A molecular analysis of ground sloth diet through the last glaciation
We extracted DNA from five coprolites dated between 11,000 years ago and 28,500 years ago all excavated in Gypsum Cave. All coprolites contained DNA identifying the defector as Shasta ground sloth. Amplification for the rbcL gene in chloroplast also shows that the environment at the end of the Pleistocene was much drier than it was in the past.
Jul 10, 2000
Authors: M. Hofreiter, H.N. Poinar, W.G. Spaulding, K. Bauer, P.S. Martin, G. Possnert and S. Pääbo
Molecular Ecology, Vol. 9, Issue 12, December 2000, pp. 1975–1984. DOI: https://doi.org/10.1046/j.1365-294X.2000.01106.x
Abstract
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.