Time and Fitness in Evolutionary Transitions in Individuality

It is striking that the concept of fitness although fundamental in evolutionary theory, still remains ambiguous. I argue here that time, although usually neglected, is an important parameter in regards to the concept of fitness. I will show some of the benefits of taking it seriously using the example of recent debates over evolutionary transitions in individuality. I start from Okasha’s assertion that once an evolutionary transition in individuality is completed an ontologically new level of selection emerges from lower levels of organization. I argue that Okasha’s claim to have identified two ontologically distinct levels of selection is an artifact created by an undeserved comparison between the fitness of the collective level and the fitness of its constituents. Once fitness is assessed over the same period of time at the two levels of organization it becomes clear that only one, unique process of selection is acting upon both levels.