Cats and Humans - A 12,000 Year Old Commensal Relationship

Is Your Cat Truly Domesticated? According to Science....

Wildcat Felis silvestris
Three European Wildcat Kittens in Germany (Felis silvestris). Raimund Linke / Getty Images

The modern cat (Felis silvestris catus) is descended from one or more of four or five separate wild cats: the Sardinian wildcat (Felis silvestris lybica), the European wildcat (F. s. silvestris), the Central Asian wildcat (F.s. ornata), the sub-Saharan African wildcat (F.s. cafra), and (perhaps) the Chinese desert cat (F.s. bieti). Each of these species is a distinctive subspecies of F. silvestris, but F.s. lybica was ultimately domesticated and is an ancestor of all modern domesticated cats.

Genetic analysis suggests that all domestic cats derive from at least five founder cats from the Fertile Crescent region, from where they (or rather their descendants) were transported around the world.

Researchers analyzing cat mitochondrial DNA (Ottoni and colleagues 2016) have identified evidence that F.s. lybica was distributed across Anatolia from the early Holocene (ca. 11,600 years ago) at the latest. The cats found their way into southeastern Europe before the onset of farming in the Neolithic. They suggest that cat domestication was a complex long-term process, because people took cats with them on overland and ship-board trade facilitating admixture events between geographically separated F.s. lybica and other wild subspecies like F.S. ornata at different times.

How do you Make a Domestic Cat?

There are two difficulties inherent in determining when and how cats were domesticated: one is that domesticated cats can and do interbreed with their feral cousins; the other is that the primary indicator of cat domestication is their sociability or docility, traits not easily identified in the archaeological record.

Instead, archaeologists rely on the size of animal bones found in archaeological sites (domesticated cats are smaller than feral cats), by their presence outside of their normal range, if they are given burials or have collars or the like, and if there is evidence that they have established a commensal relationship with the humans.

Commensal Relationships

Commensal behavior is the scientific name for "hanging around with humans": the word "commensal" comes from Latin "com" meaning sharing and "mensa" meaning table. As applied to different animal species, true commensals live entirely in houses with us, occasional commensals move between houses and outdoor habitats, and obligate commensals are those that can only survive in an area because of their ability to occupy houses.

Not all commensal relationships are friendly ones: some consume crops, steal food, or harbor disease. Further, commensal does not necessarily mean "invited in": microscopic pathogens and bacteria, insects, and rats have commensal relationships with humans. Black rats in northern Europe are obligate commensals, which is one of the reasons the medieval bubonic plague was so effective at killing people.

Cat History and Archaeology

The oldest archaeological evidence for cats living with humans is from the Mediterranean island of Cyprus, where several animal species including cats were introduced by 7500 BC. The earliest known purposeful cat burial is at the Neolithic site of Shillourokambos. This burial was of a cat buried next to a human between 9500-9200 years ago.

The archaeological deposits of Shillourokambos also included the sculpted head of what looks like a combined human-cat being.

There are a few ceramic figurines found in the 6th millennium BC site of Haçilar, Turkey, in the shape of women carrying cats or catlike figures in their arms, but there is some debate about the identification of these creatures as cats. The first unquestioned evidence of cats smaller in size than the wildcat is from Tell Sheikh Hassan al Rai, an Uruk period (5500-5000 calendar years ago [cal BP]) Mesopotamian site in Lebanon.

Cats in Egypt

Up until very recently, most sources believed that domesticated cats became widespread only after the Egyptian civilization took its part in the process. Several strands of data indicate that cats were present in Egypt as early as the predynastic period, nearly 6,000 years ago.

A cat skeleton discovered in a predynastic tomb (ca. 3700 BC) at Hierakonpolis may be evidence for commensalism. The cat, apparently a young male, had a broken left humerus and right femur, both of which had healed prior to the cat's death and burial. Reanalysis of this cat has identified the species as the jungle or reed cat (Felis chaus), rather than F. silvestris, but the commensal nature of the relation is unquestioned.

