Acoustic communication, broadly distributed among vertebrates, plays a fundamental role in parental care, mate attraction and various other behaviors. Despite its importance, comparatively less is known about its evolutionary roots. New research from the University of Zurich confirms a common origin of sound production and acoustic communication among choanate vertebrates (lungfishes and tetrapods), dating from the Paleozoic era, at least 407 million years before present.
Choanate vertebrates’ acoustic communication ancestral state reconstruction analysis: tree includes 1,800 choanatian species assigned either with the character presence or absence of acoustic communication; pie charts at ancestral nodes indicate likelihood of each character state; colors in the spectrograms represent sound intensity, with warm colors representing high intensity and cold colors (i.e. blue) representing low intensity or absence of sounds. Image credit: Jorgewich-Cohen et al., doi: 10.1038/s41467-022-33741-8.
“Despite the unquestionable importance of acoustic communication among vertebrates, our knowledge regarding its origin remains sparse,” said study’s first author Gabriel Jorgewich-Cohen, a Ph.D. student with the Paleontological Institute and Museum at the University of Zurich, and his colleagues.
“The current consensus based on available evidence favors a convergent origin of acoustic communication among vertebrates: studies on acoustic sensory abilities show that the morphology in the hearing apparatus and its sensitivity vary considerably among vertebrates.”
“This, in addition to observed differences in vocal tract morphology, suggests that acoustic communication likely evolved multiple times, emerging independently among diverse clades.”
“Phylogenetic analyses used to reconstruct the ancestral state of acoustic communication along the tree nodes, whilst suggestive of multiple origins, are arguably complicated by missing data from key species.”
“An alternative hypothesis is that acoustic communication has a common and ancient evolutionary origin,” they added.
“In support of this, vertebrate hearing epithelia and cerebral promotor circuits that control vocal behaviors are considered to be homologous and operate in the same hindbrain compartment, respectively.”
“Furthermore, in spite of the variety of sound production mechanisms, all choanate lineages have lungs as the physical source of their calling behaviors.”
In their research, the scientists assessed the acoustic communication abilities in 53 species of diverse vertebrate groups, including tuataras, lizards, snakes, salamanders, caecilians, turtles and lungfishes that are key to mapping vocal communication in the vertebrate tree of life.
Using this dataset combined with data of well-known acoustic groups (e.g. mammals, birds and frogs), they tested if the evolutionary origin of acoustic communication is shared among choanate vertebrates.
“This, along with a broad literature-based dataset including 1,800 different species covering the entire spectrum shows that vocal communication is not only widespread in land vertebrates, but also evidence acoustic abilities in several groups previously considered non-vocal,” Jorgewich-Cohen said.
“Many turtles, for example, which were thought to be mute, are in fact showing broad and complex acoustic repertoires.”
“We were able to reconstruct acoustic communication as a shared trait among these animals, which is at least as old as their last common ancestor that lived approximately 407 million years before present,” said study’s senior author Professor Marcelo Sánchez-Villagra, also from the Paleontological Institute and Museum at the University of Zurich.
“Our results now show that acoustic communication did not evolve multiple times in diverse clades, but has a common and ancient evolutionary origin.”
The findings were published on October 25, 2022 in the journal Nature Communications.
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G. Jorgewich-Cohen et al. 2022. Common evolutionary origin of acoustic communication in choanate vertebrates. Nat Commun 13, 6089; doi: 10.1038/s41467-022-33741-8
