Within five years woolly mammoths may roam the Earth once again, reports Discovery News' Jennifer Viegas. Researchers in Russia recently found a mammoth thigh bone with well-preserved bone marrow and they are now analyzing it to see if there's enough DNA to clone the big, shaggy beast. The director of the Sakha Republic's mammoth museum in Siberia, Semyon Grigoriev, and his team are working with researchers from Japan's Kinki University to recreate the mammoth, Viegas says.