AP Human Geography 2016-02-28 Chapter 10 Agriculture I. Key Issue 1: Why Does Development Vary among Countries? 1. Origins of Agriculture a) Hunters and Gatherers ? Before the invention of agriculture, all humans obtained food through hunting for animals, fishing, and gathering plants. ? Hunters and gathers lived in small groups of usually fewer than 50 persons because a larger number would quickly exhaust the available resources within walking distance. The group traveled frequently, establishing new home bases or camps. ? The direction and frequency of migration depended on the movement of game and the seasonal growth of plants at various locations. (1) CONTEMPORARY HUNTING AND GATHERING. ?