Final answer:
Environmental conditions in different parts of Africa, such as rainfall patterns and soil fertility, played a significant role in the emergence of agriculture. These conditions led to diverse crop cultivation and the development of different agricultural practices. This explains the differences in crops and the dissemination or independent development of agricultural methods.
Step-by-step explanation:
Environmental conditions in different parts of Africa influenced the emergence of agriculture in various ways. In areas with abundant rainfall and fertile soil, crop cultivation thrived and supported settled human communities. On the other hand, arid regions with limited rainfall and poor soil were more suited for nomadic herding practices. Additionally, the different climate conditions across Africa resulted in varied crop choices and agricultural practices being disseminated or developed independently.