A nomad is a member of people having no permanent abode, who travel from place to place to find fresh pasture for their livestock. The generic title encompasses the varied ethnic groups who have at times inhabited the steppes of Central Asia, Mongolia, and what is now Russia and Ukraine. They domesticated the horse around 3500 BCE, vastly increasing the possibilities of nomadic life, and subsequently their economy and culture emphasised horse breeding, horse riding and nomadic pastoralism; this usually involved trading with settled peoples around the steppe edges. They developed the chariot, wagon, cavalry and horse archery and introduced innovations such as the bridle, bit and stirrup, and the very rapid rate at which innovations crossed the steppelands spread these widely, to be copied by settled peoples bordering the steppes. During the Iron Age, Scythian cultures emerged among the Eurasian nomads, which was characterized by a distinct Scythian art.