Final answer:
The central cause of the changes described in the excerpt is the shift from hunting and gathering to agriculture.
Step-by-step explanation:
The central cause of the changes described in the excerpt above is the shift from hunting and gathering to agriculture. The adoption of agriculture and the domestication of animals allowed for larger populations, surpluses of food, and labor specialization. This led to the formation of villages, towns, and cities, where people could specialize in different tasks and engage in trade and exchange. The growth of trade further promoted specialization and the development of civilizations.