The Middle Pleistocene Homo erectus/Homo sapiens transition: New evidence from space curve statistics.
Item
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Title
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The Middle Pleistocene Homo erectus/Homo sapiens transition: New evidence from space curve statistics.
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Identifier
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AAI9315457
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identifier
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9315457
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Creator
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Dean, David.
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Contributor
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Adviser: Eric Delson
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Date
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1993
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Language
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English
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Publisher
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City University of New York.
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Subject
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Anthropology, Physical | Biology, Anatomy | Biology, Biostatistics
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Abstract
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Recent models of the evolution of Homo sapiens, Out of Africa (OA) and Multiregional (MR) continuity, are polarized over the relative roles of replacement and hybridization. Co-opted by the OA model, Brauer's (1982) original "Afro-European sapiens" hypothesis posited hybridization with replacement but gave the upper hand to the role of replacement in the origin of modern humans. Brauer's original model proposed a polyphyletic origin for H. sapiens from developed African and European H. erectus populations. The most recent propositions by the principal OA (Stringer, 1991) and MR (Wolpoff, 1992a) advocates have continued to polarize. Stringer posits an intermediate species, H. neanderthalensis (i.e., "archaic" H. sapiens), between H. erectus and H. sapiens while Wolpoff would synonymize the last two.;This thesis re-assesses the "Traditional" (TR) model of Howells, Howell, and Delson. The TR model proposed here suggests an African, but possibly European, early Middle Pleistocene cladogenetic origin of H. sapiens sensu lato. To test this model three dimensional line tracings of 5 circumvault features were digitized, the glabellar portion of the brow ridge (GBR), the lateral brow ridge, the temporal line, the coronal suture (CS), and the superior nuchal line (SNL), on samples of H. erectus sensu lato (variable numbers for each character), transitional specimens (Bodo, Ndutu, Sale, Broken Hill, Eliye Springs, Saldanha, Petralona, Arago, Swanscombe, Steinheim, and Reilingen), and modern H. sapiens (18). Each transitional line tracing was compared directly to an average line tracing for H. erectus and H. sapiens. A direct morphometric comparison resulted in a chi-square like statistic used to assess affinities of the unknown specimen to the two averages. Space curve averaging and chi square comparisons are discussed in detail. Two of the characters, the GBR and the SNL, indicated that the transitional specimens overwhelmingly sorted with the modern human sample. This result fails to falsify the TR model, but does counter both the MR model and Stringer and Tattersall's current versions of the OA model. The transitional specimens sorted with H. erectus for CS, and there was overlap for the other two characters. Perhaps these three characters are plesiomorphic for all populations examined. Results for the possibly "late archaic" Swanscombe and Reilingen crania support an "accretion" model of steady accumulation of Neandertal apomorphies during the Middle and early Late Pleistocene. This model further suggests that since the origin of H. sapiens clines of archaic features developed in other regional populations, races, with geographical loci of high frequency. Most of these late "archaic" populations are assumed to have either dissipated or been largely swamped by modern features. Anatomically modern populations, now thought to have been emerging from Africa throughout the Late Pleistocene, could have played a major role in forming current "racial" populations and clines.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
