To examine the climate of the mid-Holocene and early human settings in the Andes when the Altiplano was recording the most arid phase of the Holocene, we analyzed plant-related proxies (pollen, phytoliths, diatoms, stable isotopes) from a sediment core sampled at high elevation in the Eastern Cordillera of Bolivia. Our study was carried out in the wetland of Tiquimani (16°12′06.8″S; 68°3′51.5″W; 3760 m), on a well-known pathway between Amazonia and Altiplano. The 7000-year old record shows a two-step mid-Holocene with a dry climate between 6800 and 5800, followed by a wetter period that lasted until 3200 cal. yr BP. In the Central Andes of Bolivia, a widespread aridity was observed on the Altiplano during the mid-Holocene. However, here, we show that moisture was maintained locally by convective activity from the Amazon lowlands. During the arid interval between 5000 and 4000 yr BP, these niches of moisture produced specific grasslands that may have enabled the survival of an archaic culture of hunter–gatherers on the Puna. This development occurred 2000 years before expansion of quinoa cultivation on the Puna.

Simple yet extensive landscape modifications made past agrarian societies resilient to climate change.

Here, we assess the extent to which land use relating to food acquisition (farming, herding, foraging) and associated value regimes shaped past economic inequality. We consider the hypothesis that land-use systems in which production was limited by heritable material wealth (such as land) sustained higher levels of inequality than those limited by (free) human labor. We address this hypothesis using the Global Dynamics of InequalIty (GINI) project database, estimating economic inequalities based on disparities in residential unit area and storage capacity within sites in different world regions and through time. We find that inequality was significantly greater in land-limited than labor-limited regimes, whether based on residence area or storage capacity, though governance could moderate these differences. Increasing inequality with larger residence and/or site size is associated with underlying shifts from labor- to land-limited economies. Transitions from labor- to land-limited regimes also appear to underlie the development of extended political hierarchies. Increases in inequality after cultivation became common in each hemisphere similarly reflect shifts from labor- to land-limited systems. Land-limited systems in the eastern hemisphere, incorporating animal traction, exhibit an upward trend in inequality over time, while a downward trend in the western hemisphere reflects the lower persistence of land-limited regimes based solely on human labor.

En este trabajo se presentan y se analizan los resultados alcanzados en el sector metalúrgico del sitio Pulac 050 (Escaramayu, Pulacayo, Bolivia). Los estudios desarrollados en el sector han puesto en evidencia un complejo de cuatro hornos metalúrgicos, los cuales se encuentran espacialmente asociados con un conjunto de recintos fechados en el Horizonte Medio. Restos de varios materiales incluyendo escorias, metales y minerales fueron encontrados junto a los hornos. Los análisis de isótopo de plomo de estos materiales sugieren fuertemente que la mena fundida en el sitio fue obtenida del depósito polimetálico de plomo, plata, cobre y zinc, de Pulacayo. Tres de los hornos parecen haber sido utilizados para fundir menas metálicas; mientras que el cuarto horno se usó para refinar, quizás, el metal impuro contenido dentro de crisoles de cerámica.