Subsistence adaptations respond to environmental instability as well as sociopolitical demands. On the Andean altiplano, camelid husbandry is a key adaptation utilized for thousands of years to mitigate environmental risks to agricultural productivity, to facilitate transport and to generate wealth for political purposes. Here, we reconstruct the history of camelid utilization on the altiplano with fecal stanol biomarkers from Lake Orurillo in southern Peru. Biomarker samples span a 4000-year interval and document changes at centennial timescales. The abundances of individual fecal stanols appear to be less diagnostic of changes in human occupation in the Orurillo region where human population levels apparently remained far lower than those of domesticated camelids. However, ratios of human (coprostanol) to ruminant (24-ethylcoprosanol) fecal stanol concentrations demonstrate that these proxies are reliable indicators of variations in camelid herd sizes. Our data show that camelid utilization intensified after ca. 1050 CE during a severe and protracted drought that was coincident with widespread population movement away from fertile farmlands to higher elevations favorable for grazing. Camelid herds remained in high abundance around Orurillo during improved climate conditions and through the Inca era until after ca. 1500 CE when our data point to a significant disruption after European conquest. The intensification of camelid husbandry among Andean cultures is therefore linked to major environmental and sociopolitical shifts.

生存适应应对环境不稳定以及社会政治需求。在安第斯高原，骆驼畜牧业是数千年来用于减轻农业生产力的环境风险、促进运输和为政治目的创造财富的关键适应性。在这里，我们重建了高原骆驼科动物利用的历史来自秘鲁南部奥鲁里洛湖的粪便甾烷醇生物标志物。生物标志物样本跨越 4000 年，并记录百年时间尺度的变化。个体粪便甾烷醇的丰度似乎不太能诊断奥鲁里洛地区人类职业的变化，那里的人口水平显然远低于驯化的骆驼科动物。然而，人类（粪前列醇）与反刍动物（24-乙基coprosanol）粪便甾烷醇浓度的比率表明，这些代理是骆驼群大小变化的可靠指标。我们的数据显示，在大约之后，骆驼科动物的利用加剧了。公元 1050 年，在一场严重而持久的干旱期间，恰逢人口从肥沃的农田转移到有利于放牧的高海拔地区。在气候条件改善期间，直到印加时代，奥鲁里洛周围的骆驼群仍然保持高丰度。公元 1500 年，我们的数据表明欧洲征服后发生了重大破坏。因此，安第斯文化中骆驼畜牧业的集约化与主要的环境和社会政治变化有关。