Competition between individuals drives the evolution of whole species.
Although the fittest individuals survive the longest and produce the most
offspring, in some circumstances the resulting species may not be optimally
fit. Here, using theoretical analysis and stochastic simulations of a simple
model ecology, we show how the mode of competition can profoundly affect the
fitness of evolved species. When individuals compete directly with one another,
the adaptive dynamics framework provides accurate predictions for the number
and distribution of species, which occupy positions of maximal fitness. By
contrast, if competition is mediated by the consumption of a common resource
then demographic noise leads to the stabilization of species with near minimal
fitness.Comment: 11 pages, 6 figure
