RESUMEN
Horses revolutionized human history with fast mobility1. However, the timeline between their domestication and their widespread integration as a means of transport remains contentious2-4. Here we assemble a collection of 475 ancient horse genomes to assess the period when these animals were first reshaped by human agency in Eurasia. We find that reproductive control of the modern domestic lineage emerged around 2200 BCE, through close-kin mating and shortened generation times. Reproductive control emerged following a severe domestication bottleneck starting no earlier than approximately 2700 BCE, and coincided with a sudden expansion across Eurasia that ultimately resulted in the replacement of nearly every local horse lineage. This expansion marked the rise of widespread horse-based mobility in human history, which refutes the commonly held narrative of large horse herds accompanying the massive migration of steppe peoples across Europe around 3000 BCE and earlier3,5. Finally, we detect significantly shortened generation times at Botai around 3500 BCE, a settlement from central Asia associated with corrals and a subsistence economy centred on horses6,7. This supports local horse husbandry before the rise of modern domestic bloodlines.
RESUMEN
An excavation of an Early Iron Age village near Aalborg in Denmark uncovered the jaws and skull fragments from a small mammal that were morphologically identified to the genus Crocidura (white-toothed shrews). Three Crocidura species are known from prehistoric continental Europe but none of them are distributed in Scandinavia, which is why this surprising finding warranted further analyses. The bone was radiocarbon-dated to 2840-2750 calibrated years before present (cal. BP), corresponding to the Late Bronze Age and hence earlier than the Iron Age archeological context in which it was found. Using highly optimized ancient DNA protocols, we extracted DNA from one tooth and shotgun-sequenced the sample to reconstruct a near-complete mitochondrial reference genome (17,317 bp, 32.6× coverage). Phylogenetic analyses determined this specimen as a bicolored shrew (Crocidura leucodon) but with a phylogenetic position basal to the clade of known sequences from this species. The confirmation of Crocidura presence in Denmark by the Late Bronze Age sheds new light on the prehistoric natural history of Scandinavia. We discuss the implications of this finding from both zoo-archeological and ecological perspectives. Furthermore, the mitochondrial genome reconstructed in this study offers a valuable resource for future research exploring the genetic makeup and evolutionary history of Eurasian shrew populations.