Molecular ecology and systematics of sotalia dolphins

Molecular markers have the potential to disclose genetic variation and provide clues on macro and microevolutionary issues. The taxonomic and phylogenetic status of species lie within the realm of macroevolution while intraspecific matters, such as geographic population structure, social organization and mating system, pertain to microevolution. This chapter describes the findings on the molecular systematics and ecology of Sotalia dolphins, and is divided in two sections, each focusing on one of those topics. The first section shows how molecular markers have helped to settle the issue of species composition within the genus Sotalia - a matter of debate for over 140 years. To explain the controversy, a brief history of taxonomic changes in the genus since the first species descriptions is included. In addition, the section also makes phylogenetic considerations and discusses the timing of the speciation between the two accepted Sotalia species. The second section deals with the molecular ecology of Sotalia, presenting results and prospects of studies on population structure, phylogeography and social structure. Although many studies are still underway, some important findings have already been produced. The section also includes comments on new analytical developments that promise to widen our knowledge on those issues. The two sections close with a discussion of the relevance of results for the conservation and management of Sotalia species. At least two important results stem from molecular systematics and ecology studies of Sotalia dolphins, both with immediate application to their conservation. At the end of the chapter there is a presentation of the prospects for new discoveries in these fields in the near future. © 2010 by Nova Science Publishers, Inc. All rights reserved