A paper just out in Genomics presents a very thorough study of cat genetics. Cat as is in kitty cat. The findings are expected, yet surprising in a few areas. The conclusion the authors draw about cat origins is very weak, in my view, but the information this study provides about cat breed genetics is excellent and will be of value to cats around the world.Wild cats (Felis silvestris) are or were found in a roughly continuous distribution across much of Africa (not restricted only to savannas, as is often stated), the Middle East, and Europe, and possibly disjunct in Southeast Asia (though I suspect that wild populations were continuous across southern Asia). The most “wild” (not admixed with domestic kitties) and well studied population is in the Kalahari (see photo above), where it is actually fairly easy to see them in the wild. They are quite common there. In fact, you can’t swing a dead cat without hitting one….Domestic cats have generally been thought of as having been bred from the African variety, unless you are an archaeologist, then one uses the term “Middle East” instead of “Africa,” owing to the usual Eurocentric/Holyland Centric biases.The present study investigated a large sample of domestic breeds of cats, and used previously collected data from some wild cats. It should be noted that there are not too many breeds of cats, compared, say, to dogs. There are perhaps around 700 breeds of dogs, but fewer than 100 breeds of cats.The graphic and very cute phylogeny derived from this study is reproduced here:Fig. 2. Neighbor-joining tree of cat breeds and populations. The phylogenetic tree was constructed using Cavalli-Sforza’s chord distance. Bootstrap values above 50% are presented on relationship nodes. Asian (green), Western European (red), East African (purple), Mediterranean basin (blue), and wildcat (black) populations form strongly supported monophyletic branches. European and African wildcats are closely related, whereas short branches of most all other populations indicate close relationships of these breeds and populations. Random-bred populations are indicated in italics, breeds are in standard font. Cat photographs courtesy of Royal Canin and Richard Katris of Chanan Photography.While the authors conclude that their study verifies the previously estimated “Middle Eastern” origin of cats, this is not entirely clear from their data. I would rather put it another way: Breeds found across Europe and Asia appear to be clustered geographically (with a few odd exceptions) and root nicely in a cluster that includes their sample of wild cats, indicating that cat domestication happened more or less once, in a restricted zone, and all breeds were transported (along with humans, presumably) from that core area.The Africa wild cat data they used were from southern Africa (I suspect the Kalahari, because that is where you can easily find samples). This is very far from the origin of cats, and this shows, in the great genetic distance between that sample and all the other samples. The non-African samples must be considered likely admixed with domestic cats. So, in distinguishing between an origin, say, in the Levant vs. Northeast Africa, the present study must remain mute.American cats cluster fully with the European cats. This means that if you own a Maine Coon Cat, sorry, you have neither a primordial cat or a cross breed between a cat and a raccoon!An important finding of this study is that many cat breeds are genetically a little thin on variation, and thus at risk for genetic diseases. There are, indeed, numerous such diseases found among cat breeds.The study falls to explain LOL cats, or the cat obsession with World Domination.
Thanks very much to John Lynch, who also blogged this story, for turning me on to this research.LIPINSKI, M., FROENICKE, L., BAYSAC, K., BILLINGS, N., LEUTENEGGER, C., LEVY, A., LONGERI, M., NIINI, T., OZPINAR, H., SLATER, M. (2008). The ascent of cat breeds: Genetic evaluations of breeds and worldwide random-bred populations. Genomics, 91(1), 12-21. DOI: 10.1016/j.ygeno.2007.10.009