Copyright © 1998 by McGraw-Hill, Inc. All rights reserved. Printed in the United States of America. The entire contents or parts of this Update may be reproduced for use with Physical Anthropology, Sixth Edition, or Physical Anthropology: The Core, second edition, by Philip L. Stein and Bruce M. Rowe, provided each reproduction bears the copyright notice. The publisher's written permission must be obtained for other use.
See Physical Anthropology, 6th edition, Chapter 14, page 344; Physical Anthropology: The Core, 2nd edition, Chapter 9, page 212.
Perhaps the most difficult part of writing this report was coming up with a cleaver title. We must in all honestly recognize the best attempt as that which appeared in the July 18, 1998, issue of Science news: "Paleoscatology: Prying DNA from Dated Dung."
There is a form of evidence of prehistoric life that we rarely hear of; yet when available, this form provides important information about ancient life. Fossilized dung or coprolites are known from a large range of animals, including the dinosaurs. Another form is desiccated dung, in which organic material remains after thousands of years, just waiting to be analyzed. Recently, a method was developed for the analysis of DNA in desiccated dung. The sample tested was from a 20,000-year-old ground sloth, Nothrotheriops shastensis, from Gypsum Cave, located about 30 kilometers east of Las Vegas, Nevada.
DNA from a dung sample comes from three sources: cells shed from the intestinal wall of the animal, cells from the ingested plants consumed by the animal, and parasites residing in the intestinal tract. DNA from the cells of the ground sloth and from a number of plants were identified along with visual identification of fragments of plant material. Among the plants distinguished were grasses, yucca, grapes, and mint. Contemporary members of some of these genera are found today growing in high-elevation desert scrub habitats above 1370 meters. Since Gypsum Cave is located at 580 meters, this suggests that the climate was significantly cooler 20,000 years ago when the ground sloth crept into the cave and left a sample.
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Reference: H. N. Poinar et al., "Molecular Coproscopy: Dung and Diet of the Extinct Ground Sloth Nothrotheriops shastensis," Science, 281 (17 July 1998), 402-406.