Natural mutants in mammalian facial morphology: A review of palate clefting in bats.

Bats (order Chiroptera) exhibit great diversity in the size and shape of their palates. One palate characteristic in particular that diverges from other mammals is the presence of a natural and nonpathological cleft palate in roughly half of the ∼1500 species of bats. Despite being typically detrimental when present in other mammals, bats have repeatedly evolved a midline cleft palate in at least 10 lineages and a bilateral cleft palate at least once and, based on observations presented, possibly more. Additionally, some bats that typically do not have a nonpathological cleft palate have been shown to develop pathological palate clefting. Palate clefting in bats therefore has the potential to offer new perspectives on palate development and morphology. In this review, we discuss some of what is currently known regarding the evolution and development, proposed adaptive significance, biomechanics, and diversity of cleft palate in bats and explore avenues for further research on this important topic.