Sunday, June 24, 2012

Cats and Human Migration

Cats slowly domesticated themselves starting about 10,000 years ago. Unlike other domesticated animals who mostly live in herds and eat plants, cats are solitary and eat meat (Driscoll, Clutton-Brock, Kichener, & O’Brien, 2009). They found that “domestic cats arose in a single locale, the Middle East” (p. 71). On Cyprus, an island in the eastern Mediterranean, archeologists discovered the body of an eight-month-old cat intentionally buried near a person. The two burials were dated as being9,500 years old (Vigne, Guilaine, Debue, & Gerard, 2004). Unlike dogs, cats more closely resemble their wild ancestors, can survive without human help, and resist human efforts to limit their breeding opportunities. Left alone, cats tend not to wander far from where they were born. Cats, Lloyd (1986) suggests, migrate slowly “less than one mile per generation” (p. 51). Despite their tendency to not move much on their own, cats are found everywhere around the world either because their owners took them with them as they moved from place toplace or because the cats stowed away on ships. Thus, the study of cat genetics, interesting for its own sake, also reveals much about the migration of humans over the last 10,000 years from the earliest civilizations in western Asia (see chapter 2) to the rest of Europe and East Asia, and eventually, to the entire world.

            The genetic key opening the rest of this story began when Searle (1947) first observed and calculated gene frequencies for wild type and mutant cat coat colors and patterns (e.g., wild or tabby, nonagouti or black, blotched tabby, sex linked orange, and others) in London. Since then hundreds of similar surveys have been conducted around the world and have been used to infer the historical patterns of human migration. In Europe, the pattern of nonagoutimutation, as measured by gene frequency analysis, may point to early human dispersals from Phoenicia and Greece to North Africa (Todd, 1997). Later migrations can also be interpreted through cat genetics. New York’s cats, even now, are more genetically similar to the cats of Amsterdam than to the cats of Boston, reflecting the movement of people and their cats from Holland to North America starting in 1626 (Lloyd, 1986).

Driscoll, C. A., Clutton-Brock, J., Kichener, A. C., & O’Brien, S. J. (2009). The taming of the cat, Scientific American, 300(6), 68-75.

Lloyd, A. T. (1986). Pussy cat, pussy cat, where have you been?, Natural History, 95(7), 46-52.

Searle, A. G. (1947). Gene frequencies in London’s cats, Journal of Genetics, 49, 214-220.

Todd, N. B. (1977). Cats and commerce, Scientific American, 237(5), 100-107.

Vigne, J. D., Guilaine, J., Debue, K., & GĂ©rard, P. (2004). Early taming of the cat in Cyprus, Science, 304, 259.