This book explores the Mesolithic period in the central-eastern area of Cantabria (Spain) as a manifestation of sociocultural evolution and change of the societies that lived in the area between the ninth and sixth millennia cal BC, until the introduction of farming. It analyses the subsistence and sociocultural transformations made by hunter-gatherer societies in their adaptation to the environment that emerged from the climate change seen during the Holocene. It also considers the evolutionary processes undergone by social groups based on their experiences and cognitive processes.