Section 1: Understanding Our Environment Read the passage below and answer the questions that follow.

The agricultural revolution allowed human populations to grow at an unprecedented rate. An area of land can support up to 100 times as many people by farming as it can by hunting and gathering. As populations grew, they began to concentrate in smaller areas. These changes placed increased pressure on local environments, The agricultural revolution also changed the food we eat. The plants we grow and eat today are descended from wild plants. During harvest season, farmers collected seeds from plants that exhibited the qualities they desired. The seeds of plants with large kernels or sweet and nutritious flesh were planted and harvested again. Over the course of many generations, the domesticated plants became very different from their wild ancestors. IDENTIFYING MAIN IDEAS One reading skill is the ability to identify the main idea of a passage. The main idea is the main focus or key idea. Frequently a main idea is accompanied by supporting information that offers detailed facts about main ideas. Read the question and write the answer in the space provided.

1. Why did populations concentrate in smaller areas during the agricultural revolution?​