6000–3000 BCE: (Agricultural Exchange Enriching Productivity and Driving Demographic Growth — The Adoption of New Crops and Domestic Animals Further Enrichin…

6000–3000 BCE: (Agricultural Exchange Enriching Productivity and Driving Demographic Growth — The Adoption of New Crops and Domestic Animals Further Enriching the Productivity and Variety of Agricultural Practices in Receiving Regions, the Proportion of Diet Derived from Cultivation and Herding Progressively Growing While the Proportion from Collecting and Hunting Declined, the Increased Productivity Enabling Agricultural Populations to Grow Not Just in Overall Numbers but in the Sizes and Densities of Residential Groupings): The adoption of new crops and domestic animals further enriched the productivity and variety of the agricultural practices of the regions they spread to. In consequence, the proportion of the diet derived from cultivation and herding progressively grew, and the proportion coming from collecting and hunting declined. The increased productivity enabled agricultural populations to continue to grow, and not just to grow in population overall, but often in the sizes and densities of the residential groupings that people lived in. The shift is incremental but irreversible. Each new crop adopted, each new animal integrated into the economy, ratcheted up the carrying capacity of the land and pushed the balance further from foraging toward farming. The hamlets grew into villages. The villages grew denser. And as the residential groupings grew, the social relationships within them grew more complex — more people living in closer proximity requiring more elaborate mechanisms for managing conflict, allocating resources, and organizing collective labor. The age of agricultural exchange was, at its core, an age of concentration — of people, of resources, of social complexity — and it was this concentration that would eventually produce the institutions we call civilization.