The geographic and temporal origins of the domestic dog remain controversial, as genetic data suggest a domestication process in East Asia beginning 15,000 years ago, whereas the oldest doglike fossils are found in Europe and Siberia and date to >30,000 years ago. We analyzed the mitochondrial genomes of 18 prehistoric canids from Eurasia and the New World, along with a comprehensive panel of modern dogs and wolves. The mitochondrial genomes of all modern dogs are phylogenetically most closely related to either ancient or modern canids of Europe. Molecular dating suggests an onset of domestication there 18,800 to 32,100 years ago. These findings imply that domestic dogs are the culmination of a process that initiated with European hunter-gatherers and the canids with whom they interacted.

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

The projectile points known as Fishtail or Fell represent a specific design associated with the earliest hunter-gatherers of the Pleistocene-Holocene transition in South America. Brazil was traditionally considered as a marginal area of their distribution because in the past there were only a small number of findings known, often inadequately documented. In this paper we present a general and unified overview of the Brazilian record, including previously unpublished metric, technological and stylistic features. Also, we report on new findings of fishtail points in order to expand the amount of information currently available. Some issues related to these records are also evaluated by comparing them with data from the Uruguayan plains and the Argentinean pampas. The general picture that emerges after this analysis shows a growing record of fishtail projectile points in southern Brazil, demonstrating a significant presence of these early paleo-South American populations.

R e s u m e n Se analiza el primer registro confiable de un perro prehispánico (Canis familiaris) recuperado en un sitio de cazadores recolectores del humedal del Paraná inferior (Argentina). Se discuten distintos aspectos relacionados con su origen, antigüedad y tipo de interacción que habrían establecido con las poblaciones humanas en el marco de la escasa información de la que actualmente disponemos acerca de su presencia entre los grupos cazadores-recolectores del extremo sur de Sudamérica.