Game theory, originating in economics, is the science of strategic thinking applicable to various fields, including biology and diplomacy, and is crucial for decision-making in all aspects of business, according to game theorist Kevin Zollman.

In this excerpt from "The Story of CO2," Peter Brennan explains how changes in the Earth's ecosystem led to fire, which in turn led our ancestors to become the "fire apes."

We may be close to finding life beyond Earth. But would we even recognize it if we did? Astrobiologist Betül Kaçar explains what signs NASA is looking for.