The earliest evidence of horse domestication is in Kazakhstan, where villages of the Botai culture show that 5500 years ago, previously nomadic peoples were living in permanent settlements of up to a thousand residents with economies based completely on the horse.
Dr. Sandra Olsen, Curator of Anthropology at the Carnegie Museum of Natural History, says evidence from excavations shows the Botai milked their horses, ate them, rode them and sacrificed them to a sun god, besides using their manure for insulation and roofing.
Olsen's research is highlighted in today's issue of the journal Science and in "The Horse", an exhibit at the Carnegie until May 24th. She says the exhibit shows the horse is the most important domesticated animal because of the varied roles it has played in human history. A video in the exhibit shows the use of horses in yet a new role: equine therapy for physically handicapped riders.