The horse is a large mammal belonging the genus Equus. The creature can be used to ride on, especially in sports such as equestrianism and polo, to carry goods and for transport. All modern horses are descended from ancestors that lived in North America. The horse was first domesticated at around 4000 BC by a tribe living on the plains of Central Asia. A few remnant wild populations of horses still thrive on the plains of North America and Asia as well as introduced populations in Australia, while their domesticated bretherin are tamed in many parts of the world.