Saturday, April 27, 2013

Human Expansion into the Americas Remains Contentious: Two Contrasting Papers


Dashed lines are approximate boundaries of the extent of settlement based on dated archaeological sites, and solid arrows are hypothesized population movements. A) The initial expansion into southern Siberia from central Asia is relatively uncontroversial. B) Similarly, the expansion from southern Siberia to far-western Beringia by ~30k calBP is uncontroversial. C) Three proposed pre-LGM colonization routes include coastal, terrestrial, and trans-Arctic routes, however, currently there are no archaeological sites beyond western Beringia to support these routes. D) Post-LGM models include the traditional trans-Beringian route, and a coastal route. The trans-Beringian route is the best supported by current archaeological data, and there is no archaeological evidence to suggest the coastal route was a major factor in colonization, albeit complicated by Holocene sea level rise along the Pacific Rim. However, it is entirely feasible that as colonists expanded across the Beringian mainland local groups close to the southern coast may have included aquatic resources in the diet. However, there is no evidence of full maritime cultures anywhere along the Pacific Rim until well into the Holocene.


Authors:

1. Marcus J. Hamilton
2. Briggs Buchanan

Affiliations:

a. Department of Biology, University of New Mexico, Albuquerque, New Mexico, United States of America

b. Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, United States of America

c. Santa Fe Institute, Santa Fe, New Mexico, United States of America

d. Department of Archaeology, Simon Fraser University, Burnaby, Canada

e. Department of Anthropology, University of Missouri, Columbia, Missouri, United States of America

Abstract:

Understanding the dynamics of the human range expansion across northeastern Eurasia during the late Pleistocene is central to establishing empirical temporal constraints on the colonization of the Americas [1]. Opinions vary widely on how and when the Americas were colonized, with advocates supporting either a pre- or post- last glacial maximum (LGM) colonization, via either a land bridge across Beringia, a sea-faring Pacific Rim coastal route, a trans-Arctic route, or a trans-Atlantic oceanic route. Here we analyze a large sample of radiocarbon dates from the northeast Eurasian Upper Paleolithic to identify the origin of this expansion, and estimate the velocity of colonization wave as it moved across northern Eurasia and into the Americas.


The lines represent the closest path for connecting all samples according to the morphological distances between them. Red dots represent samples with Paleoamerican morphology and the brown dot represents the specimens from Zhoukoudian Upper Cave. Blue dots indicate the Late Holocene samples from East Asia, the Americas and Australo-Melanesia.


Authors:

1. Mark Hubbe (a)
2. Walter A. Neves (b)
2. Katerina Harvati (c)

Affiliations:

a. Instituto de Investigaciones Arqueológicas y Museo, Universidad Católica del Norte, San Pedro de Atacama, Chile

b. Laboratório de Estudos Evolutivos Humanos, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil

c. Paleoanthropology Section, Institut für Uhr- und Frühgeschichte und Archaeologie des Mittelalters and Senckenberg Center for Human Evolution and Paleoecology, University of Tübingen, Tübingen, Germany

Abstract:

Discussion surrounding the settlement of the New World has recently gained momentum with advances in molecular biology, archaeology and bioanthropology. Recent evidence from these diverse fields is found to support different colonization scenarios. The currently available genetic evidence suggests a “single migration” model, in which both early and later Native American groups derive from one expansion event into the continent. In contrast, the pronounced anatomical differences between early and late Native American populations have led others to propose more complex scenarios, involving separate colonization events of the New World and a distinct origin for these groups.

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