Genetic and anatomical evidence suggests that Homo sapiens arose in Africa between 200 and 100ka, and recent evidence suggests that complex cognition may have appeared between ~164 and 75ka. This evidence directs our focus to Marine Isotope Stage (MIS) 6, when from 195-123ka the world was in a fluctuating but predominantly glacial stage, when much of Africa was cooler and drier, and when dated archaeological sites are rare. Previously we have shown that humans had expanded their diet to include marine resources by ~164ka (±12ka) at Pinnacle Point Cave 13B (PP13B) on the south coast of South Africa, perhaps as a response to these harsh environmental conditions. The associated material culture documents an early use and modification of pigment, likely for symbolic behavior, as well as the production of bladelet stone tool technology, and there is now intriguing evidence for heat treatment of lithics. PP13B also includes a later sequence of MIS 5 occupations that document an adaptation that increasingly focuses on coastal resources. A model is developed that suggests that the combined richness of the Cape Floral Region on the south coast of Africa, with its high diversity and density of geophyte plants and the rich coastal ecosystems of the associated Agulhas Current, combined to provide a stable set of carbohydrate and protein resources for early modern humans along the southern coast of South Africa during this crucial but environmentally harsh phase in the evolution of modern humans. Humans structured their mobility around the use of coastal resources and geophyte abundance and focused their occupation at the intersection of the geophyte rich Cape flora and coastline. The evidence for human occupation relative to the distance to the coastline over time at PP13B is consistent with this model.
"From a global perspective, there is still little evidence for the use of marine resources before MIS 6. Potential sites include Trinil (Joordens et al., 2009) and Terra Amata (de Lumley, 1966), but anthropogenic accumulation of the marine fauna is not demonstrated . The observed archaeological pattern e discontinuous in space and time, lacking systematic character e contrasts markedly with the Late Pleistocene record (Marean, 2010, 2011; Colonese et al., 2011; Kandel and Conard, 2012; Jerardino, 2010a; Marean, 2014; Will et al., 2015) and fits the expected outcome for groups not fully adapted to coastal niches. Additional support for the idea that coastal adaptations originated after 200 ka could come from sites along coastlines with a steep offshore bathymetric profile and narrow continental shelve, yielding no or only few remains of a limited range of the most easily acquired marine resources along with short-term, ephemeral occupations that date before MIS 5 and escaped erosion by pre-Holocene high stands (see also Fisher et al., 2013). "
[Show abstract][Hide abstract] ABSTRACT: The Middle Stone Age (MSA) of Africa documents the earliest and longest record of marine resource use and coastal settlements by modern humans. Here, we provide a long-term and evolutionary perspective of these behaviors. We propose a definition of " coastal adaptations " rooted in the principles of evolutionary biology as a workable analytical device and review the MSA archaeological record from Africa to characterize the specific nature of coastal adaptations by Homo sapiens. On this basis we evaluate current models addressing the importance of coastal adaptations for human evolution and formulate new hypotheses within the larger framework of evolutionary causality by linking these behaviors directly to reproductive success. While the current archaeological record suggests that modern humans occasionally consumed marine resources during the late Middle Pleistocene, systematic and optimized gathering of a variety of marine food items dates to MIS 5 and 4. Archaeozoological studies show that people exploited marine resources in a methodical manner on the Atlantic, Indian, and Mediterranean coasts of Africa during this time frame. Despite the similarities in coastlines, mobile hunteregatherers also integrated these variable coastal landscapes into their settlement strategies for more than 100 ka, as shown by evidence for stable, repeated and planned occupations. Additionally, elements of complex material culture, such as bone tools and shell beads, occur particularly often in (near-) coastal MSA sites. The specific nature of coastal adaptations by modern humans can thus be characterized by their systematic nature, long duration and verifiable impact on the overall adaptive suite. By combining archaeological data with ethnographic, nutritional and medical studies we propose several evolutionary scenarios for how modern humans could have increased survival and fecundity rates by their specific adaptations to coastal environments. In order to test these hypothetical scenarios for the selective advantages of coastal adaptations for Homo sapiens, we need more data deriving from an expanded spatiotemporal archaeological record, just as much as more formal evolutionary models and research strategies.
Quaternary International 11/2015; DOI:10.1016/j.quaint.2015.10.021 · 2.06 Impact Factor
"Understanding the mechanisms underlying the diversity of early human populations and their dispersals within and out of Africa remains a fundamental challenge of human origins research. A commonly proposed mechanism is environmental change, which may have mediated population distributions and demographics (Scholz et al., 2007; Eriksson et al., 2012; Rito et al., 2013), the opening and closing of biogeographic barriers (Vaks et al., 2007; Cowling et al., 2008; Carto et al., 2009; Compton, 2011; Faith et al., in press), and behavioral adaptations to resource availability (Ambrose and Lorenz, 1990; McCall, 2007; Marean, 2010). Of particular relevance to East Africa, Cowling et al. (2008) propose that the repeated opening and closing of the equatorial East African forest belt throughout the Quaternary, mediated by changes in rainfall and atmospheric CO 2 concentrations, potentially played a key role in the dispersals of humans and fauna. "
"The genomic evidence  means that an abundant dietary source of preformed DHA, as provided in littoral habitats, would actually stimulate the evolution of the brain, and a lack of DHA would be restrictive [6–8,11–14]. What we were doing differently is that we were a very small group of individuals who consistently ate marine and lacustrine food sources . The superabundance of DHA (and Zn, Cu, I, Se, protein etc.), with its irreplaceable role in neural cell signalling, allowed the synaptic evolution of selfawareness and symbolic thinking and behaviour. "
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