Independent adaptation to riverine habitats allowed survival of ancient cetacean lineages. Proceedings of the National Academy of Sciences. Vol 97 (21): 11343–11347. Nicaragua, Colombia, Caribbean, Maracaibo, Lake, French Guiana, Amazonian Estuary, Brazilian Coast, Peruvian Colombian and Brazilian Amazon.

Project Details

Date : 2000
Volunteer Name : Cassens et al.

Project Description

Abstract: The four species of ‘‘river dolphins’’ are associated with six separate great river systems on three subcontinents and have been grouped for more than a century into a single taxon based on their similar appearance. However, several morphologists recently questioned the monophyly of that group. By using phylogenetic analyses of nucleotide sequences from three mitochondrial and two nuclear genes, we demonstrate with statistical significance that extant river dolphins are not monophyletic and suggest that they are relict species whose adaptation to riverine habitats incidentally insured their survival against major environmental changes in the marine ecosystem or the emergence of Delphinidae.