© Wikimedia Commons, Public Domain. Author: Wilke, 18 July 2004.
The fitness landscape shown here looks like a slice through the free energy landscape shown in Figure 22, and like an extension of the potential sketched in Figure 25 (Unit 4). These different landscapes are illustrations of the same basic idea in physics: A system seeks its lowest energy state and may have to travel over some energy barriers to get there. Sewall Wright's fitness landscape illustrates a similar concept, but in reverse. The height of each peak represents the fitness of a given species to survive in a given set of conditions. Selection pressure drives species up to mountain summits in the fitness landscape. Not surprisingly, physicists working on these problems sometimes choose to draw the fitness landscape upside-down. (Unit: 9)