Dolly the sheep became famous two decades ago for being the first mammal to be successfully cloned. Today, four sheep that came from the same cells as Dolly have reached their ninth birthday. This is significant to scientists because it shows that it is possible for cloned mammals to live healthy lives into old age. Listen to hear more about this encouraging milestone for cloned animals.
Story Length: 3:29
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AIR DATE: 07/21/2016
