Genets (Carnivora, Viverridae) in Africa: an evolutionary synthesis based on cytochrome b sequences and morphological characters

Abstract

The taxonomy of the genets (genus Genetta) has long been discussed, thus hampering endeavours towards evolutionary reconstruction. Sequence data from the complete cytochrome b gene (cyt b) were generated for 50 specimens representing 15 morphological species in order to allow the production of the first exhaustive molecular phylogeny of the genets. Second, a revised morphological matrix comprising 50 characters was combined with the cyt b data to estimate the level of morphological homoplasy. Phylogenetic analyses were conducted using parsimony, maximum likelihood and Bayesian procedures. Our results based on cyt b contradict a part of the traditional taxonomy of genus Genetta, the servaline and small-spotted genets being paraphyletic, but confirmed the species status recently re-investigated for three genets belonging to the large-spotted complex, including the newly described G. bourloni. The combined analysis yielded similar results although morphological characters were clearly homoplasic. Partitioned Bremer supports indicated conflicting signals between the two data sets throughout the tree, and species-diagnostic characters, useful for delimiting species boundaries, were significantly correlated to habitat. However, morphological data supported the monophyly of clades (G. victoriae, other genets) (G. servalina, G. cristata), large-spotted genet complex and forest forms. Our results suggest a complex evolutionary history of the genets in Africa, with a Poiana-like ancestor inhabiting rain forest, and then a diversification involving two independent invasions of open habitats and one reversion to rain forest. Divergence estimates based on cyt b revealed that splitting events within genets partly follow a climatic speciation model during the cyclical periods of the Quaternary, although ‘primitive’ rain forest lineages diverged earlier, during the Late Miocene and Early Pliocene.