Stable population structure in Europe since the Iron Age, despite high mobility.

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000-3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire's mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history.

Klippel-Feil syndrome cases from Slovakia.

OBJECTIVE: This study analyzes two probable cases of Klippel-Feil syndrome (KFS) from the region of modern Slovakia and provides an overview of possible cases reported in 'grey' literature. MATERIALS: Two adult skeletons with probable KFS from Vráble-Velké Lehemby and Radola-Koscelisko. METHODS: Macroscopic analysis was performed using standard osteological methods. RESULTS: The two analyzed skeletons represent probable cases of KFS; one from the Neolithic, and one from the Middle Ages. Additional cases of potential KFS have been indicated within the 'grey' literature. CONCLUSIONS: The study shows that KFS was present in prehistoric eastern Central Europe. The few cases of ancient rare diseases may be a result of past and present bioarcheological research, and many cases are hidden within 'grey' literature. A re-examination of older datasets is vital. SIGNIFICANCE: The described cases from modern Slovakia contributes to a limited list of archaeological cases, thus widening our knowledge about the occurrence of this rare condition throughout Europe in the past. LIMITATIONS: The state of past and present osteo-archaeological research in eastern Central Europe, poor preservation of some remains, and lack of pathognomonic features associated with KFS. SUGGESTIONS FOR FURTHER RESEARCH: Systematic review of older skeletal assemblages and 'grey' literature.