Earliest evidence of humans on horses

New evidence dates domestication of horses to as early as 3500 BC

source:New Scientist 14 March 2009 vol 201 no 2699 p14

New evidence of early horse domestication has been found by Alan Outram and his team from the University of Essex, England. The team has discovered horse bones in four settlements of the Botai people in Kazakhstan. The bones have been dated to 3500 BC, 1000 years earlier than the previous earliest findings. Studies of the horses' teeth show wear of a kind indicating usage of bridles and bits. The team has also discovered equine milk fat traces on Botai pottery containers, which means that the Botai probably milked mares.
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