It has been five years since the publication in 'Antiquity' of a paper introducing the potential of Ancient DNAstudies to an audience of archaeologists. It is now time, after the initial hype and overblown expectations from the media, to sit back and take stock. What has Ancient DNA achieved that is of direct relevance to archaeologists ? It is the aim of this session to present to you, the archaeologist, the results of the last five years' worth of research endeavour (involving the Ancient Biomolecules Initiative and nearly two million pounds of funding),in fairly jargon-free presentations, and place these findings in the context of archaeological theories. With some of the 'Big Questions' in archaeology today, such as the origin(s) of agriculture, the identity of the first farmers in Europe, the transmission of agriculture in the Old World, the domestication of plants and animals, the peopling of the New World, and human evolution itself, Ancient (and modern) DNA is an important new line of evidence which can shed new light on the past and help to distinguish between alternative hypotheses. Do the results agree with orthodox archaeological interpretations, or will the textbooks have to be rewritten ? Or are the scientific interpretations theoretically naive - will the scientists have to rethink the implications of this research ? It's obviously not that simple - most Ancient DNA researchers either work closely with archaeologists or have archaeological training themselves, so the results of their work are closely integrated with other forms of archaeological evidence. If anything Ancient DNA research has helped to refine and define archaeological interpretations of the past.

Introduction: The Impact of Ancient DNA on Archaeology

Hypothesis testing using Ancient DNA

The phylogeographic approach to the genetichistory of populations reconstructs ancestral distributions of lineages for a given stretch of DNA in order to infer past demographic expansions and migrations. This methodology, which has mainly been associated with the analysis of mitochondrial DNA, suffers from the limitation that only extant lineages are analysed. The recovery of ancient DNA from humans, whilst presenting greater difficulties than are usually appreciated due to problems of authentication, has the potential to address this limitation by adding a temporal dimension to the DNA sequence analysis, enabling phylogeographic hypotheses to be tested more directly. Examples concerning the origins of anatomically modern humans and the spread of agriculture into Europe will be discussed.

Genes and Ethnicity

Apart from some notorious psychologists, most human scientists have abandoned the idea that human communities can be classified into distinct 'races'. Modern genetic studies have done much to dispel these scientifically-untenable concepts, albeit in a political climate in which racism has become unacceptable. Although races do not exist, there are still patterns in the distribution of gene frequencies in human communities and many anthropologists continue to equate gene distributions, language and culture. In this paper I will consider some of the theoretical and empirical connotations of the study of human biological and cultural diversity, focusing on case studies in North West Europe and the Pacific.

In conclusion, there are no genetic tests for ethnic identity any more than there are archaeological ones. Nevertheless, it is still possible to use genetic information to inform discussion of the processes of migration, settlement travel or indigenous cultural development. More research is necessary, for example, to relate macro-level studies of gene distributions with micro-level studies of community structure, migration, settlement and intermarriage.

Sex identification of human remains - some implications for gender archaeology

In prehistory, gender archaeology depends on the analysis of representations of humans in various media (rock art, cave paintings, statue stele, pottery) where males and females can be distinguished by the presence of characteristic sexual features; however, Interpreting prehistoric art is fraught with difficulties. Another source of information for gender archaeology is from burials accompanied by grave goods. With burials there are two types of information which can be compared - the biological sex of the burials, and the nature of the grave goods interred with them; these data can be analysed to categorise the objects that typically accompany male and female burials, and anomalies from the norm can be identified. To do this the archaeologist needs a reliable method of identifying the sex of human remains.

Current physical anthropological methods work well with complete remains, but with incomplete skeletal material, cremations or juvenile/infant remains the accuracy of these methods decreases and the element of subjectivity increases.

Much research effort has been put into the development of a simple, PCR-based test to identify the sex of human remains. The extraction of ancient DNA from human remains and the amplification of sequences from the X and Y chromosomes in theory should provide a robust and objective method of identifying the genetic sex of an individual.

Examples where this PCR-based sex identification has been applied will be discussed, along with the as yet only study that has relevance for gender archaeology.

Sorting seeds - using ancient DNA to identify archaeological assemblages of wheat

The domestication of wheat was the key to the evolution of agriculture in the Old World. Accurate identification of the wheats used by early farmers is essential to understand how this process took place. The most abundant source of archaeological assemblages of wheat is in charred remains. Traditionally such remains have been identified on the basis of phenotypic traits in morphology of the grain and chaff. which have been presumed to reflect the underlying genetic makeup. In the absence of chaff, identification becomes less secure, often to the extent that ploidy cannot be assigned with any certainty. The presence of ancient DNAwithin a small proportion of charred grains has facilitated examination of some assemblages directly on a genetic basis, allowing genome identification. Already there have been some surprising enrichments of, and discrepancies with, conventional archaeobotany.

Origins of agriculture - once is not enough

Our understanding of the transition to agriculture would be greatly improved by a better appreciation of the steps involved in establishment of the early Neolithic crop assemblage. Was the domestication of each founder crop a unique event , or did multiple domestications occur in parallel at distinct locations within Southwest

Asia? Current opinion favours a 'single origin' hypothesis for each founder crop with the possible exception of barley. Genetic evidence, based on studies of modern plant populations, has been used to support the notion of single origins, but most of the existing data are inconclusive and much of it can, in fact, be equally well used to support a 'multiple origins' hypothesis. A new form of evidence is needed to break out of the current impasse. That new form of evidence can be provided by ancient DNA.

The origins of domesticated cattle - evidence from DNA studies

The origins and development of domesticated cattle have always fascinated archaeologists, prehistorians and biologists. Recent surveys of DNA variation among extant cattle breeds representing the two major types of cattle (humpless Bos taurus and humped Bos indicus ) have provided fundamental insights into the biological history of cattle. Analysis of DNA sequence variation in the maternally-inherited mitochondrial DNA molecule has revealed that humpedzebu cattle do not share a common domestic origin with humpless taurine cattle and were probably domesticated independently, possibly somewhere on the Indian subcontinent. Nuclear DNAgenetic markers confirm this pattern and also provide a high resolution perspective on genetic exchange and admixture between taurine and zebu populations. In addition, the study of ancient DNA preserved in archaeological cattle remains from Southwest Asia, Africa and Europe promises to shed further light on the genetic origins of domesticated cattle.

DNA analysis and the study of sexual sturcture in extinct human populations

Russia Anthropological and archaeological methods are traditionally used for sex determination of adult skeletons with obvious gender morphologies and where the remains are from a grave with preserved grave goods. However, in the case of children, fragmentary remains, and skeletons with unclear features and with no grave goods, sex determination presents a difficult problem. A molecular-genetic analysis of the sex of human remains from the Early Medieval cemetery (X - XIII centuries AD) at Nefedievo, North Russia, was carried out and the results were compared with archaeological and anthropological data. Teeth (15 skeletons) and bones (9 skeletons) were used as the ancient DNA source. The sequences in DYZ1, DYZ3, DXZ3 loci, and in the first intron of the X-Y homologous gene amelogenin, were amplified. Sex was determined in 87.5% of samples by archaeological criteria, in 95.8% of samples by anthropological methods, and in 79.2% of samples by DNA analysis. PCR allowed the sex of infant’s remains to be identified where the sex could not be determined by anthropological methods and in three remains where sex could not be inferred from archaeological data. We consider that development of molecular technique will make it possible to improve the results of DNA analysis.