Data from: Adaptive evolution in locomotor performance: how selective pressures and functional relationships produce diversity

Despite the complexity of nature, most comparative studies of phenotypic
evolution consider selective pressures in isolation. When competing
pressures operate on the same system, it is commonly expected that
trade-offs will occur that will limit the evolution of phenotypic
diversity, however, it is possible that interactions amongst selective
pressures may promote diversity instead. We explored the evolution of
locomotor performance in lizards in relation to possible selective
pressures using the Ornstein-Uhlenbeck process. Here, we show that a
combination of selection based on foraging mode and predator escape is
required to explain variation in performance phenotypes. Surprisingly,
habitat use contributed little explanatory power. We find that it is
possible to evolve very different abilities in performance which were
previously thought to be tightly correlated, supporting a growing
literature that explores the many-to-one mapping of morphological design.
While we generally find the expected trade-off between maximal exertion
and speed, this relationship surprisingly disappears when species
experience selection for both performance types. We conclude that
functional integration need not limit adaptive potential, and that an
integrative approach considering multiple major influences on a phenotype
allows a more complete understanding of adaptation and the evolution of
diversity.