Goats may have deserved the title of being man's real best friend

The goat probably should have won the title as man's best friend. It holds pride of place as the first animal for which scientific evidence is available of early domestication by humans.

Scientists are slowly but surely tracking down the archaeological and genetic evidence which tells us how and when humankind first began to domesticate animals and plants. The latest discoveries were explained at the American Association for the Advancement of Science annual meeting in San Francisco.

The genetic code of modern animals carries with it a historical record of its origins, explained Dr Dan Bradley of the Department of Genetics at Trinity College Dublin. By analysing the code you can trace back to an animal's origins. "You can really start to read the genetic past."

The same holds true for genetic analysis of plant material, said Prof John Doebley of the College of Agriculture and Life Sciences at the University of Wisconsin. It can tell you about a plant's origins, where domesticated forms were first planted and where a food crop later spread.

Domestication of plants and animals "represents a partnership with humans that brings advantages to both", said Dr Melinda Zeder, director of the Zoo-archaeology Programme at the Smithsonian Institution in Washington.

Animals would probably have been chosen or "auditioned" on the basis of behaviour, with docility being a key initial consideration, she said. As human experience of animal domestication grew, so, too, did ambition in terms of size.

For this reason goats and sheep were the first to come under the control of humans, followed by cattle.

Subduing early feral cattle was quite a feat, Dr Bradley said, and was achieved about 8,500 years ago. "They were a large formidable beast. Caesar described them as big and dangerous."

This animal has died out, but its tamer relations live among us on farms today.

The research suggests that plant and animal domestication began about 10,000 years ago, said Dr Michael Smith, director of the archaeobiology programme at the Smithsonian.

Northern China produced the first domesticated millet while southern China brought an early rice into cultivation. The Fertile Crescent contributed wheat and possibly barley, and the sub-Sahara first produced African millet and sorghum.

In the Americas, the south central Andes delivered the potato and animals including the llama and the guinea pig. Southern Mexico cultivated beans, squash and corn.

The first animal to be domesticated was the goat, about 10,000 years ago in the Zagros mountains in the eastern Fertile Crescent of what is now Iran. A separate domestication took place in the Indus valley at about the same time.

Sheep followed with domestication in the Fertile Crescent and India or Pakistan, and then the pig, separately in the Near East and in China.

Scientists have evidence of when the goat was first domesticated, but not of the dog.