Posted on 02/13/2008 10:45:46 AM PST by blam
A Three-Stage Colonization Model for the Peopling of the Americas
Andrew Kitchen1, Michael M. Miyamoto2, Connie J. Mulligan1*
1 Department of Anthropology, University of Florida, Gainesville, Florida, United States of America, 2 Department of Zoology, University of Florida, Gainesville, Florida, United States of America
Abstract
Background
We evaluate the process by which the Americas were originally colonized and propose a three-stage model that integrates current genetic, archaeological, geological, and paleoecological data. Specifically, we analyze mitochondrial and nuclear genetic data by using complementary coalescent models of demographic history and incorporating non-genetic data to enhance the anthropological relevance of the analysis.
Methodology/Findings
Bayesian skyline plots, which provide dynamic representations of population size changes over time, indicate that Amerinds went through two stages of growth ≈40,000 and ≈15,000 years ago separated by a long period of population stability. Isolation-with-migration coalescent analyses, which utilize data from sister populations to estimate a divergence date and founder population sizes, suggest an Amerind population expansion starting ≈15,000 years ago.
Conclusions/Significance
These results support a model for the peopling of the New World in which Amerind ancestors diverged from the Asian gene pool prior to 40,000 years ago and experienced a gradual population expansion as they moved into Beringia. After a long period of little change in population size in greater Beringia, Amerinds rapidly expanded into the Americas ≈15,000 years ago either through an interior ice-free corridor or along the coast. This rapid colonization of the New World was achieved by a founder group with an effective population size of ≈1,0005,400 individuals. Our model presents a detailed scenario for the timing and scale of the initial migration to the Americas, substantially refines the estimate of New World founders, and provides a unified theory for testing with future datasets and analytic methods.
Citation: Kitchen A, Miyamoto MM, Mulligan CJ (2008) A Three-Stage Colonization Model for the Peopling of the Americas. PLoS ONE 3(2): e1596. doi:10.1371/journal.pone.0001596
Academic Editor: Henry Harpending, University of Utah, United States of America
Received: January 8, 2008; Accepted: January 16, 2008; Published: February 13, 2008
Copyright: © 2008 Kitchen et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This study was supported by a grant from the National Science Foundation to CJM (BSR-0518530) and by funds from the Department of Zoology, University of Florida to MMM.
Competing interests: The authors have declared that no competing interests exist.
* To whom correspondence should be addressed. E-mail: mulligan@anthro.ufl.edu
Maybe they made it to here too:
From your LINK. #11
“...But the ultimate proof came when scientists found a debris pile at what may have been a toolmaker’s work station. In the debris pile were distinctive quartz flakes. Some of the flakes could be fitted exactly into the sharpened faces of some of the stone tools, said Waters.”
WOW! GOTCHA!
BRILLIANT POST AND THREAD, going back to read it all now, thanks!
What part of it is invalid, in your opinion? If it's valid, it has obvious value, training new scientists as well as refining models that can be used for medical, botanical, etc., purposes...not to mention serendipitous spinoffs (the ROI is excellent, and is one of the few areas where the federal government has a role). If you believe it's not valid, please share your critique.
Nice find.
Updated Three-Stage Model for the Peopling of the Americas
Plosone.org | September 17, 2008 | CJ Mulligan, A Kitchen, MM Miyamoto
Posted on 09/21/2008 8:18:03 PM PDT by SunkenCiv
http://www.freerepublic.com/focus/chat/2087452/posts
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.