PhD Colloquia 2015 - Guido Barbujani

The last seminar will take place on 29 October at 5 pm in the room B101 of the Polo Ferraris at Povo 2.

This is a mini series of 6 seminars given by top experts in different fields covering almost all the area of the PhD program in Biomolecular Sciences. Each colloquium is a friendly forum where students can learn how to communicate and critically evaluate science. Additionally, it is an opportunity to discuss ongoing research in an informal atmosphere and obtain valuable feedbacks from the experts.
PhD Colloquia bring together young scientists, senior scientists and students in a colloquial setting, encouraging interactions and exchanges of ideas.

• Invited speaker: Guido Barbujani (University of Ferrara)
  Title: "A Southern route of early human dispersal from Africa, and its implications for models of Neandertal hybridization".

Abstract:

Fossil and genetic evidence agree in indicating Africa as the place where Homo sapiens first emerged. However, there is little agreement on whether and to what extent anatomically modern humans admixed with archaic forms
(Neandertals in Europe, Denisovan and perhaps other, unknown form, in Asia). Also, it is unclear whether early modern humans left Africa through a single, major process, dispersing simultaneously over Asia and Europe, or in
two main waves, first through the Arab peninsula into Southern Asia and Oceania, and later through a Northern route crossing the Levant. Accurate genome-based estimates of the divergence times between European and African populations are more recent than those between Australo-Melanesia and Africa, and incompatible with the effects of a single dispersal. This difference cannot possibly be accounted for by the effects of hybridization with the Denisovans in Australo-Melanesia. It seems that the hypothesis of a single major human dispersal from Africa, followed by admixture with Neandertals in the Levant, is hardly compatible with the observed historical and geographical patterns of genome diversity, and that more sophisticated models are needed to account for the patterns of genomic similarity in modern and archaic human populations.