Ancient DNA Reveals the Earliest Evidence of Sheep Flocks During the Late Fourth and Third Millennia BC in Southern Iberia

The Spanish Merino is the most significant sheep breed globally due to its economic and cultural importance in human history. It has also had a substantial influence on the development of other Merino and Merino-derived breeds. Historical sources indicate that crossbreeding to produce finer, higher-quality wool was already taking place in the south of the Iberian Peninsula during the Roman era. This evidence suggests that individuals with a racial pattern very similar to that of the modern Merino may have already existed on the peninsula. The presence of the skeletal remains of these animals at various human settlements dated to the late fourth and third millennia BC could provide insights into the genomics of these ancestral sheep. This study analyses ancient DNA extracted from nine skeletal remains from three archaeological sites in Southern Iberia, dated to the third millennium BC. The samples were sequenced and aligned with the ovine genome. The genetic distances observed among the samples indicate a closer relationship between several animals from the Marinaleda (Seville) and Grañena Baja (Jaén) sites. The study of the slaughter/death age profiles identified at La Minilla (La Rambla, Córdoba) suggests an approach centred on meat exploitation, while the data from Marinaleda (Seville) and Grañena Baja (Jaén) indicate the potential exploitation of secondary resources. A review of the composition of these small ruminant herds could provide insights into the type of secondary resource exploitation that may have been prioritised. Our aim is to investigate the presence of distinct production systems, differentiating between those aimed primarily at meat use and those focused on secondary products. This is the first approach to exploring the genetic evidence for sheep livestock related to its productive use during this period and in this geographical area.