Mitochondrial DNA sequences isolated from ancient dog remains from Latin America and Alaska showed that native American dogs originated from multiple Old World lineages of dogs that accompanied late Pleistocene humans across the Bering Strait. One clade of dog sequences was unique to the New World, which is consistent with a period of geographic isolation. This unique clade was absent from a large sample of modern dogs, which implies that European colonists systematically discouraged the breeding of native American dogs.

The origins of South America's domestic alpaca and llama remain controversial due to hybridization, near extirpation during the Spanish conquest and di¤culties in archaeological interpretation. Traditionally, the ancestry of both forms is attributed to the guanaco, while the vicu·a is assumed never to have been domesticated. Recent research has, however, linked the alpaca to the vicu·a, dating domestication to 6000^7000 years before present in the Peruvian Andes. Here, we examine in detail the genetic relationships between the South American camelids in order to determine the origins of the domestic forms, using mitochondrial (mt) and microsatellite DNA. MtDNA analysis places 80% of llama and alpaca sequences in the guanaco lineage, with those possessing vicu·a mtDNA being nearly all alpaca or alpaca^vicu·a hybrids. We also examined four microsatellites in wild known-provenance vicu·a and guanaco, including two loci with non-overlapping allele size ranges in the wild species. In contrast to the mtDNA, these markers show high genetic similarity between alpaca and vicu·a, and between llama and guanaco, although bidirectional hybridization is also revealed. Finally, combined marker analysis on a subset of samples con¢rms the microsatellite interpretation and suggests that the alpaca is descended from the vicu·a, and should be reclassi¢ed as Vicugna pacos. This result has major implications for the future management of wild and domestic camelids in South America.

This paper provides a review of South American camelid evclution, classification and present status. Particular attention is paid to the debate roncerning origins of the domestic alpaca and llama and the contribution of researrh on faunal remains from Andean archaeological sites towards resolving this issue. Changes in incisor morphology during the domestication process suggest that the alpaca may be descended from the vicuiia, while a comparison of fibre production characteristirs in preconquest and extant llama and alpaca breeds indicates that extensive hybridization hetwern the two species is likely to have occurred since European contact. The potential role of hybridization in the formation of extant South American camelid populations has not been studied, and may be the root cause of taxonomic disputes.

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Patagonian megafaunal extinctions reveal synergistic roles of climate change and human impacts.