Meeting Abstract
Morphological evolution, especially in the context of adaptive radiation, can be thought of as a process of niche filling wherein species diversify in their ecological habits to exploit the available resources. Interspecific competition is avoided, generally, via phenotypic divergence that facilitates specialization on subsets of the total available resource set. Classic studies of adaptive divergence have focused on morphological characteristics, linking form to function, and function to evolution. While these studies have provided valuable insight into the processes that drive and shape morphological evolution, they do little to explain the processes that may constrain it. This is, in part, because it is difficult to assess the total available niche space that species could theoretically diversify to fill. Without this critical piece, it is difficult to ascertain where within this theoretical space species are competitively excluded, where they are constrained by their ancestry, or where their evolutionary trajectory has led them to the edge of theoretical parameter space. Furthermore, the biomechanical performance landscape conferred by morphological attributes may be a complex assemblage of peaks of high performance amid less advantageous valleys. We used computational fluid dynamics to model lift to drag ratio as a measure of flight performance in a morphological parameter space for bird wings composed of three axes: aspect ratio, camber, and Reynolds number. We then used a large dataset of 3-dimensionally scanned wings from 101 species of birds to assess what proportion of the theoretical performance they have diversified into, and what regions and proportion of that space they occupy.
