Decline of genetic diversity in ancient domestic stallions in Europe.

Present-day domestic horses are immensely diverse in their maternally inherited mitochondrial DNA, yet they show very little variation on their paternally inherited Y chromosome. Although it has recently been shown that Y chromosomal diversity in domestic horses was higher at least until the Iron Age, when and why this diversity disappeared remain controversial questions. We genotyped 16 recently discovered Y chromosomal single-nucleotide polymorphisms in 96 ancient Eurasian stallions spanning the early domestication stages (Copper and Bronze Age) to the Middle Ages. Using this Y chromosomal time series, which covers nearly the entire history of horse domestication, we reveal how Y chromosomal diversity changed over time. Our results also show that the lack of multiple stallion lineages in the extant domestic population is caused by neither a founder effect nor random demographic effects but instead is the result of artificial selection-initially during the Iron Age by nomadic people from the Eurasian steppes and later during the Roman period. Moreover, the modern domestic haplotype probably derived from another, already advantageous, haplotype, most likely after the beginning of the domestication. In line with recent findings indicating that the Przewalski and domestic horse lineages remained connected by gene flow after they diverged about 45,000 years ago, we present evidence for Y chromosomal introgression of Przewalski horses into the gene pool of European domestic horses at least until medieval times

A ritual site with sacrificial wells from the Viking Age at Trelleborg, Denmark

The promontory facing Storebælt with the well-known circular Viking Age military fortress of Trelleborg erected by Harold Bluetooth in AD 980/981 seems to have been an important ceremonial space prior to the erection of the fortress and contemporary with a nearby high status settlement dated to the seventh to the eleventh century. This study presents new cross-disciplinary investigations focusing on three sacrificial well-like structures (47, 50 and 121) from the pre-Christian Viking Age at Trelleborg. Two of the sacrificial wells (47 and 121) included the only skeletal remains of four children hitherto recovered from Danish Viking Age wells. The strontium isotope results of the four children point to local provenance. However, the results of each well seem to pair up in a systematic way pointing to that the children might come from two different key surrounding areas at Trelleborg. Furthermore, the three wells contained animal remains of primarily domestic livestock partly representing consumption waste from either profane or ritual meals deriving from, for example, blót activities. Well 47 produced a young he-goat and well 121 a hindlimb of an above-average-size young horse, a large part of a young cow and a large dog. Altogether intentional offerings deposited while still enfleshed and interpreted to have served as propitiatory sacrifices to honour or appease the gods and to ensure fertility. This research provides new information that enlightens the formation processes underlying accumulation of cultural deposits in features such as ritual wells, in the period prior to Christianity