Hastings Natural History Reservation

30 Apr, 10 AM - 27 Jun, 05 AM

I am interested in the causes and consequences of phenotypic variation in natural populations. Understanding factors underlying phenotypic variation and the functional effects of this variation can give insight into how traits may change over time or across variable environments. Phenotypic distributions arise from the interaction of evolutionary factors (phylogenetic history, genetic drift, gene flow, selection) and environmental effects on development (Pfenning et al., 2010). Evolutionary shifts in heritable phenotypes are necessary for diversification of populations and ultimately, speciation. For this reason, the processes shaping phenotypic variation among and within subdivided populations have been a focus of research (Bonnin et al., 1996; Lynch et al., 1996; Pfenninger and Magnin, 2001). Although any evolutionary mechanism may be responsible for the divergence of heritable traits in allopatric populations, there has been considerable empirical and theoretical work devoted to how divergent selection can drive speciation (Rice and Hostert, 1993; Schluter 1996; Losos et al., 1997; Nagel and Schluter, 1998; Orr and Smith, 1998; McKinnon et al., 2004; Rundle and Nosil, 2005; Rundle et al., 2005; Schluter, 2001; Schluter, 2009). I will examine causes and consequences of phenotypic variation within and across populations of western black widow spiders (Latrodetus hesperus), in which northern and southern populations may be two biological species (Barrett & Hebert, 2005; Kasumovic & Andrade 2004). Preliminary (small sample-size) laboratory data suggest these populations may be reproductively isolated (interpopulation matings resulted in non-viable offspring). Moreover, northern and southern populations (Kasumovic and Andrade, 2004) are apparently diverging in male size and pheromone signaling. Other data suggest that within-population variation in male size is also extensive (ranging from 3.2-5.2mm in leg size, and 6.10 to 27.1mg in mass; Brandt and Andrade, 2007). These incipient species provide a unique opportunity to explore the processes that shape the divergence of phenotypic traits related to mating in geographically isolated populations, and assess how these are related to the processes generating phenotypic variation within species.

Visit #28227 @Hastings Natural History Reservation

Approved

Under Project # 25093 | Research

Cause and consequences of phenotypic variation in natural populations of western black widows (Latrodectus hesperus)

graduate_student - University of Toronto

Reservation Members(s)

Sheena Fry Apr 30 - Jun 27, 2012 (59 days)
Sheena Fry Apr 30 - Jun 27, 2012 (59 days)

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