Small-Scale Migrations among Early Farmers in the Sonoran Desert

Abstract Migration played a significant role in shaping the Native populations of the southwest United States and northwest Mexico. Large-scale migrations into and across the region were underlain by small-scale (intraregional) population shifts affected by environmental fluctuations (declines and improvements) and social phenomena such as aggregation and the spread of sociopolitical spheres of influence within the region. We compare projectile point types, mortuary patterns, and biodistance information from Early Agricultural period (2100 BC–AD 50) sites to identify subtle differences in population composition associated with the arrival and spread of maize across the region. Small-scale migrations occurring around the foundation of farming communities in the Sonoran Desert may have established the basis of broad regional connectivity, shared historical ties, and subsequent migration patterns and practices. Rooted in early farming traditions and a shared language family, we argue that farmers expanded north and east from the borderlands, then eventually returned to ancestral homelands when environmental and incursive pressures pushed them back south.