Dr Rita Rasteiro

Telephone: +44 (0) 116 223 1235

Email: rr147 at le.ac.uk

Office: Attenborough 704

Genetic data can be used to reconstruct the recent demographic history of human populations. For instance, genetic data can be used to detect, quantify and date past population size changes or admixture events, whereby two or more populations join together to create a new population. But, how much information can genetic data give us about important demographic events of our past? I am interested in applying model-based approaches to questions in Human Past Demography, using either modern and/or ancient DNA. I am particularly interested in understanding how major past demographic events, culture and social practices shaped the genetic diversity and structure of human populations.

The Modelling Migrations project

The past demographic history of the British Isles is an interesting topic of research in human population genetics. Since late Iron Age, these islands suffered the influx of several migration waves from different parts of mainland Europe. Romans, Anglo-Saxons, Vikings and Normans had different influences on the making of Britain. However, the impact of each population on the modern British gene pool is still subject to much debate.

This controversy clearly suggests that more work is needed to improve our understanding of the processes that took place during these migrations on the genetic making of Britain. It is in this context that this work is situated and I propose to use model-based approaches to:

• Study the British Isles Diasporas, using genetic data collected from different databases and published datasets;
• Model the consequences of the several migration waves, using both non-recombining systems (like Y-chromosome and mtDNA), as well as nuclear DNA;
• Ascertain if different patterns of genetic differentiation and diversity are encountered between mtDNA and Y-chromosome data. Infer if these differences are due to different demographic histories for both females and males.
• Identify possible geographical specificities that might help us to understand the impact of different immigration movements on different regions of the British Isles.

I will construct models reflecting the demographic history of the societies that inhabited the British Isles. I will take advantage of the multidisciplinary nature  of the Diasporas Project and use the knowledge in surname analyses, History, Archaeology, Onomastics and Linguistics to build them. I will favour non-equilibrium and spatial admixture (intermarriage) models. Depending of the methods used, several different parameters could be tested, such as different population growth and migration rates, population densities, sex-biased migration, admixture between populations. Different geographic points for the arrival of the migration movements in Britain can also be tested.

Past Research

During my PhD thesis, my research focused specifically on understanding how a major demographic event in Human Prehistory, such as the Neolithic transition, has shaped the genetic diversity and structure of human populations. The Neolithic transition, during which farming-based societies spread and replaced hunter-gatherer societies, took place independently over a few millennia in Europe, Africa, Asia and the Americas. However, the way genetic data are interpreted to understand this process is controversial. The aim of my project was to use admixture models of increasing complexity and genetic data to identify geographical specificities, when possible, which might help us understand the introduction of farming.

Education

• Anthropology (specialization in Biological Anthropology), University of Coimbra, Portugal.
• Master in Human Evolution, University of Coimbra, Portugal.
• PhD in Biology (Population Genetics), under the supervision of Lounès Chikhi. Internal IGC doctoral program (Instituto Gulbenkian de Ciência, Portugal).

Publications

• Rasteiro R and Pereira-Leal JB (2007), Multiple domain insertions and losses in the evolution of the Rab prenylation complex, BMC Evolutionary Biology, 7:140
• Rasteiro R and Chikhi L (2009), Revisiting the peopling of Japan: an admixture approach, Journal of Human Genetics, 54: 349–354. doi:10.1038/jhg.2009.39
• Gamba C, Fernández E, Tirado M, Deguilloux M-F, Pemonge M-H, Utrilla P, Edo M, Molist M, Rasteiro R, Chikhi L and Arroyo-Pardo E (2011). Ancient DNA from an Early Iberian Neolithic population support a pioneer collonization by first farmers. Molecular Ecology 21: 45–56. doi: 10.1111/j.1365-294X.2011.05361.x
• Rasteiro R,  Bouttier P-A, Sousa VC and Chikhi L (2012). Investigating sex-biased migration during the Neolithic transition in Europe, using an explicit spatial simulation framework, Proceedings of the Royal Society B, 279: 2409-2416. doi: 10.1098/rspb.2011.2323
• Rasteiro R and Chikhi L (sub). Female and Male Views on the Neolithic Transition: clues from ancient and modern genetic data.