Historically, there has been much thought as to how an individual’s environment and ecology (e.g., its resources, competitors, predators and pathogens) influence them, both developmentally and evolutionarily, to produce adaptive traits (Baldwin 1896; Schmalhausen 1949; Waddington, 1959). However, few empirical studies and even fewer examples from natural populations provide convincing evidence for plasticity’s role in the origins and diversification of such traits. The general goal of my research is to fill this lacuna by answering questions such as,


  1. 1)How do novel or changing environments affect the expression of genetic variation in natural populations?

  2. 2)What role does inherited epigenetic variation play in adaptation to novel or changing environments?

  3. 3)How are developmental pathways altered by environmental signals to produce morphological diversity, and how has this variation become stabilized among lineages?

My doctoral research in Dr. David Pfennig’s laboratory was conducted using natural populations of spadefoot toads that have evolved novel resource-use traits and exhibit diverse feeding strategies. Currently, I am working with Dr. Nanette Nascone-Yoder to understand how endogeneous and environmental signals create macroevolutionary diversity in gut morphology among anuran larvae from different clades.

 

Ecology, Evolution and Development

Two systems for the study of ecological and evolutionary development. Top left: Plains spadefoot toad (Spea bombifrons) tadpoles are developmentally plastic and exhibit carnivorous morphologies and behaviors after consuming fairy shrimp (photo by DW Pfennig). North American Spadefoot toads breed in ephemeral ponds that form after summer rainstorms in the Southwest (bottom right, photo by C Ledón-Rettig). Top Right: Lepidobatrachus laevis tadpoles possess a large stomach that allows to consume other tadpoles, and is evolutionarily derived (photo by N Nascone-Yoder). L. laevis is being developed as a system for evolutionary developmental studies, and is amenable to techniques such as misexpression of genes, such as GFP (bottom left, photo by C L.-R.).

Cris Ledón-Rettig, PhD

Join us this January for our exciting symposium on Ecological Epigenetics!

GFP