Blast from the ancient past
German biologists have extracted and sequenced deoxyribose nucleic ! acid {DNA) from 20,000-year-old dung found in a cave near Las Vegas, USA. Biochemist Hendrik Poinar and his colleagues at the University of Munich, Germany, used the DNA sequences to identify the source of the dung. They claim it is the Shasta ground sloth, now extinct for an esti-mated 11,000 years. Although diges-tion had split the DNA into chains of no more than a mere 300 base pairs, Poinar and his team were still able to distinguish sloth sequences from the DNA in its food.