Macroevolution | Feeding Ecology | Functional Morphology

Below are short descriptions of multiple ongoing research projects, which generally pertain to the feeding ecology, functional morphology, and macroevolution of freshwater fishes, Caribbean anole lizards, and North American salamanders.

Ecological and evolutionary implications of the oral and pharyngeal jaw systems in ray-finned fishes

 

 

I am interested in many aspects of jaws. How do they function? How have they evolved? Ray-finned fishes have two jaw systems - oral and pharyngeal jaws - that provide a versatile feeding apparatus. I am interested in how these jaw systems respond to feeding ecology and the degree of functional and evolutionary integration between the jaw systems.

Thumbnail: lower pharyngeal jaws of several Neotropical cichlids depicting the diversity of shape and dentition, dissected and photographed by E.D.B.

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Evolutionary ecology of North American minnows

 

I'm interested in the feeding ecology and macrohabitat use of diverse minnow assemblages throughout the Eastern United States, especially specialization along the benthic-pelagic environmental axis. I'm also broadly interested in ecological and functional differences between assemblages in mountain streams (e.g., the New River) and lowland plains (e.g., Uphapee Creek)

 

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Thumbnail: Minnows from the Southern Appalachians (left column) and lowland plains (right column) (counter-clockwise from top left): Notropis scabriceps, Luxilus coccogenis, Pimephales notatus, Phenacobius teretulus, Nocomis leptocephalus, Nocomis platyrhynchus, Phenacobius catostomus, Macrhybopsis storeriana, Ericymba buccata, Pimephales vigilax, Cyprinella gibbsi, Notropis baileyi. All photographs by E.D.B.

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Parallel evolution and ecological speciation in South American pike cichlids (Crenicichla)

 

Crenicichla are a unique radiation of South American cichlids that are elongate predators. My collaborators and I are using phylogenomics (UCEs and ddRADseq) to evaluate Crenicichla phylogeny and population genetics. Secondly, I am interested in the parallel evolution of similar sets of ecomorphs in the Iguazú and Uruguay Rivers. These two clades have independently and rapidly evolved several ecomorphs, including species that crush molluscs with hypertrophied pharyngeal jaws, others that pry clinging invertebrates from rock crevices with hypertrophied lips, and yet others that pick at periphyton with compact oral jaws. 

Read more about this project here.

 

Thumbnail: Parallel adaptive radiation in the Iguazu (yellow) and Uruguay (blue) River species flocks. Paintings and design by Julie Johnson.

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Macroevolutionary features of adaptive radiation

 

I am interested in theory about adaptive radiation - how and why it occurs, what it looks like, how to detect and quantify patterns and underlying processes. More specifically, how different sources of ecological opportunity - extinction of competitors, evolution of a key innovation, or colonization of a novel environment - influence morphological, ecological, and species diversity. I mostly use phylogenetic comparative methods, but also ecology and life history, to study both model and non-model groups. My research in this area principally involves cichlids, but also marine fishes and anole lizards. The co-evolution of form and function, integration between different anatomical systems (e.g., the oral and pharyngeal jaws), key innovations, and testing classic adaptive radiation hypotheses (i.e., time-dependent diversification) are a major focus.

Read more about cichlids here.

Thumbnail: Geophagus abalios, cleared and stained by E.D.B. and photographed with assistance from Alexus Roberts.

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Macroevolutionary consequences of trade-offs

 

A central part of my postdoctoral work in the Muñoz Lab deals with trade-offs, including the jaw system of fishes and limbs of lizards and salamanders. My primary interest is the macroevolutionary effects of trade-offs, especially (1) if a trade-off acts as a constraint or promotor of diversification, (2) if the effect is symmetrical (or asymmetrical) along the trade-off, and (3) if the effect varies according to the extent to which a trade-off is explored.

 

 

Collaborators: Martha Muñoz

 

 

 

Thumbnail: A red salamander (Pseudotriton ruber) along a tributary to Halawaki Creek, Alabama, USA, photographed by E.D.B.