My research explores how ecology drives organismal evolution by integraging functional morphology, comparative methods, theoretical modeling, lab experiments, and field data.
 

Evolutionary behavioral ecology 

My current project at the Merrill lab adds some evolutionary flavor to my existing research on behavioral ecology and performance. The focal systems are two species of Heliconius butterflies (H. cydno and H. melpomene). Wing patterns in Heliconius butterflies often involve Müllerian mimicry, in which multiple unpalatable species evolve similar warning color patterns (i.e. they belong to the same "mimic ring"). Moreover, the wing patterns in these butterflies also serve as cues for mate recognition and thus play a crucial role in facilitating speciation. H. cydno and H. melpomene, though closely related, possess distinct warning patterns, which limits the occurrence of hybridization when the two species come into contact. Previous work from the lab suggested that the preference for wing patterns has a strong genetic basis and that the genes for the preference and those for the wing patterns are likely linked. By combining behavioral essays and cutting-edge techniques such as QTL mapping and genome editing, we seek to uncover the genetics of mate preference in order to more broadly examine the evolution of mate preference in the context of speciation. I am also hoping to use Heliconius butterflies as a system to examine the feedback dynamics between experience and behavior.

 

Adaptive trait variation

One of my main research interests is understanding adaptive trait variation from an ecological, cost-benefit perspective. Traits that enhance fitness while simultaneously impose high costs are especially pertinent to this inquiry, as they are often under strong selection. I use autotomy (the voluntary shedding of body parts), one of the most extreme antipredator behavior within animals, as the study system to unravel how ecology drives the variation in autotomy through both natural and sexual selection. Autotomy, or the voluntary shedding of body parts, is an effective yet expensive antipredator strategy used in a diverse array of animals. From a proximal perspective, the occurrence of autotomy involves both relfex and central control, while the propensity with which organisms autotomize their body parts is ultimately regulated by the ecological environment. The complexity of autotomy therefore presents an excellent opportunity to study the evolution of extreme biological adaptations with a multi-disciplinary approach. 

Relevant publications:

Kuo C-Y and Irschick DJ. 2015. Ecology drives natural variation in an extreme antipredator trait: a cost-benefit analysis integrating modeling and field data. Functional Ecology 30: 953-963. pdf

Kuo C-Y, Irschick DJ, Lailvaux SP. 2014. Trait compensation between boldness and the propensity for tail autotomy under different food availabilities in similarly-aged brown anole lizards. Functional Ecology 29: 385-392. pdf

Gillis GB, Kuo C-Y, Irschick DJ. 2013. The impact of tail loss on stability during jumping in green anoles (Anolis carolinensis). Physiological and Biochemical Zoology 86: 680-689. pdf
 

Evo- & eco-morphology

The ecomorphoIogical paradigm, in its original form and its later expansions, has a deep influence on how I think about biological adaptations. I am interested in how the dynamics between morphology, performance and fitness might differ as a result of ecological contexts. I am also interested in situations where conflicts might arise within the morphology-performance-fitness pathway due to life-history events. A good example where ecology and performance may clash is the often substantial weight gain from a regular meal or from carrying developing offspring, as such weight gain can severely compromise the locomotor capacity of an individual. To alleviate such conflict, animal have evolved numerous behavioral and physiological mechanisms, some of which act to reduce the degree of performance impairment following weight gain, while others minimize the fitness impact under suboptimal performance. From a different perspective, I am also interested in the biomechanical underpinnings of whole-organism performance. Projects along this line included biomechanical analyses explaining how trap-jaw ants can close their mandibles with accelerations exceeding that of a bullet fired from a gun and evolutionary biomechanics of adhesion in animals. 

Relevant publications:

Kuo C-Y, Muñoz MM, Irschick DJ. In revision. Lizard foraging: a perspective integrating sensory ecology and life histories. In Lizard Behavior: Evolutionary and Mechanistic Perspectives (Eds: Vinvent Bels and Anthony Russell). CRC Press.

Guo, AH, Kuo C-Y, Sutton GP, Patek SN. In prep. A biomechanical model of the fast mandible strikes in Odontomachus trap-jaw ants.

Labonte D, Clemente CJ, Dittrich A, Kuo C-Y, Crosby AJ, Irschick DJ, Federle W. 2016. Extreme allometry of animal adhesive pads and the size limits of adhesion-based climbing. PNAS 113: 1297-1302. pdf

Kuo C-Y, Gillis GB, Irschick DJ. 2011. Loading effects on jump performance in green anole lizards Anolis carolinensis. J Exp Biol 214: 2073-2079. pdf


Collaborators

Owen McMillan, Smithsonian Tropical Research Institute
Sheila Patek, Duke University
Al Crosby, University of Massachusetts Amherst
Gary Gillis, Mount Holyoke College
Duncan Irschick, University of Massachusetts Amherst
Simon Lailvaux, University of New Orleans
Daniel Moen, Oklahoma State University
Anthony Russell, University of Calgary