Presentation Detail

Phenotypic Plasticity

O'Brien, Katherine [1], Schmidt, Paul [1].

Clinal Patterns of Phenotypic Plasticity for Two Species of Drosophila.

The environment mediates how genetic variation is translated into the phenotypic variation on which selection can act. This environmentally sensitive production of alternative phenotypes is referred to as phenotypic plasticity. Environmental factors such as heterogeneity are thought to select for and maintain a plastic response in natural populations. To address these questions wild populations of both Drosophila melanogaster and Drosophila simulans from three regions along the east coast of the United States were surveyed to quantify the patterns and extent of the plastic response in two closely related species. D.melanogaster and D. simulans have overlapping ranges using the same rearing sites and food resources. However, these two species have very different population structures and overwintering patterns. D. melanogaster can overwinter in temperate regions allowing for resident populations, whereas D.simulans lacks the ability to overwinter and must reinvade northern regions to reestablish populations. This system allows us to assess if predictions about heterogeneity in the environment are important for natural populations of two similar species that encounter different scales of environmental heterogeneity. To quantify plasticity, eggs were collected from isofemale lines and reared in four different environmental conditions and a panel of life history traits were measured. Each line was giving a plasticity score that was derived by using a statistic to standardize the intensity of the response to different environments while accounting for the standard deviation within that line, yielding an unbiased estimation of response. These results show parallelism in direction of reaction between the species but pronounced difference between species in the intensity of response. The regions also show differences in the ability to respond plastically that appears to vary along the environmental cline. These results yield insight into the possible role of environmental heterogeneity in maintaining plastic responses in natural populations.

1 - University of Pennsylvania , Biology, 443 South University ave , Philadelphia, PA, 19104, USA

Keywords:
phenotypic plasticity
D. melanogaster 
D. simulans 
Photoperiod .

Presentation Type: Regular Oral Presentation
Session: 100
Location: Cotton A/Snowbird Center
Date: Monday, June 24th, 2013
Time: 8:30 AM
Number: 100001
Abstract ID:65
Candidate for Awards:W.D. Hamilton Award for Outstanding Student Presentation