Modern felid species descend from relatively recent (<11 million years ago) divergence and speciation events that produced successful predatory carnivores worldwide but that have confounded taxonomic classifications. A highly resolved molecular phylogeny with divergence dates for all living cat species, derived from autosomal, X-linked, Y-linked, and mitochondrial gene segments (22,789 base pairs) and 16 fossil calibrations define eight principal lineages produced through at least 10 intercontinental migrations facilitated by sea-level fluctuations. A ghost lineage analysis indicates that available felid fossils underestimate (i.e., unrepresented basal branch length) first occurrence by an average of 76%, revealing a low representation of felid lineages in paleontological remains. The phylogenetic performance of distinct gene classes showed that Y-chromosome segments are appreciably more informative than mitochondrial DNA, X-linked, or autosomal genes in resolving the rapid Felidae species radiation.It turns out the standard-issue modern housecat (Felis silvestris catus) is most closely related, genetically speaking, to African and European wildcats, and was domesticated roughly 6,000 years ago. And the main difference between cat species, wild and domesticated, is... size.
Science 6 January 2006: Vol. 311. no. 5757, pp. 73 - 77
"The cat is a wild animal that inhabits the homes of humans." - Konrad Lorenz