Speciation in Damselflies

Speciation and Patterns of Species Diversity

One of the striking features of the damselflies in this system is the disparity in species richness between the two lake types. In the Enallagma, 34 species are associated with fish lakes and only four are associated with dragonfly lakes. In collaboration with Jonathan M. Brown, Grinnell College, and Michael L. May, Rutgers University, we have reconstructed the phylogeny of the Enallagma damselflies using DNA sequence data and morphological characters to examine various potential mechanisms for generating this disparity in species richness. Our results suggest that the simplest explanation for this disparity is that Enallagma have only recently invaded the dragonfly lake habitat. Moreover, our data indicate that about half of all the extant species have arisen sometime within the last 250,000 years from two radiating lineages, and most species arose within the last ~15,000 years. All the dragonfly-lake species are members of this young species group. These results suggest that current diversity patterns may be driven as much by macroevolutionary processes shaping speciation and extinction rates as by ecological mechanisms of coexistence.

We are now continuing this work to examine the phylogeography of these two radiations, and the ecological consequences of creating so many species so quickly.

Selected papers

McPeek, M. A., and T. E. Miller. 1996. Evolutionary biology and community ecology. Ecology 77:1319-1320.

McPeek, M. A. 1996. Linking local species interactions to rates of speciation in communities. Ecology 77:1355-1366.

McPeek, M. A., and G. A. Wellborn. 1998. Genetic variation and reproductive isolation among phenotypically divergent amphipod populations. Limnology and Oceanography 43:1162-1169.

McPeek, M. A., and J. M. Brown. 2000. Building a regional species pool: Diversification of the Enallagma damselflies in eastern North American waters.  Ecology 81:904-920.

Brown, J. M., M. A. McPeek and M. L. May. A phylogenetic perspective on habitat shifts and diversity in the North American Enallagma damselflies. Systematic Biology 49:697-712.

Turgeon, J., and M. A. McPeek. 2002. Phylogeographic analysis of a recent radiation of Enallagma damselflies (Odonata: Coenagrionidae).  Molecular Ecology 11:1989-2002.

Turgeon, J., R. Stoks, R. A. Thum, J. M. Brown and M. A. McPeek. 2005. Simultaneous Quaternary radiations of three damselfly clades across the Holarctic. American Naturalist 165:E78-E107.

Stoks, R., J. L. Nystrom, M. L. May, and M. A. McPeek,. 2005. Parallel evolution in ecological and reproductive traits to produce cryptic damselfly species across the Holarctic. Evolution 59:1976-1988.

Stoks, R., and M. A. McPeek. 2006. A tale of two diversifications: reciprocal habitat shifts to fill ecological space along the pond permanence gradient. American Naturalist 168:S50-S72.