Genetic contributions to the study of taxonomy, ecology, and evolution of mayflies (Ephemeroptera): review and future perspectives

Abstract

Since the late 1970s, allozymes, microsatellites, and DNA sequence variation have been widely used to study the taxonomy, ecology, and evolution of mayflies (Ephemeroptera). Early research investigated species limits in morphologically cryptic groups and attempted to link immature and adult stages using genetic markers. Population genetic studies soon followed, with a strong emphasis on measuring gene flow as a proxy for dispersal. Most recently, direct sequencing of DNA and molecular phylogenetic tools have broadened our understanding of mayfly systematics and evolution. Interestingly, these newer approaches have also begun to re-address some of the earliest questions about species circumscription and taxonomy. Here we present an overview of genetics in mayfly research to date, focusing on how genetic approaches have been applied to taxonomy, phylogenetics, and population genetics. We identify a number of outstanding questions and highlight some of the most interesting topics for future research. These include the need for evolutionarily valid species concepts when applying genetics to taxonomy, a better understanding of how parthenogenesis may affect population genetic structure, and increased use of DNA sequence data from nuclear gene regions.

Keywords:

• dispersal
• DNA taxonomy
• heterozygosity
• mtDNA
• phylogenetics
• population
• systematics

Acknowledgements

We extend our gratitude to Arnold Staniczek and the staff at the Staatliches Museum für Naturkunde in Stuttgart for hosting the International Joint Meeting on Ephemeroptera and Plecoptera 2008. Michael Hubbard maintains an outstanding bibliography of mayfly research at Ephemeroptera Galactica ( http://www.famu.org/mayfly/mfbib.php) and Helen Barber-James provided several references. We appreciate the fruitful conversations with many conference attendees, as well as comments on the manuscript by Bern Sweeney and one anonymous referee. Our research on mayfly genetics has been funded in part by the UK BBSRC (BBS/B/04358) and the Swiss National Fund (Stipendium Nr. 68592, Research Grant Nr. 3100A0-116049).