Portal de Periódicos da CAPES

ANCIENT DNA EVIDENCE OF PROLONGED POPULATION PERSISTENCE WITH NEGLIGIBLE GENETIC DIVERSITY IN AN ENDEMIC TUCO-TUCO (CTENOMYS SOCIABILIS)

2003; Oxford University Press; Volume: 84; Issue: 2 Linguagem: Inglês

10.1644/1545-1542(2003)084 2.0.co;2

1545-1542

Elizabeth A. Hadly, Marcel van Tuinen, Yvonne L. Chan, Kimberly W. Heiman,

Wildlife Ecology and Conservation

We traced a population of Ctenomys sociabilis, a highly endemic South American tuco-tuco, through 1,000 years to assess its response to climatic change and recent human disturbance. Samples were obtained from a late-Holocene raptor roost in Parque Nacional Nahuel Huapi, Argentina, which produced a diverse and abundant rodent fauna, with >10 genera extending from the present to 950 ± 50 years ago (CAMS-45936). The site (Estancia Nahuel Huapi locality 1) was located near the center of the present geographic range of C. sociabilis, which occurs throughout 8 of 9 stratigraphic levels in the site. To examine genetic structure through time, we extracted ancient DNA from 16 teeth at those levels and from 1 modern tooth at the surface for a total of 17 specimens. Cytochrome-b sequences from ancient and modern specimens were compared with a modern tuco-tuco sequence from the extant local population. Our results show that of those 17 specimens, all but 1 had identical sequences. Further, these sequences were identical to a representative of the modern population. Thus, that population has remained genetically identical for at least 1,000 years in the face of climatic change, human disturbance, and proximity of other tuco-tuco species (C. haigi, C. maulinus) with adjacent geographic distributions. Our findings indicate that a population bottleneck contributing to low genetic diversity of C. sociabilis occurred before 1,000 years ago and that late-Holocene climatic change occurred without a corresponding impact on the genetic diversity of this species.