DNA

The traditional route to DNA in ancient samples is through bones and preserved muscle, but any genetic material usually falls apart very soon after death and is prone to contamination from bacteria.
"There are also a lot of old bison and horse mummies turning up in the permafrost. It's not just animals, there are humans [too]; there are a lot of mummies around the world with hair, ranging from Egypt, South America to the more cold, better-preserved ones in Greenland."

Asked the classic question about whether it would be possible to clone any extinct creatures back into existence, Dr Gilbert said that even if the full genetic sequence of a mammoth could be retrieved, the technology did not currently exist to turn that biochemical information into a live animal.

The six-month-old female mammoth calf was discovered on the Yamal peninsula of Russia and is thought to have died 10,000 years ago.
The animal's trunk and eyes are still intact and some of its fur remains on the body. "The mammoth has no defects except that its tail was bit off," "In terms of its state of preservation, this is the world's most valuable discovery," That specimen failed to yield DNA of sufficient quality,
One population of mammoths lived on in isolation on Russia's remote Wrangel Island until about 5,000 years ago – may be 4000 years ago. …radiocarbon dated to be no more than 3,700-7,000 years old.
Several full-body mammoths have been found in the past, "But none of them has been excavated and preserved in a perfect condition... as frozen bodies start to rot the moment they come out of ice,"
DNA, a notoriously unstable molecule …

So who DO we believe ? The Scientist who was not alive more than 100 years ago or the man, people, who said he, they, saw mammoth a hundred years ago ??
I remember something like this once before. When they were working for King James the Bible translators opted to go with the scientists, rocks do not fall out of the sky ! Every thing that falls out of the sky in the KJV Bible is hail.