Final answer:
Our ancestors developed domesticated food plants and began farming to have a more stable and reliable food supply, which allowed for larger populations and the development of settled communities.
Step-by-step explanation:
The main reason our ancestors first developed domesticated food plants and began farming was to have a more stable and reliable food supply. Agriculture allowed people to grow their own crops and cultivate the plants they wanted, which provided them with a consistent source of food. This shift from hunting and gathering to farming allowed for larger populations to be supported and led to the development of settled communities and the specialization of labor.