulative 143
Besides, on the left all the biogeographic processes were jump dispersal events. Whereas without jump dispersal, I would have to infer several range-evolution processes, some of which require ad hoc explanations.
This slide 20s, cumulative 163 s
Do models with jump-dispersal provide a better fit? First, inferences with jump dispersal had log likelihood values higher by nearly 50 units. Second, two statistical tests, likelihood-ratio test and Akaike information criterion weights, both strongly favored models with jump dispersal.
This slide 9, cumulative 192 s
Based on the biogeographic inference with jump dispersal, it appears that inter-island dispersal and in situ diversification were the main driving forces of speciation in these weevils. However, jump dispersal occurred infrequently. In contrast, range-copying was inferred at most of the nodes, leading to extensive within-area in situ diversification.
For instance, at least two radiations occurred within the island of Cuba during the last 10 Million years.
This slide 10 s, cumulative 202 s
I also recovered a rather intriguing result. Central America was colonized by a Caribbean ancestor, leading to a large continental radiation.
This slide 9, cumulative 219
This result corroborates an emerging idea that islands could serve as a source for continental diversity.
This slide 22, cumulative 241
To further put my study into context, the various biogeographic patterns I recovered in these weevils, namely extensive in situ diversification, limited inter-island dispersal, and island-to-continent reverse colonization, are quite similar to those found in the Anolis lizards…
This slide 22, cumulative 241
eleutherodactyline frogs and alsophiine snakes. Hence, I provide further evidence towards generalizing theories of Caribbean biogeography.
This slide 6 s, cumulative 247 s.
With that I would like to thank NSF and USDA for funding and several colleagues. Thank you for your attention and I will entertain questions.