NEW LIGHT ON OLD BRITONS

Abstracts of papers.

The climate, palaeogeography and early human settlement of Britain over the last million years.                   Nick Ashton

The human settlement of Britain stretches back to almost a million years, but it has been a history of brief incursions governed by the cyclical changes in climate and the changing status of Britain as an island or as a peninsula of the European mainland. This talk will discuss research from the last twenty years that has provided new sites, better dating frameworks, rich environmental information and a growing understanding of the importance of the North Sea Basin and the Channel region for human access to Britain. It will focus on the earliest evidence from Happisburgh where pioneering populations first appeared over 850,000 years ago, to recent results from Barnham with evidence of new technologies and more permanent settlement at 400,000 years ago. The talk will conclude by showing how occupation became increasingly rare due to cold climate or insularity. Larger populations returned as climate warmed at the beginning of the Mesolithic c. 11,000 years ago.

The First Britons: bones and behaviour.                                                                                           Chris Stringer and Silvia Bello
The British fossil human record begins with the possible H. heidelbergensis fossils from Boxgrove at ~500 ka, followed by the Swanscombe cranial bones at ~400 ka, which may represent an early Neanderthal. Later Neanderthal teeth are known from Pontnewydd and La Cotte de St Brelade, at about 230 and 50 ka respectively, while early H. sapiens is represented at sites such as Kent’s Cavern, Paviland and Gough’s from about 40 ka onwards. Investigating the association of hominin remains with specialised bone tools, ritualistic objects and artistic representations allows for a better understanding of the technological and cultural development of these early Britons.

Ancient DNA and the changing structure of the prehistoric British population: from the Mesolithic to the Bronze Age.

For much of the last century, archaeologists have debated the relative roles of migration, admixture and acculturation in determining prehistoric societal change. Recently, advances in DNA sequencing technologies have provided a means to generate genome-wide datasets from archaeological remains dating back over thousands of years, enabling us to test between long-standing proposals of cultural diffusion versus human movement. In this talk we will review two recent studies which use ancient DNA to explore the demography of Britain between the Mesolithic and the early Bronze Age. Both studies identified large-scale population turn-over events, driven by migrations from continental Europe, with little evidence for admixture. Olalde Nature 555, pps 190–196 and Brace Nature Ecology and Evolution in press.                                                                                                        Ian Barnes and Selina Brace

The Genetic structure of the populations of the British Isles.                                                                           Walter Bodmer

DNA based genetic analysis has made it possible to use very large numbers of genetic markers to do fine genetic analysis of closely related populations such as those of different parts of the British Isles. For such studies, however, it is very important to sample populations in a meaningful way. Volunteers who were from rural areas and whose four grandparents were born within 80km of each other area were used for a fine scale genetic analysis of the UK population. Analysing the genetic variation in this sample using techniques that take into account patterns of linkage disequilibrium revealed a striking concordance between genetic clusters and geography. Further analysis of the shared ancestry between these UK clusters and similarly analysed samples from surrounding European countries revealed regional patterns of genetic differentiation that carry clear signals of events in the history of the UK population. Such studies have been extended to Irish populations and their relationships to the UK regional patterns. In this way we can build up a picture of the origins of the populations of the UK and Ireland as they have developed since the end of the last ice age. .    See: Leslie, Stephen, Bruce Winney, Garrett Hellenthal et al. (2015).The fine-scale genetic structure of the British population.  Nature 19 March 2015 volume 519, 209.  Gilbert, Edmund, Seamus O’Reilly, Michael Merrigan et al. (2017). The Irish DNA Atlas: Revealing Fine-Scale Population Structure and History within Ireland. Nature Scientific Reports. nature.com/scientificreports.

Genetics and History: how DNA can be used as a window onto the past.                                                                 Turi King

The use of genetics to look at the past, either collective or personal, has undergone a revolution in recent years. From the technological advances allowing the genetic analysis of ancient remains, through to the boom of commercial genetic genealogy, ancestry and medical testing, Professor Turi King discussed the various ways in which DNA can, and perhaps more importantly, cannot be used to shed light on the past.

The ‘Celts’ in Britain: a romantic fiction?                                                                                                            Barry Cunliffe

Societies need to understand their roots but, in the absence of hard fact, have to use their imaginations. So it was in Britain in the late seventeenth century when antiquarians, learning about Celts from classical texts, named the ancient Britons ‘Celts’ and ‘celtomania’ soon gripped the Atlantic facing regions of Europe. For centuries the Celtic debate was dominated by linguists, archaeologists being prepared to follow the senior discipline, but in the 1960’s traditional narratives were being rejected and students had begun to explore the rapidly growing body of archaeological evidence shorn of preconceptions. Since 2015 these new models are being challenged and refined as ancient DNA evidence becomes available.

The Genomic History of Ireland.                                                                                                                                            Lara Cassidy.

The island of Ireland provides a relatively contained microcosm in which to study the defining demographic events that have shaped European populations. It has acted as the north-western terminus for major continental migrations in the Mesolithic, Neolithic and Chalcolithic periods, while its insular status has afforded it some level of genetic continuity over the past four millennia (Cassidy et al. 2016). Using a dataset of over 100 ancient genomes, encompassing all periods of the island’s prehistory, we chart how these processes of demographic change and continuity led to the formation of the modern Irish genome. Dense sampling across time intervals of known population turnover sheds light on the complex interplay between geography and culture in the assimilation of new peoples to the island. During periods of continuity, we use haplotypic data to dissect subtle patterns of relatedness and difference among more homogeneous populations, giving insight into societal drivers of genetic structure in prehistory.  Proc Natl Acad Sci U S A. 2016;113: 368–373. pmid:26712024                                                                                     .