David B. Carlon
Ph.D. University of New Hampshire, 1995
Associate Professor, Department of Zoology
University of Hawai`i
2538 McCarthy Mall, Edmondson 152
Honolulu, HI 96822
phone: (808) 956-9523
fax: (808) 956-9812
carlon@hawaii.edu
http://www2.hawaii.edu/~carlon/

Population biology, adaptation, speciation
I use molecular, experimental, and comparative approaches to probe questions related to the structure, dynamics, and evolution of marine populations. I am particularly interested in the life-history of speciation: from ancestral population to the evolution of isolating mechanisms that limit gene flow between new species. We study a variety of charismatic meso- and mega-fauna in my lab, including corals, hermit crabs, urchins, parrotfish, and… seabirds. Two currently funded projects are described below. Consult my lab website for more details on me, my students, and what we do.

1. A multidisciplinary approach to species boundaries in tropical reef corals

How new species form remains a classic and challenging question in evolutionary biology. We are using ecological, morphological, and molecular approaches to understand how reproductive isolation evolves, and the permeability of species boundaries to gene flow. This latter question is controversial among coral biologists, as species-level phylogenies based on morphology do not always agree with the increasing number of molecular data sets. At the population level, we are using an "incipient" speciation event between two forms of Favia fragum (photos, right) to test a model of ecological speciation. We are also addressing the long-term permeability of species boundaries by using morphological and molecular data sets to fit models that permit gene flow between species after an initial barrier to reproduction forms. This work is currently funded by a NSF DEB grant.

2. The genetic structure of keystone species on Pacific coral reefs

The community structure of many coral reefs has been strongly impacted by the loss of grazers because of overfishing. Conservation of key functional groups of coral reef grazers requires an understanding of the number and boundaries of unique populations within keystone species' biogeographic range. We are using microsatellite markers and Bayesian models to understand the population structure of two broadly distributed reef grazers: the Collector urchin Tripneustes gratilla and the Ember parrotfish Scarus rubroviolaceus. These projects are motivated by conservation here in Hawaii, but our broad sampling across the Pacific and Indian Oceans is revealing hotspots of molecular and phenotypic differentiation that shed light on the geography of speciation. This research has been supported by Seagrant and the Hawaiian Coral Reef Initiative.

REPRESENTATIVE PUBLICATIONS

Carlon, D. B. and C. Lippé. 2007. Isolation and characterization of 17 new microsatellite markers for the Ember parrotfish (Scarus rubroviolaceus), and cross-amplification in four other parrotfish species. Molecular Ecology Notes 7:613-616.

Edmunds, P. J., Bruno, J., and D. B. Carlon. 2004. Effects of depth and microhabitat on growth and survivorship of juvenile corals in the Florida Keys. Marine Ecology Progress Series 278:115-124.

Carlon, D. B. and A. F. Budd. 2002. Incipient speciation across a depth gradient in a scleractinian coral? Evolution 56:2227-2242.

Carlon, D. B. 1999. The evolution of mating systems in tropical reef corals. Trends in Ecology and Evolution 14:491-495.

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