"All knowledge degenerates into probability." 
- David Hume


My research primarily focuses on polyphenisms, which are an extreme form of phenotypic plasticity where multiple, environmentally-cued phenotypes stem from a single genotype. In particular, I am studying salamander facultative paedomorphosis, which is a retention of juvenile characteristics into adulthood (Fig. 1). I am investigating the roles of both biotic and abiotic cues involved in eliciting alternative phenotypes along with their underlying endocrinological mechanisms.
Newt Life Cycle

Figure 1. The complex life cycle of Notophthalmus viridescens. Eggs (1) are laid singly in aquatic vegetation and hatch into an aquatic larva (2). Larvae can either become paedomorphic or metamorphose. Paedomorphs are either complete neotenes (3), which have no degree of metamorphosis, or branchiates (4), which partially metamorphose. Both paedomorphic phenotypes retain gills, compressed tail fins and aquatic lifestyles. Metamorphosed phenotypes include aquatic juveniles (5), which are miniature adults, terrestrial efts (6) and semi-aquatic adults (7). Neotenes (3), branchiates (4) and semi-aquatic adults (7) are sexually mature while efts (6) and aquatic juveniles (5) are immature, but efts can take up to seven years longer than aquatic juveniles to reach sexual maturity. Illustration by Tatiana Tushyna.

Figure 2. Typical Ambystoma talpoideum adult with terrestrial morphology. Most Ambystoma spp. have an aquatic larval phase and then metamorphose into terrestrial adults.
Figure 3. Paedomorphic adult Ambystoma talpoideum salamander with retention of gilled larval morphology. Paedomorphs are fully aquatic adults.
 

Oviposition & Habitat Selection

Many of my side projects involve oviposition and habitat selection of tree frogs, mosquitoes and aquatic beetles. Using mesocosms, we construct artificial pond arrays to understand how patch characteristics influence community assembly and metapopulation and metacommunity dynamics. I am currently leading projects investigating the generality (or specificity) of fish avoidance, mass effects (i.e. density-dependence, spillover), patch quality trade-offs and temporal patterns along with their underlying mechanisms.