Day et al.  made a provocative proposal: that complex societies evolved in response to the increased productivity of coastal marine ecosystems following sea level stabilization (SLS). Although the known record of complex societies does roughly coincide with SLS, neither the linkage to increased marine productivity nor the assertion that complex societies emerged at that time is warranted.
Although increased marine productivity would have influenced coastal societies, the most prominent early societies (e.g., Nile, Mesopotamia, Indus, Yellow) relied primarily on riparian grain production. Coeval Mississippi Valley society was centered more than 300 kilometers inland and relied on riverine resources (freshwater fish and so forth) [Saunders et al., 2005]. These are the societies that apparently first constructed permanent structures (temples, permanent buildings, mound systems).