The Neolithic and Bronze Age transitions were profound cultural shifts catalyzed in parts of Europe by migrations, first of early farmers from the Near East and then Bronze Age herders from the Pontic Steppe. However, a decades-long, unresolved controversy is whether population change or cultural adoption occurred at the Atlantic edge, within the British Isles. We address this issue by using the first whole genome data from prehistoric Irish individuals. A Neolithic woman (3343–3020 cal BC) from a megalithic burial (10.3× coverage) possessed a genome of predominantly Near Eastern origin. She had some hunter–gatherer ancestry but belonged to a population of large effective size, suggesting a substantial influx of early farmers to the island. Three Bronze Age individuals from Rathlin Island (2026–1534 cal BC), including one high coverage (10.5×) genome, showed substantial Steppe genetic heritage indicating that the European population upheavals of the third millennium manifested all of the way from southern Siberia to the western ocean. This turnover invites the possibility of accompanying introduction of Indo-European, perhaps early Celtic, language. Irish Bronze Age haplotypic similarity is strongest within modern Irish, Scottish, and Welsh populations, and several important genetic variants that today show maximal or very high frequencies in Ireland appear at this horizon. These include those coding for lactase persistence, blue eye color, Y chromosome R1b haplotypes, and the hemochromatosis C282Y allele; to our knowledge, the first detection of a known Mendelian disease variant in prehistory. These findings together suggest the establishment of central attributes of the Irish genome 4,000 y ago.

The nature and distribution of political power in Europe during the Neolithic era remains poorly understood 1 . During this period, many societies began to invest heavily in building monuments, which suggests an increase in social organization. The scale and sophistication of megalithic architecture along the Atlantic seaboard, culminating in the great passage tomb complexes, is particularly impressive 2 . Although co-operative ideology has often been emphasised as a driver of megalith construction1, the human expenditure required to erect the largest monuments has led some researchers to emphasize hierarchy 3 —of which the most extreme case is a small elite marshalling the labour of the masses. Here we present evidence that a social stratum of this type was established during the Neolithic period in Ireland. We sampled 44 whole genomes, among which we identify the adult son of a first-degree incestuous union from remains that were discovered within the most elaborate recess of the Newgrange passage tomb. Socially sanctioned matings of this nature are very rare, and are documented almost exclusively among politico-religious elites 4 —specifically within polygynous and patrilineal royal families that are headed by god-kings 5 , 6 . We identify relatives of this individual within two other major complexes of passage tombs 150 km to the west of Newgrange, as well as dietary differences and fine-scale haplotypic structure (which is unprecedented in resolution for a prehistoric population) between passage tomb samples and the larger dataset, which together imply hierarchy. This elite emerged against a backdrop of rapid maritime colonization that displaced a unique Mesolithic isolate population, although we also detected rare Irish hunter-gatherer introgression within the Neolithic population.

Tuberculosis has plagued humankind since prehistoric times, as is evident from characteristic lesions on human skeletons dating back to the Neolithic period. The disease in man is due predominantly to infection with either Mycobacterium tuberculosis or Mycobacterium bovis, both members of the M. tuberculosis (MTB) complex. A number of studies have shown that when conditions permit, surviving mycobacterial DNA may be amplified from bone by PCR. Such ancient DNA (aDNA) analyses are subject to stringent tests of authenticity and, when feasible, are invariably limited by DNA fragmentation. Using PCRs based on single-nucleotide polymorphic loci and regions of difference (RDs) in the MTB complex, a study was made of five Iron Age individuals with spinal lesions recovered from the cemetery of Aymyrlyg, South Siberia. A sensitive screening PCR for MTB complex mycobacteria was positive in four out of the five cases. Genotyping evidence indicated that all four cases were due to infection with M. bovis rather than M. tuberculosis and the data were consistent with the proposed phylogenetic model of the MTB complex. This is believed to be the first report of M. bovis causing Pott's disease in archaeological human remains. The study shows that genotyping of ancestral strains of MTB complex mycobacteria from contexts of known date provides information which allows the phylogeny of the model to be tested. Moreover, it shows that loss of DNA from RD4, which defines classic M. bovis, had already occurred from the genome over 2000 years before the present.

Scurvy has increasingly been recognized in archaeological populations since the 1980s but this study represents the first examination of the paleopathological findings of scurvy in a known famine population. The Great Famine (1845–1852) was a watershed in Irish history and resulted in the death of one million people and the mass emigration of just as many. It was initiated by a blight which completely wiped out the potato—virtually the only source of food for the poor of Ireland. This led to mass starvation and a widespread occurrence of infectious and metabolic diseases. A recent discovery of 970 human skeletons from mass burials dating to the height of the famine in Kilkenny City (1847–1851) provided an opportunity to study the skeletal manifestations of scurvy—a disease that became widespread at this time due to the sudden lack of Vitamin C which had previously almost exclusively been provided by the potato. A three-scale diagnostic reliance approach has been employed as a statistical aid for diagnosing the disease in the population. A biocultural approach was adopted to enable the findings to be contextualized and the etiology and impact of the disease explored. The results indicate that scurvy indirectly influenced famine-induced mortality. A sex and stature bias is evident among adults in which males and taller individuals displayed statistically significantly higher levels of scorbutic lesions. The findings have also suggested that new bone formation at the foramen rotundum is a diagnostic criterion for the paleopathological identification of scurvy, particularly among juveniles. Am J Phys Anthropol, 148:512–524, 2012. © 2012 Wiley Periodicals, Inc.

Highlights  We examine the diet of two Iron Age populations from the eastern Eurasian steppe.  The proxies used are dental palaeopathology and stable carbon and nitrogen isotopes.  These populations did not solely rely on their herds for subsistence.  Millet and fish formed a substantial component of their diet.  The subsistence strategies of steppe mobile pastoralists are highly complex.