What are the origins of Vocal Communication?

Vertebrate animals are those that have a backbone or vertebral column. This group includes mammals, birds, reptiles, amphibians, and fish. Of course, among vertebrate animals we include ourselves, human beings.

Until recently, it was considered that only vertebrates choanates (that is, those that are endowed with rear nostrils - "choanas" - and, therefore, breathe through the nose) were capable of emitting sounds to communicate. However, some animals choanates, such as turtles, historically considered "mute" by the scientific community, were left on the sidelines.

A recent study, whose conclusions appeared at the end of 2022, shows that some beings that thought they were incapable of communicating through the emission of sounds, they actually do so usual. Let's see it next, addressing the issue of the origin of vocal communication throughout the evolution of the species.

Origins of vocal communication: a common ancestor?

The accepted theory of the origins of acoustic communication consisted of a parallel evolution in the different clades or groups. However, the recent study, published in the journal

Nature Communications (see bibliography), points to a different hypothesis: that all animals capable of communicating through sounds come from a common ancestor. This animal was the first to present the necessary phonetic skills and lived about 407 million years ago, in the Paleozoic epoch: an animal related to the current lobe-finned fish, belonging to the sarcopterygian family.

This family includes the current lungfish, a type of fish that has both gill-like lung respiration, an adaptation evolved to survive when the water level comes down. Lungfish are key when it comes to understanding the evolution of species, since they represent the link that united aquatic animals with terrestrial ones, in the passage of life from sea to land.

Until the publication of the study's conclusions, lungfish, as well as other species, were considered incapable of making sounds, despite being vertebrate animals. However, the study of Nature Communications sheds new light on this issue.

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Turtles and fish also communicate through sounds.

Phylogenetic analyzes are a type of study that allows analyzing the evolution of a species and its relationship with others. Thanks to phylogenetics, it has been possible to design the evolutionary tree of acoustic communication, which until now did not include species considered incapable of emitting sounds.

The team responsible for the study published in the Nature Communications managed to record the sounds produced by 53 species from different groups of vertebrates considered "mute" until then: lungfish, turtles, caecilians (worm-like amphibians), and tuataras (a Newfoundland reptile). Zealand). These species are vertebrates choanates, that is, they have nostrils, so it seemed likely that they were capable of making sounds like the rest.

Thanks to the recordings it was discovered that, indeed, these animals They are capable of emitting complex and varied sounds to communicate with each other, which differ depending on the situations: attract the couple, defend their territory, and even as a communication system between parents and young. Through the study it was found that the baby turtles emit sounds inside the egg to synchronize hatching and thus be able to avoid the dangers of leaving the nest alone.

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Not only with air sounds are emitted

The emission of sounds is, therefore, crucial for the development and survival of vertebrate animals, and represents an important degree of sophistication in evolution, since it allows them to communicate with their similar.

The importance of communication through sounds to ensure survival is evident in that not only vertebrates with choana communicate in this way, but also other types of fish. According to Gabriel Jorgewich, from the University of Zurich and one of the authors of the article, they would do so through other types of evolutionary characteristics that, by their nature, do not fall within the study.

The use of sounds seems obvious in species that have pulmonary respiration and that inhale oxygen through through the choanae or nostrils, but not so much in species that do not have this type of breathing. However, recent studies show that this type of fish communicates through sounds in a quite complex way.

Aaron Rice and Andrew Bass of Cornell University are two of the scientists studying the phenomenon. Both ensure that, contrary to what we believe, non-lunged fish are capable of communicating in the water. However, how to emit sounds without air intake? Well, through alternative methods, such as teeth grinding and the contraction of the swim bladder muscles, which demonstrates, once again, the importance of acoustic communication for the survival of species.

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The importance of discovery

According to Gabriel Jorgewich Cohen, the study will facilitate the understanding of the evolutionary line of communication vocal, in addition to opening our sights to species that, until now, were not considered capable of emitting sounds.

The new records obtained facilitate the expansion of the design of the evolutionary tree of acoustic communication and allow, in this way, to consolidate the theory of a common ancestor, the first to communicate with their peers through sounds.