circa 7,300 -- 7,000 BC: The trend continues almost five thousand years later when tribes in the British Isles, and later the Greeks, begin to keep dogs.
circa 3,500 BC: The domestication of animals, including goats, sheep, asses, cattle, pigs, horses, and dogs -- combined with the invention of the wheel and the development of irrigation -- has streamlined food production enough to allow a few people to engage in scholarly, spiritual, aesthetic, and economic pursuits.
circa 3,000 BC: Following the invention of granaries in Egypt, wild cats are allowed indoors to hunt mice, beginning the evolution of the large, ferocious feline into our much smaller, yet ever willful, houseguests.
circa 2,850 BC: The Great Sphinx is created.
circa 2,000 BC: Egyptian hieroglyphics depicting exotic menageries of birds -- including doves, parrots, and ducks -- chronicle the beginnings of birdkeeping.
circa 0 AD: Jesus Christ is, reportedly, born in a manger, surrounded by humble animals.
circa AD 500 -- AD 1800: Pets were not uncommon in Europe during the Middle Ages and the Renaissance, but they were kept for the most part by courtiers, members of privileged religious orders, and the upper classes.
circa 1500 AD: The word pet, which is probably related to petty (small), is introduced into English as a reference to 'an animal kept as a favorite.'
19th century: As human dependence on animals decreases, Victorians become increasingly sentimental about horses and dogs. Intelligence, character, and even human forms of morality are attributed to them.
1851: The word 'doggone' first appears in print in the novel Scalp Hunt. It is generally taken as a deformation of the profanity 'God damn,' though its original form is thought to be 'dog on it,' to be used like 'pox on it.'
1865: Lewis Carroll publishes Alice's Adventures in Wonderland, and no one ever again looks at cats, mice, and rabbits without a touch of uneasiness.
circa 1870: Actress Sarah Bernhardt loses both her pet tortoise Chrysag?re and its 'servant,' a smaller tortoise named Zerbinette, to a devastating fire in her Paris flat.
1877: English author Anna Sewell writes Black Beauty. She is paid a flat 20 pounds for the manuscript and receives no royalties from what is to become a worldwide best-seller.
1884: Ten sportsmen in the United States form the American Kennel Club, an offshoot of England's Kennel Club, which was founded in 1873 to regulate the growing 'dog show' industry.
1894: The Robinson-Danforth Commission Co. is founded. In 1902 the company changes its name to Ralston Purina, makers of dog, cat, horse, and parrot 'chow.'
1926: Christopher Robin befriends his stuffed bear in the Winnie the Pooh stories, the forerunners of many commercially successful stuffed-animal fantasies. Pet historian Paul Shepard, identifies Winnie the Pooh with the advent of a new imaginative wilderness for children growing up in isolated suburban homes with few neighbor children to play with and little 'wild' to explore.
1928: Buddy, a German shepherd, becomes the first Seeing Eye dog.
1931: Mickey Mouse and Felix the Cat premiere in comic strips.
1939: A raggedy mutt named Toto charms the world as Dorothy's companion in MGM's film version of The Wizard of Oz.
1943: The first Lassie, played by a dog named Pal, co-stars with Elizabeth Taylor in the film Lassie Come Home -- the beginning of America's obsession with collies.
1945: George Orwell's Animal Farm and E.B. White's Stuart Little offer extremely different takes on anthropomorphized animals. White hits again in 1952 with Charlotte's Web, an animal story loved by children everywhere.
1949:The Lone Ranger airs on U.S. television. Central to the story is the uncanny connection between the Lone Ranger and his horse, Silver .
1951: Ronald Reagan raises a chimpanzee in Bedtime for Bonzo.
1956: Fred Gibson's Old Yeller tells the tale of a boy and his dog one year before the Russians shoot the dog Laika into space.
1961: Disney's 101 Dalmatians is filmed. (Thirty-plus years later, it will be the seventh-highest grossing film of all time.)
1963: Inventor Samuel Andrisani patents his Animal Toilet Garment to eliminate deposits of animal waste in public places. A secondary benefit as a birth control device should have guaranteed its place in the market, but somehow the garment never really takes off.
1968: The band Three Dog Night is formed and subsequently makes 21 trips to the charts between 1969 and 1975. The name refers to an Australian aborigine description of a night so cold that you have to sleep with three dogs to keep warm.
1969:Sesame Street, the home of 'Big Bird' and other puppet animals, goes on the air.
1976: Sylvester and Tweety finally get their own TV show, giving viewers a close look at what their pets do when no one is around.
1981: Minosch, a German cat, reportedly travels 1,500 miles in 61 days to get home after being separated from its vacationing family.
1988: The Potbellied Pig Registry is created to track the bloodlines of the new 'yuppie puppy.' By 1995 the registry has tracked 23,000 pigs, but experts estimate that there could be as many as 1 million pet pigs living in the U.S. Many humans find these large pets hard to live with.
1993: Americans spend $17 billion on pet food, supplies, and care.
1994: 2,132 people -- two-thirds women and one-third men -- graduate from schools of veterinary medicine in the U.S. By 1995 there will be approximately 40,300 vets in private practice in the U.S.
1995: Cats officially become the most popular and populous pet in the U.S., outnumbering dogs 63 million to 54 million. Despite work by animal rights groups, an estimated 20 million cats and dogs are euthanized.
1996: Estimates predict that 25 million animals will die in publicly funded experiments during the year.