within the family Delphinidae. Although the LeDuc et al.
[3] phylogeny included representatives of all species
within the subfamily Delphininae, each species was
represented by only a few sequences (or in the case of
May-Collado et al. [24], single sequences and an
incomplete survey of the taxa within the subfamily);
the mitochondrial cytochrome b locus was unable to
completely resolve branching order within the Delphininae
[3,24]. The lack of resolution in the cytochrome b
phylogeny suggests the Delphininae are the product of a
recent radiation; divergence among the numerous taxa is
small, rendering resolution of branching order difficult.
The LeDuc et al. [3] cytochrome b phylogeny also
suggests polyphyly of the delphinine genera Stenella
and Tursiops and this result for Stenella is also supported
by May-Collado et al. [24]. So far, nuclear and combined
analyses concerning the Delphininae raise more questions
and provide support for only a few internal nodes
within the subfamily [20]. The polyphyletic genera and
lack of branching order resolution among many of the
delphinine taxa point to a need for a new approach to
discerning the evolutionary relationships among the
species in this subfamily and perhaps a revision of the
subfamily (Figure 1).