I am interested in broad ecological principles that can explain variation among species and habitats.  Two of my main interests involve explaining variation among species in the relationship between size atmetamorphosis and fitness in amphibians and explaining variation in pond communities.  I am interested in testing my ideas in ways that contribute to the conservation of the species I study.

Variation in Pond Communities   Ponds are one of the least researched aquatic ecosystems.  I am interested in building a framework to explain variation in ponds.  To do this, I am using cattle tanks placed in forest and clearcuts to examine the effects of canopy cover on various biotic and abiotic factors.  I also plan to sample natural ponds to determine if the variation I find in the cattle tanks is similar to that of natural ponds.

Indirect Effects of Clearcuts on Tadpole Growth and Development  I plan to introduce tadpoles into the cattle tanks mentioned above.  I will use modeling to investigate which biotic and abiotic factors are most important for tadpole growth and development.

Importance of the Aquatic and Terrestrial Environment on Fitness  Many researchers have focused on the importance of the aquatic environment for the fitness of amphibians, but scientists are starting to realize that the terrestrial environment may be just as important.  In order to test these ideas, I will introduce the metamorphs from the above study into terrestrial enclosures to examine the relative contribution of the aquatic and terrestrial environment.

The Relationship between Size at Metamorphosis and Fitness  The experiments above will be done using three different species of anurans that vary in the proportion of adult size attained at metamorphosis, which I have shown by reviewing the literature predicts variation in the relationship between size at metamorphosis and fitness.  I will further test this idea by using the same methods and measures of fitness on three different species.

Master’s Research-Murray State University

While at Murray State University, working with Howard Whiteman, I worked on the effects of nutrient pollution on developmental stability in tadpoles.  I focused on nitrate and phosphate and examined nutrients in static concentrations as well as pulses.  I found no effect of phosphate on tadpoles but found that pulses of nitrate induce directional asymmetry.

Earl, J.E. and H.H. Whiteman. In Preparation. Fitness compensation hypothesis for developmental milestones.

Earl, J.E., M. Denoel, H.H. Whiteman, and C. Mecklin. In Preparation.  Variation in morph-specific sexual dimorphism in two species of polymorphic salamanders.

Earl, J.E. and H.H. Whiteman. 2009. Effects of pulsed nitrate exposure on amphibian development. Environmental Toxicology & Chemistry 28:1331-1337.

Earl, J.E. and H.H. Whiteman. In Preparation. Evaluation of phosphate toxicity in Cope’s Gray Treefrog (Hyla chrysoscelis) tadpoles.

Earl, J.E. and H.H. Whiteman. In Review. Measurement error in image analysis of fluctuating asymmetry. Copeia.

Casey, L.I., J.E. Earl, and S.A. Johnson. 2005. Attempted predation of a Pileated Woodpecker nest by a Gray Ratsnake. Florida Field Naturalist 33: 55-56.