The cat that walked by itself

An animal that took up with people on its own terms, and what follows from that

A The relationship between people and cats is the least deliberate of the domestications, and possibly the least complete. Every other domesticated animal was pursued: taken, confined, fed and bred by people who wanted something specific from it. The cat appears in the record without any evidence of that process, in a form barely distinguishable from its wild ancestor, and the most defensible account is that it domesticated itself by exploiting an opportunity people had created without intending to.

B The absence of intention is not merely a gap in the evidence. Every element of the process can be accounted for without anyone deciding anything, which is a stronger claim than saying we do not know who decided. The opportunity was grain. Settled agriculture produces stored surpluses, stored surpluses attract rodents, and concentrations of rodents attract a small solitary predator that hunts them. The wildcat of the Near East, from which every domestic cat descends, was already suited to the role: it hunts alone, tolerates other individuals when food is abundant, and is small enough to pose no threat to people. Those wildcats that could tolerate human proximity ate better than those that could not, and the tolerance was heritable. Nobody selected anything. The village supplied the conditions and the animals sorted themselves.

C The archaeological evidence supports this timing and pushes it earlier than the familiar Egyptian material. A grave on Cyprus, dated to about nine and a half thousand years ago, contains a human burial with a cat interred beside it, arranged deliberately. The significance is geographical as much as ceremonial: there were no cats native to the island, so this one arrived by boat with people who had reason to bring it, several thousand years before the Egyptian evidence usually treated as the beginning of the story.

D What genetics has added is mainly a negative. The domestic cat differs from the Near Eastern wildcat far less than a dog differs from a wolf, or a cow from an aurochs; the genes that do differ are associated with tameness, with the reward pathways involved in tolerating people, and with coat colour, and they are few. The blotched tabby pattern now regarded as ordinary appears in the record only in the medieval period, which means the visible marker most people would use to identify a domestic cat is younger than the domestication by some eight thousand years.

E The behavioural evidence is more ambiguous than owners tend to assume. Cats discriminate their own name from similar words, respond to human emotional expression and form attachments to particular people that resemble those of dogs and infants in the standard experimental paradigm. They also survive perfectly well without people, revert to independence within a generation or two, and breed freely with wildcats wherever the two overlap — which is why the wildcat populations of Europe are now genetically compromised almost everywhere they persist. That last fact is worth dwelling on, because it means the two forms have never separated in the way that domestic and wild forms of other species have; there is a continuous exchange of genes between the domestic animal and the wild one, and in several countries the wild form is disappearing not by being killed but by being absorbed. An animal that can leave and does not is in a different relationship from one that cannot.

F The argument about whether this counts as domestication is partly semantic and partly substantive. On a strict definition requiring human control of breeding, the cat qualifies only for the small proportion of pedigree animals bred in the last hundred and fifty years, which is a trivial fraction of the world's cats. On a definition emphasising adaptation to a human-created niche, it qualifies completely and did so before most of the animals whose domestication is undisputed. The disagreement is not really about cats; it is about whether domestication describes what people did to an animal or what an animal became.

G The practical stakes are considerable, because a semi-domesticated small predator distributed worldwide in enormous numbers has ecological effects that a fully dependent animal would not. Cats hunt when they are fed, since hunting is not driven by hunger, and the resulting toll on birds, reptiles and small mammals is very large in aggregate and has been implicated in island extinctions in particular. The responses proposed range from confinement to systematic removal, and they divide people who agree about the ecology and disagree about the animal's status. The question of what the cat is turns out to be an unusually direct route to the question of what is owed to it.