DNA was extracted from five coprolites, excavated in Gypsum Cave, Nevada and radiocarbon dated to approximately 11 000, 20 000 and 28 500 years BP. All coprolites contained mitochondrial DNA sequences identical to a DNA sequence determined from a bone of the extinct ground sloth Nothrotheriops shastensis. A 157-bp fragment of the chloroplast gene for the large subunit of the ribulosebisphosphate carboxylase (rbcL) was amplified from the boluses and several hundred clones were sequenced. In addition, the same DNA fragment was sequenced from 99 plant species that occur in the vicinity of Gypsum Cave today. When these were compared to the DNA sequences in GenBank, 69 were correctly (two incorrectly) assigned to taxonomic orders. The plant sequences from the five coprolites as well as from one previously studied coprolite were compared to rbcL sequences in GenBank and the contemporary plant species. Thirteen families or orders of plants that formed part of the diet of the Shasta ground sloth could be identified, showing that the ground sloth was feeding on trees as well as herbs and grasses. The plants in the boluses further indicate that the climate 11 000 years BP was dryer than 20 000 and 28 500 years BP. However, the sloths seem to have visited water sources more frequently at 11 000 BP than at earlier times.

Poinar HN. DNA from fossils: the past and the future. Acta Paediatr 1999; Suppl 433: The recovery of DNA from archaeological and palaeontological remains has intrigued scientists for many years. The DNA molecule is a relatively weak molecule compared with other biomacromolecules in tissues, but the sequence of its bases holds insights into questions that cannot be resolved by standard palaeontological methods. Recent advances in the field, such as the recovery of DNA sequences from coprolites found in the southwestern USA, as well as from the Neanderthal-type specimen, have shed new light on populations that are now extinct. A better understanding of how DNA is preserved in fossils, as well as the use of novel agents that can release the DNA from archaeological and palaeontological materials, will likely lead to new successes in the field. The analysis of ancient DNA may provide new clues about human evolution and answer questions, for example, relating to the diversity of the Neanderthals and the mammoths. 0 Ancient DNA, Ice Man, Neanderthal, DNA preservation HN Poinar,