Allometric escape from acoustic constraints is rare for frog calls

Author(s)

Tonini, Joao Filipe Riva ^{[1, 2]} ; Provete, Diogo B. ^{[3, 4]} ; Maciel, Natan M. ^[5] ; Morais, Alessandro Ribeiro ^[6] ; Goutte, Sandra ^{[7, 8]} ; Toledo, Luis Felipe ^[7] ; Pyron, Robert Alexander ^[1]

Affiliation

^[1] George Washington Univ, Dept Biol Sci, Washington, DC 20052 - USA

^[2] Harvard Univ, Dept Organism & Evolutionary Biol, Museum Comparat Zool, Cambridge, MA 02138 - USA

^[3] Gothenburg Global Biodivers Ctr, Gothenburg - Sweden

^[4] Univ Fed Mato Grosso do Sul, Setor Ecol, Inst Biociencias, Campo Grande, MS - Brazil

^[5] Univ Fed Goias, Inst Ciencias Biol, Dept Ecol, Goiania, Go - Brazil

^[6] Inst Fed Goiano, Lab Biol Anim, Rio Verde - Brazil

^[7] Univ Estadual Campinas, Dept Biol Anim, Inst Biol, Lab Hist Nat Anfibios Brasileiros, Campinas - Brazil

^[8] New York Univ Abu Dhabi, Abu Dhabi - U Arab Emirates

• Document type: Journal article
• Source: ECOLOGY AND EVOLUTION; v. 10, n. 8 MAR 2020.
• Web of Science Citations: 0

Abstract

Allometric constraint is a product of natural selection and physical laws, particularly with respect to body size and traits constrained by properties thereof, such as metabolism, longevity, and vocal frequency. Allometric relationships are often conserved across lineages, indicating that physical constraints dictate scaling patterns in deep time, despite substantial genetic and ecological divergence among organisms. In particular, acoustic allometry (sound frequency similar to body size) is conserved across frogs, in defiance of massive variation in both body size and frequency. Here, we ask how many instances of allometric escape have occurred across the frog tree of life using a Bayesian framework that estimates the location, number, and magnitude of shifts in the adaptive landscape of acoustic allometry. Moreover, we test whether ecology in terms of calling site could affect these relationships. We find that calling site has a major influence on acoustic allometry. Despite this, we identify only four major instances of allometric escape, potentially deriving from ecomorphological adaptations to new signal modalities. In these instances of allometric escape, the optima and strength of the scaling relationship are different than expected for most other frog species, representing new adaptive regimes of body size similar to call frequency. Allometric constraints on frog calls are highly conserved and have rarely allowed escape, despite frequent invasions of new adaptive regimes and dramatic ecomorphological divergence. Our results highlight the rare instances in which natural and sexual selection combined can overcome physical constraints on sound production. (AU)

• FAPESP's process: 16/25358-3 - The chytrid fungus: from its origins to its consequences
• Grantee: Luis Felipe de Toledo Ramos Pereira
• Support Opportunities: Research Projects - Thematic Grants