Independent adaptation to riverine habitats allowed survival of ancient cetacean lineages

• DOI: 10.1073/pnas.97.21.11343
• Publication Date: 2002-07-26T14:40:52Z
• Authors: Insa Cassens; Saverio Vicario; Victor G. Waddell; Heather Balchowsky; Daniel Van Belle; Wang Ding; Chen Fan; R. S. Lal Mohan; Paulo C. Simões-L...; Ricardo Bastida; Axel Meyer; Michael J. Stanhope; Michel C. Milinko...
• Keywords: Monophyly; Marine species

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 single taxon based their similar appearance. However, several morphologists recently questioned the monophyly that group. By using phylogenetic analyses nucleotide sequences from mitochondrial two nuclear genes, we demonstrate statistical significance extant dolphins not monophyletic suggest they relict whose adaptation to riverine habitats incidentally insured survival against major environmental changes in marine ecosystem or emergence Delphinidae.