Fladmark + 40: What Have We Learned about a Potential Pacific Coast Peopling of the Americas?

Abstract

Forty years ago, Knut Fladmark (1979) argued that the Pacific Coast offered a viable alternative to the ice-free corridor model for the initial peopling of the Americas—one of the first to support a “coastal migration theory” that remained marginal for decades. Today, the pre-Clovis occupation at the Monte Verde site is widely accepted, several other pre-Clovis sites are well documented, investigations of terminal Pleistocene subaerial and submerged Pacific Coast landscapes have increased, and multiple lines of evidence are helping decode the nature of early human dispersals into the Americas. Misconceptions remain, however, about the state of knowledge, productivity, and deglaciation chronology of Pleistocene coastlines and possible technological connections around the Pacific Rim. We review current evidence for several significant clusters of early Pacific Coast archaeological sites in North and South America that include sites as old or older than Clovis. We argue that stemmed points, foliate points, and crescents (lunates) found around the Pacific Rim may corroborate genomic studies that support an early Pacific Coast dispersal route into the Americas. Still, much remains to be learned about the Pleistocene colonization of the Americas, and multiple working hypotheses are warranted.

An Oceanographic Perspective on Early Human Migrations to the Americas

“…Several recent papers have addressed archaeological and genetic evidence of early coastal migrations. The timings of the initial migrations into the Americas are supported by evidence of early settlement (e.g., Monte Verde South America by ~14,500 yr BP), after a moderate genetic bottleneck in Beringia about 23,000-19,000 yr BP followed by a rapid population expansion between 18,000 yr BP and 15,000 yr BP (Fagundes et al, 2008(Fagundes et al, , 2018Moreno-Mayar et al, 2018;Braje et al, 2019). This strong population expansion, which ended ~15,000 yr BP, supports pre-Clovis occupation of the New World and suggests rapid settlement of North and South America by humans following a Pacific coastal route.…”

“…Coastal travel to Beringia was also possible, as supported by evidence of "island hopping" in the western North Pacific, consisting of obsidian trade, settlement, and shell middens in the vicinity of Japan as far back as 35,000 yr BP (Erlandson and Braje, 2011;Braje et al, 2019). Early migrations by boat along the North Pacific rim following the route inhabited by similar marine ecosystems are plausible.…”

Maritime Paleoindian technology, subsistence, and ecology at an ~11,700 year old Paleocoastal site on California’s Northern Channel Islands, USA

“…Given that NCI Paleocoastal sites postdate the earliest arrival of people in the Americas by a few millennia, CA-SRI-26 and other North American sites dated to~13,000-11,000 years ago do not confirm the early coastal peopling of the Americas, but they do demonstrate that early maritime adaptations were well established alongside Clovis and Folsom traditions in the American interior [11]. With post-glacial sea level rise posing significant challenges to the preservation and discovery of Late Pleistocene coastal sites, evidence for earlier coastal sites is likely submerged, making the discovery and excavation of sites like CA-SRI-26 vital to our understanding of early coastal peoples in the Americas [1]. Before it is lost to erosion, we hope that further work at the Paleocoastal component at CA-SRI-26 will expand the sample of artifacts and faunal remains recovered, along with our understanding of early Paleocoastal lifeways on California's Channel Islands.…”

“…Although scholars continue to debate the routes and timing of the initial colonization of the Americas, with evidence for human settlement extending to~14,000 or perhaps even 16,000 years ago or more (see [4,6]), a coastal route is now more viable than ever ( [1]; see [45,46] for a debate). Given that NCI Paleocoastal sites postdate the earliest arrival of people in the Americas by a few millennia, CA-SRI-26 and other North American sites dated to~13,000-11,000 years ago do not confirm the early coastal peopling of the Americas, but they do demonstrate that early maritime adaptations were well established alongside Clovis and Folsom traditions in the American interior [11].…”

“…Many archaeologists now believe that the initial peopling of the Americas followed a coastal route around the Pacific Rim from Northeast Asia into the Americas [1]. A growing body of archaeological, geological, and genetic data support the feasibility of such a coastal dispersal, as does extensive evidence for seafaring by anatomically modern humans (AMH) from islands of East Asia and greater Australia between~55,000 and 30,000 years ago [2].…”