My work with Golden-cheeked Warblers and Black-capped Vireos
N R Giridhar Athrey,
Doctoral Fellow,
Department of Biology,
University of Louisiana at Lafayette,
Post Box 42451, Lafayette, LA 70504.
Phone: 337-849-3244; Fax; 337-482-5660;
email: giridhar[at] louisiana [dot] edu or
giri [at] giriathrey [dot] com
I am very interested in understanding how small populations change over time. Evolutionary changes in the genetics of populations need to be characterised before conclusions can be made about the status of contemporary populations. One approach towards this end is to use temporal changes in allele frequencies to estimate changes in populations over time. Small populations are suited for such studies because the signature of drift is not 'swamped' by selection or migration. Species effected by habitat loss and fragmentation over the past few decades are analogous to classical 'island' populations and provide a unique insight into evolutionary processes. I am using historical samples and contemporary samples to compare changes in a species spatial and temporal genetic attributes.
Another less well known aspect about many populations concerns dispersal - especially with regard to changes in habitats. Social factors such as philopatry, non-random selection of breeding habitat, etc, can all determine why and how far individuals disperse. Trying to tease out the relationships between social factors, habitat characteristics and dispersal is a crucial aspect of understanding how populations interact in space.
I am studying two endangered species as models to address these questions :the Golden-cheeked warbler and the Black-capped vireo both have suffered major habitat loss in the past century. Together, theses species provide a unique opportunity to examine evolutionary change in populations and allow us to answer important questions about population history. By using a combination of molecular genetics, mathematical modeling, simulations and statistical techniques I am trying to understand evolutionary processes with respect to how they relate to the conservation crises facing most species today.
