What are 3-4 reasons that historians speculate that the agricultural revolution occurred?

Historians speculate that the agricultural revolution occurred because of the following:

1. There are changes in British Farming greatly increased the amount and variety of food produced.

2. Population pressure necessitated agriculture even though it was more work or abundance gave people leisure to experiment with domestication or plating originated as a fertility rite.

3. Wild and unusual variety of native plant may attract the attention of some wild old savage.