An interesting question, asked and answered in Veterinary Practice Sept 2010. Current evidence shows that domestic cats derive fom Eurasian cats, possibly with migrations to and from America via the Bering land bridge. African cats share an ancestor with the domestic cat, but are not themselves ancestors.
Johnson, W.E et al (2006) the late Miocene radiation of modern Felidae: a genetic assessment. Science 311: 73-77
Driscoll, C.A et al (2007) The Near Eastern origin of cat domestication. Science 3017: 519-523.
these are both available via the RCVS library