Answer:
The pressure of rising population and more workers on the supply of land.
Step-by-step explanation:
Population growth occurs exponentially, so it tends to increaseaccording to the birth rate.
For example, if all individual of a family tree reproduces, the tree tends to increase with each generation. Food production increases arithmetically, so it only increases at a particular point in time. If it is left unchecked, populations can outgrow their available resources.