Pre-European Plant Consumption and Cultural Changes in the Coastal Lluta Valley, Atacama Desert, Northern Chile (Ca. 5140-390 Cal Yr BP). The introduction of domesticated plants into ancient hunting and gathering economic systems expanded and transformed human societies worldwide during the Holocene. These transformations occurred even in the oases and hyperarid environments of the Atacama Desert along the Pacific coast. Human groups inhabiting this desert incorporated adjacent habitats to the semi-tropical valleys through transitory or logistic camps like Morro Negro 1 (MN-1), in the Lluta valley (similar to 12 km from the littoral in northernmost Chile), into their settlement patterns. During the earliest occupation (Late Archaic period, 5140-4270 cal yr BP) people collected and consumed wild plants, although crops such as Lagenaria were present. Following a gap of more than 2000 years between 4270 and 1850, people returned and introduced new domesticated plants at the site (Gossypium, Zea mays, Capsicum), which displaced the use of wild reed (Schoenoplectus) rhizomes as the chief staple during the first occupation. This change in food consumption was linked to the transformations that took place during the Archaic-Formative transition, but did not entirely shift the ways of life of these coastal marine hunter-gatherers.