The Landscape Genetic Patterns of Culaea inconstans

Abstract

Landscape genetics is a new field that investigates the consequences of landscape features on population genetic patterns. The small lakes of Alberta, and the brook stickleback (Culaea inconstans) that inhabit them, provide a unique system where populations are highly fragmented and isolated from one another. These lakes are prone to winterkills hypothesized to precipitate frequent bottleneck events in brook stickleback populations. As predicted, brook stickleback populations exhibited a high degree of population structure, and were hierarchically structured by small scale watersheds. AIC analyses of the role of spatial features found support for basin characteristics in driving patterns of genetic diversity, which was also consistent with the detection of recent bottlenecks in at least five of the sampled lakes. These results suggest that brook stickleback population genetic patterns are primarily controlled by processes that accelerate genetic drift, reinforcing the importance of connectivity in the maintenance of genetic diversity in fragmented landscapes.