Acoustic effects accurately predict an extreme case of biological morphology.

The biosonar system of bats utilizes physical baffle shapes around the sites of ultrasound emission for diffraction-based beam forming. Among these shapes, some extreme cases have evolved that include a long noseleaf protrusion (sella) in a species of horseshoe bat. We have evaluated the acoustic cost function associated with sella length with a computational physics approach and found that the extreme length can be predicted accurately from a fiducial point on this function. This suggests that some extreme cases of biological morphology can be explained from their physical function alone.