Data from: Directional selection in the evolution of elongated upper canines in clouded leopards and sabre-toothed cats

Extremely developed or specialised traits such as the elongated upper
canines of extinct sabre-toothed cats are often not analogous to those of
any extant species, which limits our understanding of their evolutionary
cause. However, an extant species may have undergone directional selection
for a similar extreme phenotype. Among living felids, the clouded leopard,
Neofelis nebulosa, has exceptionally long upper canines for its body size.
We hypothesised that directional selection generated the elongated upper
canines of clouded leopards in a manner similar to the process in extinct
sabre-toothed cats. To test this, we developed an approach that compared
the effect of directional selection among lineages in a phylogeny using a
simulation of trait evolution and approximate Bayesian computation. This
approach was applied to analyse the evolution of upper canine length in
the Felidae phylogeny. Our analyses consistently showed directional
selection favouring longer upper canines in the clouded leopard lineage
and a lineage leading to the sabre-toothed cat with the longest upper
canines, Smilodon. Most of our analyses detected an effect of directional
selection for longer upper canines in the lineage leading to another
sabre-toothed cat, Homotherium, although this selection may have occurred
exclusively in the primitive species. In all the analyses, the clouded
leopard and Smilodon lineages showed comparable directional selection.
This implies that clouded leopards share a selection advantage with
sabre-toothed cats in having elongated upper canines.