Ancient female from Brześć Kujawski Group carries U5a1c haplogroup. Genome data from 17 individuals spans Middle Neolithic to Early Bronze Age. Migrating Anatolian farmers largely replaced local Mesolithic hunter-gatherers. North-central Poland shows varying hunter-farmer admixture levels. Recurrent admixture between hunters and farmers lasted three millennia. Unadmixed hunter-gatherers coexisted as late as 4300 BCE. Late Neolithic introduces steppe ancestry on smaller scale than central Europe. Local populations show stronger genetic ties to hunter-gatherers than steppe pastoralists. Brześć Kujawski Group advanced Neolithic agriculture with wheat, barley, and livestock. Settlements featured semi-permanent longhouses near water. Pottery displays incised geometric designs. Flint tools include axes and arrowheads. Burials with grave goods indicate social stratification and afterlife beliefs. Group contributed to European Neolithization through farming and architecture.