Colonization Models and Initial Genetic Diversity in the Americas

Contradictions and Concordances in American Colonization Models

“…There is little current evidence for human occupation in the high arctic of Canada during the LGM, but a wealth of data on other species confirms that biotically rich refugia existed in the area and could have provided some resource patches for human populations (Shafer et al 2010;Rock ptarmigan, Holder et al 1999;arctic grayling, Stamford and Taylor 2004;collared lemming, Federov and Stenseth 2002). The Northwest Coast refugia are better documented (e.g., Haida Gwaii) and have been instrumental in recent suggestions for an early coastal migration route to the west coast of the Americas (Dixon 1999;Kemp et al 2007;Dillehay et al 2008, Erlandson et al 2011, an archeological perspective supported by several genetic studies (e.g., Fix 2002;Fagundes et al 2008a, b). Loehr et al (2006) also inferred evidence for two interior refugia between the Corilleran and Laurentide ice sheets from mtDNA sequence data from two species of mountain sheep, supporting the lack of continuous glacier coalescence postulated by Barendregt and Duk-Rodkin (2004) and Catto et al (1996).…”

“…Using forward simulation, Fix (2002) argued that the observed geographic pattern of population differentiation in mtDNA haplotypes, as measured by F st , could not be recovered if the colonization was accomplished by a single migrant population after the LGM. However, an earlier colonization, which provides additional time for population differentiation to accrue or a separate coastal migration, was sufficient to account for the observed F st values among contemporary Native American populations (Fix 2005).…”

Cultural Collapse and System Survival Due to Environmental Modification

“…The Fisher model applied on a detailed geography of western Europe [19] fails to account for the known rapid expansion of the neolithic along the Danube-Rhine corridor. This is fixed by higher mobility, modelled as increased diffusion rates along waterways [19,[21][22][23]. Another failing of the Fisher model is that it shows farming arriving in Ukraine from the west, which is inconsistent with the archaeological record.…”

Afinidades biológicas extra-continentais dos paleoíndios tardios de Lagoa Santa e suas implicações para a questão do povoamento do novo mundo: uma abordagem odontométrica

“…Porém, conforme já foi salientado esta hipótese é de difícil constatação já que os eventuais vestígios desta suposta ocupação são inacessíveis aos arqueólogos, pois estariam atualmente submersos (Fladmark, 1979;Dillehay, 1999;Dixon, 2001;Fix, 2002;Kelly, 2003). De qualquer forma, a rota costeira Pacífica parece se enquadrar mais apropriadamente nas evidências geológicas e arqueológicas atuais do que o antigo consenso sobre uma rota pelo corredor livre de gelo (Elias, 2001;Mandrik et al, 2001).…”

“…estava disponível e se isolaram em pequenos grupos adaptando-se a ambientes terrestres (Fladmark, 1979;Dixon, 2001 (Fix, 2002;Surovell, 2003;Kelly, 2003;.…”