Continued excavations at the same cemetery at Hierakonpolis (Van Neer and colleagues) have found a simultaneous burial of six cats, an adult male and female and four kittens belonging to two different litters. The adults are F. silvestris and fall within or near the size ranges for domesticated cats. They were buried during the Naqada IC-IIB period (ca. 5800–5600 cal BP).

The first illustration of a cat with a collar appears on an Egyptian tomb in Saqqara, dated to the 5th dynasty Old Kingdom, ca 2500-2350 BC. By the 12th dynasty (Middle Kingdom, ca 1976-1793 BC), cats are definitely domesticated, and the animals are frequently illustrated in Egyptian art paintings and as mummies. Cats are the most frequently mummified animal in Egypt. 

The feline goddesses Mafdet, Mehit, and Bastet all appear in the Egyptian pantheon by the Early Dynastic period--although Bastet is not associated with domesticated cats until later.

Cats in China

In 2014, Hu and colleagues reported evidence for early cat-human interactions during the Middle-Late Yangshao (early Neolithic, 7,000-5,000 cal BP) period at the site of Quanhucun, in Shaanxi province, China. Eight F. silvestris cat bones were recovered from three ashy pits containing animal bones, pottery sherds, bone and stone tools. Two of the cat jaw bones were radiocarbon dated between 5560-5280 cal BP. The size range of these cats falls within that of modern domesticated cats.

The archaeological site of Wuzhuangguoliang contained a nearly complete felid skeleton laid on its left side and dated to 5267-4871 cal BP; and a third site, Xiawanggang, contained cat bones as well.

All of these cats were from Shaanxi province, and all were originally identified as F. silvestris.

The presence of F. silvestris in Neolithic China supports the growing evidence of complex trade and exchange routes connecting western Asia to northern China perhaps as long ago as 5,000 years. However, Vigne et al. (2016) examined the evidence and believe that all the Chinese Neolithic period cats are not F. silvestris but rather leopard cat (Prionailurus bengalensis). Vigne et al. suggest that the leopard cat became a commensal species beginning in the mid-sixth millennium BP, evidence of a separate cat domestication event.

Breeds and Varieties and Tabbies

Today there are between 40 and 50 recognized cat breeds, which humans created by artificial selection for aesthetic traits they preferred, such as body and facial forms, beginning about 150 years ago. The traits selected by cat breeders include coat color, behavior, and morphology--and many of those traits are shared across breeds, meaning they were descended from the same cats. Some of the traits are also associated with deleterious genetic traits such as osteochondrodysplasia affecting the development of cartilage in Scottish Fold cats and taillessness in Manx cats.

The Persian or Longhair cat has an extremely short muzzle with large round eyes and small ears, a long, dense coat, and a round body. Bertolini and colleagues recently found that candidate genes for the facial morphology may be associated with behavioral disorders, susceptibility to infections, and breathing issues.

Wildcats exhibit a striped coat coloration pattern referred to as mackerel, which in many cats appears to have been modified to the blotched pattern known as "tabby". Tabby colorations are common in many different modern domestic breeds. Ottoni and colleagues note that striped cats are commonly illustrated from the Egyptian New Kingdom through the Middle Ages. By the 18th century AD, the blotched tabby markings were common enough for Linnaeus to include them with his descriptions of the domestic cat.

Scottish Wildcat

The Scottish wildcat is a large tabby cat with a bushy black ringed tail that is native to Scotland. There are only about 400 left and are thus among the most endangered species in the United Kingdom. As with other endangered species, threats to the wildcat's survival include habitat fragmentation and loss, illegal killing, and the presence of feral domestic cats in wild Scottish landscapes. This last leads to interbreeding and natural selection resulting in the loss of some of the characteristics which define the species.

Species-based conservation of the Scottish wildcat has included removing them from the wild and placing them into zoos and wildlife sanctuaries for captive breeding, as well as the targeted destruction of feral domestic and hybrid cats in the wild. But that reduces the number of wild animals even further. Fredriksen )2016) has argued that the pursuit of "native' Scottish biodiversity by attempting to stamp out "non-native' feral cats and the hybrids reduces the benefits of natural selection. It may be that the best chance the Scottish wildcat has of surviving in the face of a changing environment is to breed with domestic cats who are better adapted to it.

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