Genetic analysis reveals the wild ancestors of the llama and alpaca

KADWELL M.; FERNANDEZ M.; STANLEY H.F.; BALDI R.; WHEELER J.C.; ROSADIO R.; BRUFORD M.W.

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. SERIES B: BIOLOGICAL SCIENCES.

The Royal Society

Lugar: Londres; Año: 2001 vol. 268 p. 2575 - 2584

0962-8452

The origins of South America's domestic alpaca and llama remain controversial due to hybridization, near extirpation during the Spanish conquest, and difficulties in archaeological interpretation.  Traditionally, the ancestry of both forms is attributed to the guanaco while the vicuña is assumed never to have been domesticated.  Recent research has, however, linked the alpaca to the vicuña, dating domestication to 6 - 7,000 YA in the Peruvian Andes. Here we examine in detail the genetic relationships among the South American camelids to determine the origins of the domestic forms, using mitochondrial (mt) and microsatellite (STR) DNA.  MtDNA analysis places 80% of llama and alpaca sequences in the guanaco lineage, with those possessing vicuña mtDNA being nearly all alpaca or alpaca/vicuña hybrids.  However, since mtDNA is maternally inherited, we examined four STRs in wild, known provenance vicuña and guanaco, including two loci with non-overlapping allele size ranges in the two species.  In contrast to MtDNA, these markers show high genetic similarity between alpaca and vicuña, and between llama and guanaco, although evidence for bi-directional hybridization is also apparent.  Biparentally inherited marker evidence therefore suggests that the alpaca is descended from the vicuña, and should be reclassified as Vicugna pacos. This result has major implications for the future management of wild and domestic camelids in South America.