Chapter 8: Understanding Populations
This chapter takes a closer look at how populations grow, change, and interact with each other in ecosystems. You’ll learn what determines a population’s size, from birth and death rates to carrying capacity and resource limits. We’ll explore how populations grow (sometimes way too fast), what stops that growth, and the factors—both natural and human—that regulate them. Then we’ll shift to species interactions like competition, predation, parasitism, mutualism, and commensalism. By the end, you’ll see how population dynamics and relationships between species are key to the balance of every ecosystem on Earth.
Chapter 9: The Human Population
This chapter focuses on how the human population has grown and changed over time—and what that means for the planet. You’ll learn how scientists study population size, age structure, and fertility rates to predict trends. We’ll explore the demographic transition model and how countries move through different stages of development. Then, we’ll look at the problems caused by rapid growth, especially in less developed countries, like shortages of fuelwood, unsafe drinking water, and loss of arable land. Finally, we’ll examine how global efforts—especially those focused on education and women’s rights—are helping to slow population growth and plan for the future.
Chapter 10: Biodiversity
This chapter explores the incredible variety of life on Earth—what we call biodiversity—and why it matters more than you might think. We’ll look at biodiversity on three levels: species, genetic, and ecosystem diversity, and how each one helps ecosystems stay stable and resilient. You’ll see how biodiversity benefits us through food, medicine, industry, and just by making the world more beautiful and livable. But biodiversity is under threat, especially from habitat destruction, invasive species, pollution, overharvesting, and climate change—all largely driven by human activity. Finally, we’ll explore what’s being done to protect species and ecosystems, from zoos and breeding programs to habitat conservation plans, international treaties, and grassroots efforts. The big takeaway? Saving biodiversity isn’t just about saving the animals—it’s about saving ourselves.
Mrs. Ederington 