1. All ages are presented as ka (thousands of calendar years ago). Dates relating to genetic events are in calendar years based on coalescent methods. Dates relating to archaeological events are derived by calibrating radiocarbon ages. Radiocarbon dates younger than 21 000 14 C years ago were calibrated with Calib 5.0.1 (IntCal04 curve); older dates were calibrated by using CalPal Online (CalPal 2007 HULU curve).
2. The Early Settlement of North America: The Clovis Era 2002
3. J. N. Hill, in The Settlement of the American Continents: A Multidisciplinary Approach to Human Biogeography, C. M. Barton, G. A. Clark, D. R. Yesner, G. A. Pearson, Eds. (Univ. of Arizona Press, Tucson, 2004), pp. 39–48.
4. P. Forster, Philos. Trans. R. Soc. London B Biol. Sci.359, 255 (2004).
5. M. Metspalu, T. Kivisild, H.-J. Bandelt, M. Richards, R. Villems, Nucleic Acids Mol. Biol.81, 181 (2006).