Data from: Tetrapod vocal evolution reveals faster rates and higher-pitched sounds for mammals

Using the voice to produce sound is a widespread form of communication and
plays an important role across a wide range species as well as contexts.
Variation in the rate and mode of sound production has been extensively
studied across different orders or classes, but understanding vocal signal
evolution ultimately requires comparison across all major lineages
involved. Here we used phylogenetic comparative methods to investigate the
evolution of dominant frequency and its association with body weight
across a balanced set of 873 species of mammals, birds, and frogs. Our
results show that all vocal systems share the same general feature of the
negative allometric relationship between body weight and dominant
frequency, but that mammals clearly deviate compared to frogs and birds.
We found mammals to vocalize at much higher frequencie,s and their signals
evolved 4 to 6-fold faster compared to other tetrapod clades. Although all
three groups strongly rely on vocal communication, our findings show that
only mammals have extensively explored the spectral acoustic space. We
argue that such high vocal diversity of mammals is made possible by their
unique hearing system, and discuss the functional drivers that allowed
their shared ancestors to evolve a richer array of frequencies than other
tetrapods.