Genetic Approaches to Understanding Marine Metapopulation Dynamics
Abstract
This chapter demonstrates how genetic approaches can help define three fundamental aspects of marine metapopulation dynamics: what a population is, how populations are connected, and what impact population extinction recolonization events have. Genetic markers can contribute to the recognition and understanding of metapopulations in the sea in a number of ways. Much work has gone into measuring subdivisions among populations, detecting phylogeographic breaks and exposing cryptic species, all of which has helped to define the spatial scale of populations for different species. The population turnover characteristic of strictly defined metapopulations should be detectable by genetic means, but supporting demographic data and temporal sampling regimes greatly strengthen any conclusions that can be drawn. The genetic impact of population turnover hinges on whether colonists are small groups of related individuals or large groups drawn from a larger geographically mixed pool. Progress toward a better understanding of marine population dynamics will come from both new analyses and new types of data. All these new analytical approaches are data hungry, and increasingly the data they will analyze will come from nuclear gene sequences. The greatest progress in understanding the dynamics of marine populations will come from coupling new genetic approaches with other sources of data. Even sophisticated genetic analyses can have a difficult time detecting certain population dynamics without additional information and some new analyses depend on intensive temporal sampling. © 2006 Elsevier Inc. All rights reserved.