Kristie Lester
Email: umlester@cc.umanitoba.ca
My general interests lie in the area of evolutionary biology and I am particularly interested in the potential roles that geography, ecology, and behaviour may play in speciation and the maintenance of species diversity within aquatic systems.
Accordingly, my current research is focused on Neotropical freshwater fishes. Although familial and generic relationships are being established among various Neotropical fish taxa, fewer studies have addressed aspects of phylogeny and evolution at the species level. Within the otophysan family Gymnotidae, which comprises the weakly electric banded-knifefishes of the genus Gymnotus and the electric eel, Electrophorus electricus, recent studies have revealed that species diversity is much greater than previously thought. Currently, 32 described species of Gymnotus are recognized. The diversity of Gymnotus species, in addition to their widespread geographical distribution (ranging from Argentina to southern Mexico), diverse habitat use, and use of weak electrical signaling, make the group well-suited to species-level phylogenetic studies of biogeography and speciation in the Neotropics. The primary objective of my thesis research is to reconstruct the relationships among the species of Gymnotus using DNA sequence data from both the mitochondrial and nuclear genomes, in addition to morphological characters. The resulting “total evidence” phylogeny will provide the necessary framework for the investigation of:
1) South and Central American biogeography, specifically the colonization of Central America by South American congeners. An understanding of how Central American Gymnotus species relate to their South American counterparts will provide insight into the processes of dispersal and speciation that have acted to create the observed species diversity within the group.
2) The origin and evolution of electric signal diversity (as it relates to predation avoidance).
A thorough understanding of the relationships amongst the species of Gymnotus will allow for a better understanding of the processes that have created diversity in the group and this in turn will produce useful insights into biological diversification in the Neotropics.
Detailed information regarding the evolution of species and electric signal diversity within the genus Gymnotus, can be found at FLMNH/Gymnotus
Preliminary phylogenetic hypothesis of Gymnotus species
based on 1205bp of the Recombination Activating Gene-2
(length=237, CI=0.86, RI=0.95).
Field collection (using electric fish finder),
San Fernando de Atabapo, Amazonas, Venezuela.