Final answer:
The use of irrigation systems dramatically changed life in Eastern Africa by improving agriculture, increasing food production, and supporting larger populations.
Step-by-step explanation:
The innovation that dramatically changed life in Eastern Africa is the use of irrigation systems. An irrigation system is a method used to water crops by artificially supplying them with water. This innovation allowed for more efficient and productive agriculture, as it ensured a consistent water supply to the crops.
With the introduction of irrigation systems, farmers in Eastern Africa could grow crops in areas where rainfall was scarce or unreliable. This led to increased food production, enabling larger populations to be supported and societies to flourish.
Overall, the use of irrigation systems revolutionized agriculture in Eastern Africa and had a significant impact on the region's economy, food security, and social development.