Biology is not just about understanding the internal workings of living organisms; it's also about understanding how life interacts with its environment. In "How Life Works," Morris explores the dynamic relationships between organisms and their environments, including the principles of evolution and ecosystems.

Evolution, the process by which species change over time, is a fundamental concept in biology. Morris provides an in-depth exploration of the mechanisms of evolution, including natural selection, genetic drift, and gene flow. Understanding evolution is essential for understanding the diversity of life on Earth, and for addressing many of the biological and environmental challenges that we face today.

Ecosystems, the complex networks of organisms and their environments, are another key area of study in biology. Morris discusses the principles of ecosystem function, including the flow of energy and nutrients through ecosystems, and the interactions between organisms and their environments. These interactions can have profound impacts on the functioning of ecosystems, and on the health and well-being of living organisms.