Evolutionary Feeding Biomechanics

Hello, there and welcome. I'm a biologist interested in how form relates to function, in other words, why animals look and act the way they do. I integrate functional morphology, macroevolutionary methods, and natural history to understand how weird, new, and novel traits come to be - and how these traits aid in animal performance in their day-to-day lives. 

 

I use experimental methods, using high speed video and in vivo observations of fish behavioral ecology. I meld these observations with high-resolution bio-imaging, like CT scanning and scanning electron microscopy, to visualize animal anatomy up-close. Finally, I use phylogenetic comparative methods to examine these traits and behaviors in the context of how my focal study species are related to one another. This toolkit of complementary methods lets me discern what aspects of animal phenotype are shared in common with relatives, versus those traits that are newly repurposed for some behavior.

 

I'm currently a post doc at University of Michigan, in the Museum of Paleontology, and affiliated with UM's Museum of Zoology. Currently, my research is investigating anatomical novelties in air-breathing fishes, and how these traits have (or have not) shaped the evolutionary mode and tempo of the anabantarians: gouramis, bettas, climbing perch, snakeheads, swamp eels, spiny eels, and crocodile pipefishes. 

 

Thanks for stopping by!

How does our food shape how we look and behave?

Why study feeding?

freshwater ray gnawing on an insect
freshwater ray gnawing on an insect

Our food gives us the energy that drives our growth & self-repair. The act of getting that food, foraging, has a considerable effect on our fitness, our net reproductive output - nature's currency upon which selection acts.  How well we catch prey, consume prey, and digest it is our performance - and the higher our performance, the more metabolic energy we can bring to bear growing, maturing, and just generally being alive.  Not only for these important reasons - studying how animals feed is just intrinsically fascinating (at least to me) and who doesn't like food, no?  Given the preoccupation animals have with finding their next meal, the question of how our prey shapes our behaviors and appearance has driven my research program over the last several years.  What materials comprise your food?  How do these materials and structures change how animals approach capturing, processing, and digesting these foods?  

Why study piranhas and pacu?

Pacu skull CT scan
Pacu skull CT scan

The serrasalmids are an interesting group - not a large group, nor a small group of fishes (with just under a hundred described species), although there are dozens of undescribed taxa found throughout South America. Although most people think of piranhas as hypercarnivores - the majority of species in Serrasalmidae consume plant material like seeds, fruits, leaves, and nuts - piscivores are relatively recent on the scene. What is remarkable about these fishes is that they have relatively immobile skulls, relative to other fishes, and yet manage to process an incredible array of prey; prey composed of myriad materials with diverse qualities... How does such a simple system succeed in processing such diverse prey? How does cranial architecture and tooth shape interact to apply forces to prey and resist breakage in return? I am building a phylogenomic tree with Dr. Guillermo Orti at George Washington University to build an evolutionary scaffold with which we will examine feeding evolution across the serrasalmids. This effort will include collaborators from the Smithsonian, Royal Ontario Museum, and the GWU Departments of Biology, Biomimetics, and Engineering - to answer 'how does your food shape how you look and behave.'

Why study sharks and rays?

Freshwater ray from Guyana
Freshwater ray from Guyana

Sharks, skates, rays, & chimaeras (chondrichthyan or cartilaginous fishes) are an amazing group of animals that survived the "test of time."  From their major radiation in the Devonian, cartilaginous fishes have been incredibly successful in the evolutionary game.  Although superficially similar to prehistoric chondrichthyans, modern sharks (neoselachians) are by no means outdated or "primitive."  They are both a window to understanding how and why early fishes were so successful and also a fascinating study system in terms of their unique (in regards to other vertebrates) characteristics, such as their predominantly cartilaginous skeleton, few overall skeletal elements, large size, predatory attributes & behavior, unique morphological & physiological traits (lack of a swim bladder, urea production, serial tooth replacement, the list goes on...).  Understanding evolutionary traits in context is key to understanding how that organism has come to function in its environment, which has direct application to management and ecological interest.

Why study functional and evolutionary morphology?

Dasyatis geijskesi - Demerara Estuary 2015
Dasyatis geijskesi - Demerara Estuary 2015

 

I'm chiefly interested in the evolution of form and function - why things look the way they do.

 

Functional morphology, molecular phylogenetics, and biomechanics are all sub-disciplines within biology that can teach us how an organism has adapted or evolved to function within a particular niche or ecosystem - the who, the what, and the when of natural history.  These disciplines provide complementary quantitative means by which scientists can understand how an organism performs a particular task, be it locomotion, feeding, or other behavior - and how augmentation or variation of a particular structure, modulated by behavior - allows that organism to achieve a particular level of fitness in its habitat / niche.  In more general terms, functional morphology allows us to answer (tentatively) how well an organism performs a particular task in relation to other organisms.  This understanding is most frequently applied to evolutionary studies seeking to understand why some groups are more speciose (species rich) than others.