Between 13,000 and 2,500 B.C., humans domesticated dogs, cats, cattle, goats, horses, and sheep from their wild counterparts. Although the terms "taming" and "domestication" are often used interchangeably, they are not the same. Individual wild animals can be tamed to behave in a docile manner around humans. By contrast, domestication is a process that takes place with an entire animal species over many generations.
Characteristics of Domesticated Animals
Domesticated animals are not just tamer than their wild ancestors; they are different genetically. Over the ages, desirable qualities, such as size and disposition, were engrained by breeding only those animals that displayed them. This explains some of the physical differences between wild and domesticated animals. For example, most domesticated species are smaller and fatter and have smaller teeth and brains than their wild ancestors. (See Figure 1.2.)
In his article "Evolution, Consequences, and Future of Plant and Animal Domestication" (Nature, August 8, 2002), Jared Diamond described the biological traits and behaviors that wild animals must have to be domesticated. Successful domestication is only possible with species that exhibit these characteristics:
- A diet that can be supplied easily and relatively cheaply by humans
- A relatively fast growth rate with short time intervals between births
- The ability to mate and breed in captivity
- A tendency toward calm, predictable behavior rather than panic
- A lack of viciousness toward humans
- A social structure based on hierarchy and cooperative group living without strong territorialism
If any one of the characteristics is missing, the species cannot be domesticated. According to Diamond, only fourteen of the 148 species of large land-based mammals have been domesticated.
Domestication of Dogs and Cats
The dog is thought to have been the first animal to be domesticated by humans, sometime around 13,000�10,000 B.C., from its wolf-like ancestor Canis lupus. Scientists believe that humans either adopted cubs and
Domestic farm animals and their ancestors
SOURCE: "Domestic Farm Animals and their Ancestors," in What Is Animal Domestication? University of Saskatchewan, College of Agriculture, January 29, 1999, http://ag2.usask.ca/in_the_community/displays/what/animdom.html(accessed March 11, 2005)
raised them or just began to accept into their groups some of the less fierce wolves that hung around their camps scrounging for leftovers. In either event, humans soon found dogs to be a welcome addition. The arrangement benefited both sides, as domesticated wolves helped humans with hunting and guarding duties and shared the food that was obtained.
Although cat remains have been found in settlements that date back to 8,000 B.C., it is not clear if these were domesticated cats or small wild cats that were tolerated by or even encouraged to live near the people living there. Cat bones mixed with human and rat bones found on the island of Cyprus date back to around 5,000 B.C. Because wild cats are not native to the island, cats must have been transported there by humans on purpose, probably to control the rat population.
The ancient Egyptians are usually credited with domesticating wild cats (Felis silvestris libyca, originating in Africa and southwestern Asia) around 4,000 B.C. The Egyptians most likely raised cats from small kittens to protect their grain stores from rats and mice. Cat domestication is strongly associated with the establishment of permanent settlements and the growing and storage of grains. Cats became important to agricultural societies, just as dogs had been important to hunting cultures.
Domestication of Livestock
The domestication of livestock�chiefly pigs, cows, sheep, horses, and goats�is thought to have occurred between 9,000 and 5,000 B.C. as agriculture became more of a factor in human societies scattered across Asia and Europe. Scientists can estimate these dates based on evidence from excavated archaeological sites.
The study of historical human-animal interaction is called archaezoology or zooarchaeology. The age, sex, and condition of animal remains found near human settlements provide many clues. Any evidence of sharp knife marks on animal bones indicates that an animal was killed and consumed by humans, not another predator.
Sites associated with hunters feature the bones of mostly large adult male animals. These animals would have been the preferred targets because they provided more meat than younger males or females. By contrast, agricultural sites are more likely to contain the bones of younger, smaller male animals than those of older larger males. Herd management (then and now) involves keeping mostly female animals. A few large males with desired qualities are kept alive for breeding purposes, but most males are slaughtered at a relatively young age. Likewise, when animal bones indicate that a group of animals died at about the same age, this is a strong indication that these animals were domesticated, not wild.
The domestication of pigs, cows, oxen, sheep, goats, and horses all occurred in a relatively short period of time. Although there is disagreement about the order in which these animals were domesticated, many scientists believe that the pig was first, domesticated from wild boars. (See Figure 1.2.) Cows and oxen descend from aurochs, large and fierce wild animals that later became extinct. Sheep and goats were domesticated from their wild counterparts and selectively bred to provide desired coat and meat characteristics. Most historians believe that dogs played an invaluable role in helping humans to herd and control these animals and protect them from wild predators.
Horses are thought to have been domesticated around 6,000 B.C. Archaeological evidence indicates that they were first herded for their meat, hides, and milk. Horse milk was fermented into an alcoholic brew called kummis by ancient peoples living in central Asia. As the growing of crops became more important, horses and oxen became more useful as work animals, pulling carts, wagons, and plows. The Egyptians began using horses to pull plows in the fields sometime after 4,000 B.C. Gradually, horses were trained for use in transportation and in warfare.
Donkeys are believed to descend from African wild asses. Domestic donkey remains have been found in Egyptian excavations dating back to around 4,000 B.C. Donkeys were probably first used as beasts of burden to supplement the work done by oxen, and later as riding animals. Horses and donkeys allowed people to become much more mobile than they had been, which led to increased trading among different cultures.
Chickens were domesticated from Asian jungle fowl around 3,500 B.C. as a source of meat and eggs. Camels were domesticated around 2,500 B.C. According to the Agropolis-Museum of France, other early domesticated animals were turkeys and musk ducks in Central America, and llamas, guinea pigs, and alpacas in South America.
Virtually no other animal species have been domesticated since around 2,500 B.C. Humans tried to domesticate many other types of animals that could be useful for work or provide a good meat source, but these attempts have been unsuccessful. Zebras are the most notable example. Ancient herdsmen tried for centuries to domesticate zebras. Although they are genetically very similar to horses and can even breed with horses, their behavior is quite different. Zebras are notoriously bad-tempered around humans and have never lost their tendency to bite unexpectedly.
Elephants have historically been used as work animals in some parts of the world, but they grow too slowly to become truly domesticated animals. Grizzly bears and African buffalo have never been domesticated, because of their unpredictable dispositions. Likewise, deer and antelope are unsuitable because they cannot be herded or penned up (with the exception of reindeer). They flee in panic when they are frightened and do not have the proper social structure for domestication.
History has shown that the most suitable animals for domestication (and use by humans) are those that naturally live in groups with a hierarchical social structure. This allows humans to assume a dominant role in the hierarchy and exert control over the animals' behavior. Of the animals that have been domesticated, only cats and ferrets are considered to exhibit solitary lifestyles rather than herd/group behavior. In fact, scientists are not convinced that all species of cats and ferrets are completely domesticated in the classic sense.
Domestication Frees Humans' Time
The domestication of livestock and the rise of human civilization occurred around the same time and are unmistakably linked. The ability to keep and control groups of meat-supplying animals allowed humans to give up their previously nomadic lives and produce excess food. This freed people to build cities and roads, invent new things, and cultivate the arts.