Visualizations of this quantity can range from simple “Fujiyama” to more complicated “badlands” representations. Stuart Kauffman devised his two-parameter NK model to allow visualizations (10[1])of this quantity to be “tunably rugged” depending on the degree of epistasis. This quantity is plotted on the y-axis of Sewall Wright’s namesake landscapes. According to Kimura’s neutral theory, most genetic variation does not affect this quantity, which is often denoted w. Fisherian runaway explains the presence of ostentatious traits as demonstrating a high level of this quantity. W. D. Hamilton proposed an “inclusive” form of this quantity that increases in kin selection, which helps explain altruistic behavior. For 10 points, name this quantity that measures an organism’s reproductive success. ■END■