I was a postdoctoral fellow in the Krueger's lab at Michigan State University and Dr. Andrew Muir from the Great Lake Fishery Commission.
Following a similar ecological focus of my PhD, I will expand this research theme to broader geographic and taxonomic scales, studying parallel evolution of lake charr among several North American lakes. The overall proximate goal of this research is to describe the functional ecology of lake charr morphotypes and ultimately to identify and understand the key ecological variables to develop a conceptual model that provides a consistent explanation for the presence/absence of morphotypes among lake systems. Before a broad North American comparison can be accomplished, unusual lake systems must be studied that do not fit the current model of sympatric ecomorphotypic differentiation (large lakes, bathymetrically complex, 3-dimensional distribution of energy sources). I focused my first year at Michigan State to study lake charr in Rush Lake (MI) using geometric morphometrics, molecular biomarkers, stomach content analysis, analysis of genetic neutral markers, and back-calculated growth models. The occurrence of two lake charr morphs in a lake as small as Rush Lake contradicts the notion that lake charr diversity only occurs (i.e., either originate or be maintained) in large lakes. The direct relationship found within Rush Lake between morphology and ecological characters, combined with the lack of reproduction isolation, provided evidence that local environmental variation contributed to the maintenance of morphological differentiation, with forms of lake charr related to function (depth in this case). In contrast to the highly variable congeneric Arctic charr, which readily radiates into benthic and pelagic morphs in many small and large lakes throughout the holarctic, lake charr have been incorrectly been associated with low intraspecific variation. By illustrating processes(s) of intraspecific divergence other than the traditional benthic vs. pelagic model found in the literature (e.g., littoral–profundal resource axis), lake charr offer new perspectives in the investigation of mechanism(s) of phenotypic plasticity in post-glacial lakes.
Following a similar ecological focus of my PhD, I will expand this research theme to broader geographic and taxonomic scales, studying parallel evolution of lake charr among several North American lakes. The overall proximate goal of this research is to describe the functional ecology of lake charr morphotypes and ultimately to identify and understand the key ecological variables to develop a conceptual model that provides a consistent explanation for the presence/absence of morphotypes among lake systems. Before a broad North American comparison can be accomplished, unusual lake systems must be studied that do not fit the current model of sympatric ecomorphotypic differentiation (large lakes, bathymetrically complex, 3-dimensional distribution of energy sources). I focused my first year at Michigan State to study lake charr in Rush Lake (MI) using geometric morphometrics, molecular biomarkers, stomach content analysis, analysis of genetic neutral markers, and back-calculated growth models. The occurrence of two lake charr morphs in a lake as small as Rush Lake contradicts the notion that lake charr diversity only occurs (i.e., either originate or be maintained) in large lakes. The direct relationship found within Rush Lake between morphology and ecological characters, combined with the lack of reproduction isolation, provided evidence that local environmental variation contributed to the maintenance of morphological differentiation, with forms of lake charr related to function (depth in this case). In contrast to the highly variable congeneric Arctic charr, which readily radiates into benthic and pelagic morphs in many small and large lakes throughout the holarctic, lake charr have been incorrectly been associated with low intraspecific variation. By illustrating processes(s) of intraspecific divergence other than the traditional benthic vs. pelagic model found in the literature (e.g., littoral–profundal resource axis), lake charr offer new perspectives in the investigation of mechanism(s) of phenotypic plasticity in post-glacial lakes.