A pre-Hispanic canoe or Wampo burial in Northwestern Patagonia, Argentina.

The burial of Individual 3 at the Newen Antug site, a young adult woman, with a pottery grave offering characteristic of the Late Pottery period and dated to 880 years BP, is an indirect burial in a wooden structure. The form and design comprise a wooden wampo or small canoe, or a symbolic representation of one, a metaphor in current and historical Mapuche society for the voyage to the final abode of the dead, located beyond a water body which must be crossed in a boat. This is the first find of a burial in a canoe structure in Argentinian Patagonia, and the most southern example on the whole continent. It is also the earliest record in Argentina of pottery of the Red on White Bichrome tradition used as a grave offering, extending the repertoire of characteristics shared between the two slopes of the Andes mountains during the pottery periods, including ritual as well as material aspects.

Genetic admixture patterns in Argentinian Patagonia.

As in other Latin American populations, Argentinians are the result of the admixture amongst different continental groups, mainly from America and Europe, and to a lesser extent from Sub-Saharan Africa. However, it is known that the admixture processes did not occur homogeneously throughout the country. Therefore, considering the importance for anthropological, medical and forensic researches, this study aimed to investigate the population genetic structure of the Argentinian Patagonia, through the analysis of 46 ancestry informative markers, in 433 individuals from five different localities. Overall, in the Patagonian sample, the average individual ancestry was estimated as 35.8% Native American (95% CI: 32.2-39.4%), 62.1% European (58.5-65.7%) and 2.1% African (1.7-2.4%). Comparing the five localities studied, statistically significant differences were observed for the Native American and European contributions, but not for the African ancestry. The admixture results combined with the genealogical information revealed intra-regional variations that are consistent with the different geographic origin of the participants and their ancestors. As expected, a high European ancestry was observed for donors with four grandparents born in Europe (96.8%) or in the Central region of Argentina (85%). In contrast, the Native American ancestry increased when the four grandparents were born in the North (71%) or in the South (61.9%) regions of the country, or even in Chile (60.5%). In summary, our results showed that differences on continental ancestry contribution have different origins in each region in Patagonia, and even in each locality, highlighting the importance of knowing the origin of the participants and their ancestors for the correct interpretation and contextualization of the genetic information.

Fisher equation for anisotropic diffusion: simulating South American human dispersals.

The Fisher equation is commonly used to model population dynamics. This equation allows describing reaction-diffusion processes, considering both population growth and diffusion mechanism. Some results have been reported about modeling human dispersion, always assuming isotropic diffusion. Nevertheless, it is well-known that dispersion depends not only on the characteristics of the habitats where individuals are but also on the properties of the places where they intend to move, then isotropic approaches cannot adequately reproduce the evolution of the wave of advance of populations. Solutions to a Fisher equation are difficult to obtain for complex geometries, moreover, when anisotropy has to be considered and so few studies have been conducted in this direction. With this scope in mind, we present in this paper a solution for a Fisher equation, introducing anisotropy. We apply a finite difference method using the Crank-Nicholson approximation and analyze the results as a function of the characteristic parameters. Finally, this methodology is applied to model South American human dispersal.