How does lifespan evolve?
The aging group (myself, Karen Parker, and Stephanie Jemielity) working with Laurent Keller are interested in exploiting the great differences among the life-spans of social insects to study senescence. Traditional model systems do not accurately reflect the diversity of life histories due to the laboratory requirement of short generation times. Thus, the inability of these systems to fully explain life history trade-offs at the molecular level (fecundity versus longevity, reproduction versus somatic repair and maintenance) may be due to lack of relevant variation in laboratory and extant model species populations. We are overcoming this limitation by using a non-model system with great, naturally occurring variation in life span. Queens, males, and workers of the ant Lasius niger vary in orders of magnitude in their life-spans with queens living up to 28 years, workers 1-2 years, and males only months. This provides an ideal, and sometimes challenging system, to explore how natural selection has effected lifespan at the proximate level over evolutionary time.
The current focus is testing the free radical theory of aging. We have taken two approaches; 1) testing candidate genes like the superoxide dismutases and 2) using genomic techniques for a broader screen. We are cloning candidate genes, characterizing them by Northern blots, Real-Time PCR and in situ hybridization (histology done by Helene Niculita). We are also using a combination of differential display and an in house microarray chip to screen for novel genes and pathways that may be important. I also have a great interested in population genetics, molecular phylogenetics and the evolution of complex systems.