Patterns of modern human diversification: Implications for Amerindian origins

Abstract

The study of modern human origins and the study of the origins of modern human diversity are intimately linked. The evolutionary models employed have implications both for interpreting the significance of morphological variation and evolutionary trends, and in terms of the processes that gave rise to such variation. Although controversial, available evidence is taken to indicate a single, recent origin of modern humans.This paper explores the process of differentiation of modern populations in Asia and argues for morphological discontinuities in the late Pleistocene populations in the region. The intensely studied population history of Eastern Asia suggests that the evolution of the Mongoloid population complex may result from a process of differentiations, expansions, and dispersals, resulting in the development of regional morphological patterns. The relatively late appearance of regional morphological differentiation, especially in Northeast Asia, opens the possibility of the earliest Amerindians not being a typical "Mongoloid" population.A more generalized Mongoloid morphology has been described for both North and South American Paleoindian remains. In this paper, the morphology of a robust, not typically Mongoloid, population in South America is investigated, and its implications for the homogeneity of Amerindians discussed. Since a derived, typically Mongoloid morphology cannot be attributed to the early Amerindian and Fueguian-Patagonian populations, it is argued either that the sinodont dental pattern was acquired in parallel in Asia and the Americas or that at least two migratory waves ancestral to Amerinds took place.Modern humans, Population differentiation, Mongoloid hiso 1995 Wiley-Liss, Inc.

Morphological affinities between Jomon and Ainu: reassessment based on nonmetric cranial traits

“…Recently, morphological affinities between Ainu and Palaeoindians in the New World have been suggested (Brace et al, 2001). The present findings, however, do not necessarily support the Ainu-Palaeoindian connection, because an ancestor-descendant relationship between early and late Holocene American series remains tentative (Steele and Powell, 1992;Lahr, 1995;Owsley, 2001, 2003;Van Vark et al, 2003). However, if we accept the hypothesis that Native Americans are derived from prehistoric Northeast Asians with more generalized craniofacial features (Howells, 1959;Lahr, 1995), the morphological shift of Ainu to the Native Americans throws light on the relationships between prehistoric Northeast Asia and Hokkaido.…”

“…flow, natural selection, or common ancestry (Relethford, 1991(Relethford, , 1996Lahr, 1995). Relethford (1991) goes further to say that the key problem is determining which combination of these factors is responsible for biological relationships Harpending, 1994, 1995;Relethford, 1996).…”

“…In model-free analysis, greater temporal and spatial comparisons are essential for understanding the possible causes of differentiation in local populations (Lahr, 1995(Lahr, , 1996. If the morphological variation observed occurs clinally over space and time, then the cause of this differentiation is not particularly important or it may be unknown.…”

Desarrollo de la Investigación sobre Variación Morfológica de Poblaciones Históricas Sudamericanas Utilizando Rasgos Dentales No Métricos

“…Mientras que genetistas y morfólogos han referido una escasa diversidad en las poblaciones sudamericanas, arqueólogos y lingüistas han argumentado que existen altos niveles de variabilidad cultural entre grupos del continente, esto especialmente relevante en la utilización de rasgos morfológicos dentales (Huf fman). Los aportes de Sutter (2005) refiriendo al menos dos eventos poblacionales ocurridos en Sudamérica (un primero Sundadonteprotagonizado por paleoindios y descendientes del periodo Arcaico-, seguido por un segundo Sinodonte -asociado con el aumento de fertilidad de poblaciones tempranas agricultoras-), representan un claro acercamiento a resolver origen y relaciones filogenéticas de los nativos americanos, "una de las áreas más controversiales de la arqueología y la antropología" (Lahr, 1995). El rasgo premolar Uto-Azteca ha sido propuesto como una variante única entre poblaciones recientes de nativos de Norteamérica y Sudamérica, no observado en el este asiático, distribución geográfica y temporal que ha sugerido diferencias entre poblaciones sudamericanas tempranas y tardías (Huf fman), punto que coincidiría con las aserciones de Sutter (2005).…”

Diversidade craniana humana e suas implicações evolutivas

“…Em oposição à morfologia generalizada pode-se reconhecer a morfologia especializada, correspondente às populações racializadas no nordeste asiático a partir de 40 mil anos atrás. Nativos americanos (ameríndios) em geral e asiáticos (leste da Ásia) modernos são os retentores desse padrão morfológico (Lahr, 1995(Lahr, , 1996. 54 No sentido cladístico, em oposição a derivado (Hennig, 1965 Todos os níveis hierárquicos formados sob o critério morfológico foram analisados seguindo duas abordagens: análise intragrupo e intergrupos.…”