Battle of the clones: when will a replica horse win Olympic gold?

    Story highlights

    • Tomatillo, clone of eventing great Tamarillo, reaches 18 months old. Will he compete like his 'dad'?
    • Rules changed in 2012 to let clones compete in sport, but experts say focus on breeding for now
    • Two clones of Irish sporthorse sire Cruising revealed in February after years of speculation
    • Would an Olympic Games with every competitor on a clone of the same horse actually be a fairer contest?

    (CNN)To the untrained eye, Tomatillo looks like any horse.

    To those in the know, the 18-month-old looks like one horse.
      Tomatillo is the clone of Tamarillo -- a famous eventing horse who reached the Olympics in 2004.
        Twelve years have passed since humans first successfully cloned a horse. The science is developing fast, but remains imperfect.