Bill Bryson highlights the contrasting approaches of scientists Alfred Russel Wallace and Charles Darwin in their development of the theory of evolution. Wallace's theory emerged from a sudden moment of inspiration, while Darwin dedicated years to meticulous research and contemplation, demonstrating a more gradual and systematic method of discovery.

The disparity in their experiences underscores a sense of injustice within the scientific community. Despite Darwin's extensive efforts and deep thinking, the sudden brilliance of Wallace's insight raises questions about recognition and fairness in scientific achievements.