This secondary teaching unit is intended to help students in science and social studies understand some of the forces behind rapid population growth in developing nations and the challenges these countries face. The document includes a student handout that is designed to compare and contrast the demographic transition experienced by developing countries with the changes occurring in Kenya today. It then illustrates the political, economic and environmental impacts of Kenya's rapid population growth. The handout also includes a glossary of terms. The accompanying teaching guide provides five classroom activities that attempt to reinforce the key concepts introduced by the reading. It also discusses how some of our lifestyle decisions can contribute to trends that shape the future. Specific discussion questions precede the teacher's unit and a list of other teaching resources is provided. (TW)