>> cambiaso: yes. >> stahl: but the horse could not be saved. before they put him down, adolfol decision. he asked his veterinarian to save some of the horse's skin cells. he thought that one day, he could bring aiken cura back to life through cloning. >> cambiaso: i was really sad, and i say cloning should work-- >> stahl: how did that come into your head? >> cambiaso: i don't know. i decided to keep some cells from him, just in case, years later, cloning is normal. >> stahl: he remembered dolly the sheep, the first cloned mammal. since then, scientists have cloned cows, pigs, goats, and in 2003, the first horse. biologist adrian mutto, one of the first scientists to clone in argentina, showed us the process: he starts with an egg extracted minutes earlier from a mare. >> adrian mutto: you can see here, this is an egg. and with that needle, we eliminate all d.n.a. of each egg. >> stahl: next, he replaces it with the d.n.a. of the horse they want to clone. >> mutto: the next step is introduce again into the, into the egg, the needle. this is the d.n.a. into the egg. >> stahl: y