Dr. Johanna kowalko

Assistant Professor of biology

2013 Ph.D., Genetics Harvard University, Boston MA
2005 B.A., Biology Brown University, Providence MA

How does genetic variation, interpreted through developmental processes,
contribute to phenotypic variation? How do the phenotypes that result from this variation
contribute to relative fitness? My research program addresses these questions using the
blind cavefish, Astyanax mexicanus. A. mexicanus exists in a river-dwelling surface
form, as well as in multiple populations that have been trapped in, and have adapted to
life in subterranean caves. Cavefish have adapted to survive and thrive in the cave
environment through the modification of morphological, physiological and behavioral
traits. While surface and cavefish have strikingly divergent phenotypes, they are
interfertile, and are therefore a powerful genetic model of evolution. Furthermore, many
of these cave populations have evolved from independent colonization events, allowing
for the examination of repeated evolution. In addition, the small size, ability to live and
breed in the laboratory, and short generation time of these fish make Astyanax an
extraordinary system for genetic and developmental studies. These advantages,
combined with the definable characteristics of the cave habitat under which these fish
evolved, make Astyanax an extraordinary model system for studying the evolution of
morphological and behavioral traits and their ecological significance. My research
program leverages this model system to identify genes and genetic changes responsible
for the evolution of organisms, to study the role these changes play at a functional level
in generating complex traits and, ultimately, their effects on fitness.

Contact Info
jkowalko@fau.edu
Office: MC-19, Room 207
Office phone: (561) 799-8102