Experimental Evolution Study Station at PENN
The Department of Biology maintains an experimental garden at South Campus, approximately one mile from our labs in Leidy. In the experimental garden, we constructed an experimental orchard by planting varieties of peaches and apples (N = 40) and enclosing these trees (on dwarfing root stock) with outdoor insect rearing cages. The orchard has power, frost-free irrigation, a support shed and facility, and a comprehensive weather station. In each of our insect cages, we installed 1) data loggers to collect temperature (soil and air), humidity, and light intensity; 2) webcams to monitor Drosophila activity and behavior; 3) shelving and associated paraphernalia for Drosophila culture in situ.
Essentially, each cage (2m x 2m x 2m) functions as a Drosophila culture vial, with two major exceptions: first, these cages allow us to rear flies in truly large numbers (up to 1×106 per cage); second, these populations are exposed to natural environmental conditions, both abiotic and biotic (including daily and seasonal fluctuations in temperature, photoperiod, predators, etc.). We can effectively and experimentally manipulate fundamental aspects of Drosophila ecology and evolution in a natural setting.
Current projects using the experimental orchard include:
1. Ongoing culture of experimental populations to examine the genomic and phenotypic basis of seasonal adaptation.
2. Experimental manipulation of ecological parameters (e.g., temperature, density, inter-specific competition) in the field to examine the genomic and phenotypic response in natural, outbred, and sequenced populations of a genetic model organism.
3. Manipulation of evolution to seasonality, by means of experimentally allowing and preventing evolution to field conditions, to examine fundamental aspects of eco-evolutionary dynamics.
4. Field behavioral experiments to investigate the effects of specific phenotypes (e.g., abdominal and thoracic pigmentation) and genotypes (e.g., identified molecular polymorphism segregating at various transient receptor potential (trp) genes) on thermal preference and behavior.
5. Elucidating the genetic architecture of complex and life history traits using experimental populations cultured in a natural environmental setting.