Early Colonisation of the Americas

In our first talk of the Hillary Term, Dr Lorena Beccera Valdiva presented us with her recent research on the emergence of the first humans in the New World. Her work was mainly focused on the analysis and re-analysis of samples from 18 archaeological sites from North and South America by radiocarbon dating technique. She described how they attempted to explore more spatiotemporal development patterns in the Americas by obtaining new radiocarbon dates, building traditional Bayesian age models, and increasing the resolution of sites with older dates refinement. Their project aimed to create an inter-regional prehistoric timeline, resembling the one made by Higham et al. for palaeolithic European sites showing replacement of Neanderthal cultures by those ascribed to Homo Sapiens.

The long-held archaeological assumption was that the Bering Strait was crossed between 13,250 and 12, 800 BP by people of the Clovis complex. This claim was effectively refuted in 1997 with finds from the Monte Verde II site (Southern Chile), where evidence dated to 14, 600 BP was excavated. Dr Valdiva focused her presentation on two sites- Chiquihuite Cave and Anzick 1. Human-made lithic artefacts found at Chiquihuite Cave pushed the date even further and indicated that people were probably present before and during the Last Glacial Maximum (26, 500 – 19, 000 BP). However, evidence from other sites indicates an expansion of the population during the abrupt warming of Greenland Interstadial (14, 700 – 12, 900 BP), and several human cultures overlap with the last appearance dates of 18 faunal genera.

Anzick I site is a Clovis complex burial located in North America (Montana), but surprisingly aDNA of a person from Southern American lineage was found there. Moreover, as the site was dated between 8, 700 and 10, 500 BP, it brings evidence of much sooner genetic branching than was previously expected and opens up a possibility of initial colonisation in several independent waves. Nevertheless, more aDNA evidence from sediments is necessary, combined with chronometric information on extinct faunal remains to firmly approve the outlined hypotheses.

A full article about research conducted by Dr Valdiva can be found here.

-Jakub Senesi

Our next talk about ancient Egyptian underworlds will be held on the 15th of February at 5 pm through Zoom.