Skin and Bones: Functional, Architectural, and Mechanical Differentiation in the Bat Wing
In Bat Biology and Conservation, Smithsonian Institution Press, Washington and London, 1998
Sharon M. Swartz

Engineers and, increasingly, biologists recognize that the functional behavior of
mechanical systems is dictated by the combination of material properties and
structural geometry. What happens to a vertebrate limb when it experiences a load
during locomotion, for example, is a consequence of both the size and shape of the
support elements, composed of bone, cartilage, and ligament, and also of the
particular mechanical properties of the tissues comprising those elements.
Biologists, even those sensitive to the role of material properties in determining
mechanical function, typically proceed immediately to morphology, bypassing
considerations of materials science altogether. This bias probably arises from our
empirical experience with patterned variation observable in vertebrates: Tissue
properties tend to vary little among even distantly related and functionally divergent
groups, whereas anatomical variation is observable at all levels in the taxonomic
hierarchy.