Carlos Aschero

Arqueología de las ocupaciones cazadoras-recolectoras de fines del Holoceno Medio de Antofagasta de la Sierra (Puna Meridional Argentina)

Resumen es: Se presenta una caracterizacion de las ocupaciones cazadoras-recolectoras del lapso ca. 5.500-3.000 anos a.p. en Antofagasta de la Sierra (Puna Meridiona...

Discontinuities in quinoa biodiversity in the dry Andes: an 18-century perspective based on allelic genotyping

History and environment shape crop biodiversity, particularly in areas with vulnerable human communities and ecosystems. Tracing crop biodiversity over time helps understand how rural societies cope with anthropogenic or climatic changes. Exceptionally well preserved ancient DNA of quinoa (Chenopodium quinoa Willd.) from the cold and arid Andes of Argentina has allowed us to track changes and continuities in quinoa diversity over 18 centuries, by coupling genotyping of 157 ancient and modern seeds by 24 SSR markers with cluster and coalescence analyses. Cluster analyses revealed clear population patterns separating modern and ancient quinoas. Coalescence-based analyses revealed that genetic drift within a single population cannot explain genetic differentiation among ancient and modern quinoas. The hypothesis of a genetic bottleneck related to the Spanish Conquest also does not seem to apply at a local scale. Instead, the most likely scenario is the replacement of preexisting quinoa gene pools with new ones of lower genetic diversity. This process occurred at least twice in the last 18 centuries: first, between the 6th and 12th centuries—a time of agricultural intensification well before the Inka and Spanish conquests—and then between the 13th century and today—a period marked by farming marginalization in the late 19th century likely due to a severe multidecadal drought. While these processes of local gene pool replacement do not imply losses of genetic diversity at the metapopulation scale, they support the view that gene pool replacement linked to social and environmental changes can result from opposite agricultural trajectories.

TECNOLOGÍA LÍTICA DEL PLEISTOCENO FINAL Y LA COLONIZACIÓN DEL SALAR DE PUNTA NEGRA (24,5º S), DESIERTO DE ATACAMA

SPN-1y SPN-6 son dos contextos arqueologicos ubicados en el margen noreste del salar de Punta Negra (24,5° S, 3.000 msnm),xa0que marcan un primer pulso de ocupacion humana en la puna delxa0Desierto de Atacama meridional (12.600-10.200 anos cal.AP).xa0A traves del estudio del registro litico, se reconstruyen las cadenasxa0operativas de talla y se discuten las estrategias tecnologicas implementadas. Se plantea que, en un escenario de dispersion inicialxa0a un paisaje arido, con recursos hidricos segmentados, los gruposxa0humanos habrian desarrollado un sistema tecnologico litico flexible, adaptado a una movilidad residencial en escalas espacialesxa0amplias. Esta idea es contrastada en cuatro aspectos centrales: 1)xa0el empleo de sistemas de desbaste de baja inversion tecnica, 2) laxa0existencia de cadenas operativas ramificadas, 3) una produccionxa0de soportes indiferenciados y 4) el retomado y reconfiguracionxa0sistematica de instrumentos.