First paragraph: Agriculture is the human activity that is acting as a major planetary force in the Anthropo­cene. Although the authors of Breaking Boundaries: The Science of Our Planet dedicated only one chapter to food production (Chapter 11), they contended that four of the nine planetary boundaries within which humanity operates have been overcome by agriculture. The book is organized into three acts or sections. Act I contains four chapters describing keystone events that shaped our planet. It describes a lifeless origin dominated by geophysical processes to the onset of life and the changes brought about by photosynthesis, which spurred aerobic life and multicellular organisms. Earth is a complex system undergoing continuous changes, yet it evolved self-regulating mechanisms to regain homeostasis from disturbances (Chapter 1).