Never-before-seen animal recordings reveal the origins of vocal communication in vertebrates

O acoustic communication it is essential for many vertebrate behaviors, such as attracting a mate or facilitating parental care. The sounds made by mammals, birds and amphibians such as frogs are known, but when did they arise?

Some research has suggested that this type of sound communication evolved independently in different groups, although the possibility of a common origin for this adaptation was far from clear.

Phylogenetic analyzes have provided information on the evolutionary origins of acoustic communication, but to date have not included recordings of key species such as turtles and other reptiles as they were considered incapable of vocal communication.

Now, an international group of researchers presents in the journal Nature Communications new records of 53 species of four groups or ‘clades’ of vertebrates that were found not to be vocalizing: 50 turtlesone tuatara (New Zealand reptile), one cecilia (worm-like amphibian) and a lungfish.

The analysis of these and other audios indicates that acoustic communication in vertebrates with choana any nasal openings laterthat is, they breathe through the nose, may have originated from a common ancestor about 407 million years ago, in the Paleozoic.

“Vertebrates with choanas are represented by tetrapods (amphibians, reptiles, mammals and birds) and by lungfish”, explains the lead author to SINC, Gabriel Jorgewich Cohenbiologist at the University of Zurich (Switzerland), “all other fish do not have choana and, although many of them are able to produce soundsthey do so through an evolutionary innovation that is analogous but different and therefore not comparable from the perspective of our research”.

varied acoustic repertoire

The authors found that all species recorded had a varied acoustic repertoire, which included different audios, from squeaks and clicks up until complex tonal soundsused together to communicate different situations.

“Some use them to attract the partnerothers for protect your territory from counterpartsand there are turtles that make sounds from inside their eggs to synchronize hatchingwhich helps to reduce the individual effort to leave the nest and the risk of being preyed on”, points out Jorgewich Cohen.

These sounds are used to attract a mate, protect territory, care for parents and there are even turtles that produce them from inside their eggs to synchronize hatching.

Gabriel Jorgewich Cohen (University of Zurich)

“There is even a species of turtle (Podocnemis expansa) that uses sounds in the communication between adults and young during feeding behaviors. paternal care”, adds the biologist, “but unfortunately, we cannot yet know the meaning of each of the audios we recorded, although we hope that further research will help answer the questions”.

Anyway, these new recordings served to study when the transmission of information through sounds began in most vertebrates: those that breathe through the nose.

Phylogenetic and acoustic data of 1800 species

To deduce the existence of the common ancestor of 407 million years ago, these 53 records were analyzed and compared with available evolutionary data on the presence or absence of acoustic communication in 1,800 species, belonging to all vertebrate groups except fish. .

“It is generally accepted that this common ancestor was a wolf fin fish (sarcopterygium)even though it is very difficult to specify the species exactly”, comments Jorgewich Cohen, who, together with other authors, highlights the importance of his study to learn more about the origins of communication through sounds that many animals, including animals, use today. humans.