Feliformia
In contrast to the clear resolution of the basal radiations within the caniform lineage, the relative positions among the major groups of Feliformia, which individually are strongly supported as monophyletic (Felidae, Viverridae [s.s.], and clade of Hyaenidae and Herpestidae + Malagasy carnivorans), remain ambiguously resolved by the molecular data (see
Flynn et al., 1988, for comparable ambiguity suggested by morphological data). Both MP and Bayesian analyses of all-carnivoran taxa place the Viverridae as the sister group to the (Hyaenidae + (Herpestidae + Malagasy carnivoran)) clade, and thus reconstruct the Felidae, then
Nandinia, as the sequential outgroups to this clade (see:
Flynn and Nedbal, 1998;
Yoder et al., 2003;
Gaubert and Veron, 2003). However, the support for this topology is weak (BP = 64%, DI = 2,
P = 0.61;
Fig. 1).
When the analysis is repeated using the feliform-only taxa subset, the relative positions of Felidae and Viverridae (s.s) are reversed, with Felidae most closely allied with the (Hyaenidae + (Herpestidae + Malagasy carnivoran)) clade, although these results are also unpersuasive (BP = 52%, DI = 1,
P = 0.81;
Fig. 2).
Flynn and Nedbal (1998),
Yoder et al. (2003),
Yoder and Flynn (2003), and
Gaubert and Veron (2003) all recovered Viverridae as the sister-group to the combined (Hyaenidae + (Herpestidae + Malagasy carnivoran)) clade. In Flynn and Nedbal (1998; Tr-i-I only) and Gaubert and Veron (2003; Tr-i-I and CYTB only) that topology is weakly supported (parsimony BP = 61%, DI = 1; ML BP = 78%, insignificant branch length in Flynn and Nebal [1998]; < 70%, not measured, < 70%, and significant branch length for the same measures in Gaubert and Veron [2003], respectively). This topology in
Yoder et al. (2003) had weak parsimony support (BP = 61%), but strong posterior support in their Bayesian analysis (
P = .99). How
ever, all of these prior studies incorporated only Panthera leo and Felis silvestris as exemplar felids, and employed many fewer genes than in the current analysis. The addition of more taxa within the Felidae (and throughout the feliforms, and caniform outgroups, in general) and the augmentation of the gene sequence data in this analysis serve to highlight the ambiguity of the evolutionary relationships at this node. The inability of these more extensive analyses to conclusively resolve these basal relationships suggests the possibility that there may have been an early and rapid radiation within this group between the three primary feliform lineages: (1) Felidae (possibly also including
Prionodon [
Gaubert and Veron, 2003]), (2) the restricted Viverridae, and (3) the lineage (Hyaenidae + (Herpestidae + Malagasy carnivoran)).
Interrelationships within the Felidae are little resolved. In both MP and Bayesian analyses,
Felis catus (the domestic cat) and
F. silvestris (the wild cat) are grouped as sister taxa, although the strength of support for this node is somewhat weak under parsimony in the all-carnivoran analysis (
Fig. 1). When only the feliform taxa are analyzed, the strength of support for this node improves under parsimony (
Fig. 2). Beyond this, strong support for the internal relationships within Felidae does not exist. Weak support for a clade uniting
Panthera leo,
P. tigris, and
P. uncia appears in the Bayesian analyses, along with weak support for allying
Felis pardalis (ocelot) with these taxa.
Unfortunately, these analyses are unable to robustly resolve relationships within this group.
It is possible that this is due in some part to ambiguity introduced by missing data, and perhaps by the proportionally lower taxon sampling of felids (relative to herpestids and Malagasy carnivorans). All of the felid taxa in this study are represented by at least half of the potential sequences (Appendix 1), with three notable exceptions: the puma (
Felis concolor), the snow leopard (
Panthera uncia), and the cheetah (
Acinonyx jubatus), each of which is known only for a single gene. This is important, as the position of
Acinonyx appears to be incompatible between our MP and Bayesian results (although with only weak support for the conflicting placements in each; Figs.
1 and
2). Similarly, in the Bayesian analyses
P. uncia is placed as the closest relative of the lion, to the exclusion of the tiger, which is surprising given traditional taxonomic and phylogenetic interpretations (Figs.
1 and
2). Analyses of the data sets restricted to those taxa with three or more sequences better resolve some of the internal relationships of the Felidae. However, the ambiguous relationships among these taxa, especially that of the snow leopard, should be better resolved in the future with increased sequence data and more comprehensive sampling of felid taxa.
