Nature Communications


Vocal Communication Originated over 400 Million Years Ago

Acoustic communication is not only widespread in land vertebrates like birds and mammals, but also in reptiles, amphibians and fishes. Many of them are usually considered mute, but in fact show broad and complex acoustic repertoires. According to researchers at the University of Zurich, the evolutionary origin of vocal communication dates back more than 400 million years.

tuatara Vocal Communication Originated over 400 Million Years Ago
Tuatara are found only on New Zealand islands and are considered living fossils. They also communicate acoustically. (Image: Gabriel Jorgewich Cohen)

The use of vocalizations as a resource for communication is common among several groups of vertebrates: singing birds, croacking frogs or barking dogs are some well-known examples. These vocalizations play a fundamental role in parental care, mate attraction and various other behaviors. Despite its importance, little is known about when and at what stage in the evolutionary history of vertebrates this behavior first appeared. Comparative analyses can provide insights into the evolutionary origin of acoustic communication, but they are often plagued by missing information from key groups that have not been broadly studied.

Acoustic abilities are widespread in land vertebrates

An international research team led by the University of Zurich (UZH) has therefore focused on species that have never been accessed before. Their study includes evidence for 53 species of four major clades of land vertebrates – turtles, tuataras, caecilians and lungfishes – in the form of vocal recordings and contextual behavioral information accompanying sound production.

“This, along with a broad literature-based dataset including 1800 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,” says first author Gabriel Jorgewich-Cohen, PhD student at the Paleontological Institute and Museum of UZH.

Many turtles, for example, which were thought to be mute are in fact showing broad and complex acoustic repertoires.

Vocal Communication Originated over 400 Million Years Ago. The researchers were even able to detect acoustic communication in lungfish. (Image: Rafael C.B. Paradero)

Last common ancestor lived about 407 million years ago

To investigate the evolutionary origins of acoustic communication in vertebrates, the researchers combined relevant data on the vocalization abilities of species like lizards, snakes, salamanders, amphibians and dipnoi with phylogenetic trait reconstruction methods. Combined with data of well-known acoustic clades like mammals, birds, and frogs, the researchers were able to map vocal communication in the vertebrate tree of life.

“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,” explains Marcelo Sánchez, who led the study.

Acoustic communication did not evolve multiple times

So far, the scientific consensus favored a convergent origin of acoustic communication among vertebrates since the morphology in hearing apparatus and its sensitivity as well as the vocal tract morphology vary considerably among vertebrates. But according to the UZH researchers, the available evidence for this hypothesis lacks relevant data from key species so far considered non-vocal or neglected.

“Our results now show that acoustic communication did not evolve multiple times in diverse clades, but has a common and ancient evolutionary origin,” concludes Sánchez.


Gabriel Jorgewich-Cohen, Simon William Townsend, Linilson Rodrigues Padovese, et al. Common evolutionary origin of acoustic communication in choanate vertebrates, Nature Communications, 25 October 2022. DOI: 10.1038/s41467-022-33741-8


Press release from the University of Zurich


The fundamental mechanisms underlying the dynamics of brain activity are still largely unknown. Their knowledge could help understand the brain‘s response to pathological conditions, such as brain injury (strokes). Despite the efforts of the scientific community, the neural mechanisms underlying the functional and behavioral recovery of stroke patients are still poorly understood.

The study Recovery of neural dynamics criticality in personalized whole brain models of stroke published in Nature Communications, fruit of an international collaboration between physicists, neurologists, and psychologists, by Rodrigo Rocha, Loren Koçillari, Samir Suweis, Michele De Grazia, Michel Thiebaut De Schotten, Marco Zorzi and Maurizio Corbetta, proposes the theory of brain criticality to explain brain-behaviour relationships in neurological patients.

Interdisciplinary research in neuroscience, inspired by statistical physics, has suggested that healthy brain’s neural dynamics operate at a critical state (i.e., in the vicinity of a critical phase transition between order and disorder) that provides optimal functional capabilities. If criticality is indeed a fundamental property of healthy brains, then neurological dysfunctions shall alter this optimal dynamical configuration. Some studies have reported disrupted criticality during epileptic seizures, slow-wave sleep, anesthesia, and Alzheimer’s disease. However, a crucial test of the hypothesis requires showing alterations of criticality after focal brain injury that cause local alterations of the brain’s structural and functional architecture. Furthermore, these alterations shall improve over time in parallel to recovery. Another prediction is that if criticality is essential for behaviour, then its alteration after focal injury shall relate to behavioural dysfunction and recovery of function. Finally, changes in criticality should also correlate with plasticity mechanisms that underlie recovery.

“The aim of the present work was to address these important questions through an interdisciplinary approach combining neuroimaging, computational neuroscience, statistical physics, and data science methods“, explain Rodrigo Rocha (Department of Physics of the Federal University of Santa Catarina, Florianópolis, Brazil). “We examined how brain lesions change criticality using a novel personalized whole brain modelling approach. Our theoretical framework models individual (i.e., single patient) brain dynamics based on real structural connectivity networks. We studied longitudinally a cohort of first-time stroke and healthy participants with neuropsychological tests, and diffusion weighted imaging (DWI) and functional MRI (fMRI) connectivity measures. We found that patients affected by stroke present at three months decreased levels of neural activity, decreased entropy, and decreased strength of functional connections. All these factors contribute to an overall loss of criticality that improves over time with recovery. We also show that changes in criticality predict the degree of behavioural recovery and critically depend on specific white matter connections. In summary, our work describes an important advance in understanding the alteration of brain dynamics as well as brain-behaviour relationships in neurological patients” says Rodrigo Rocha.

Rodrigo Rocha

“Our results show that personalized whole brain computer models can be used to track and predict stroke recovery at the level of single patients, thereby opening promising paths for novel interventions as computer models will allow to test the efficacy of different strategies to improve function” concludes Maurizio Corbetta (Department of Neuroscience and Padova Neuroscience, University of Padua, and Venetian Institute of Molecular Medicine).

Maurizio Corbetta fisica neuroscienze
Maurizio Corbetta

R.P.R. was funded by Research, Innovation and Dissemination Center for Neuromathematics (FAPESP) and the National Council for Scientific and Technological Development (CNPq), Brasil, to RR; M.T.dS by European Research Council (ERC) H2020 (grant# 818521); M.D.F. and M.Z. the Italian Ministry of Health (Grant# RF-2013-02359306); M.C. by the Italian Ministry of Research Departments of Excellence (2017-2022), CARIPARO foundation (Grant #55403), Italian Ministry of Health (Grant# RF-2018-12366899; RF-2019-12369300), H2020-SC5-2019-2 (Grant # 869505);  H2020-SC5-2019-2 (Grant # 869505).

Info sheet

Who: Department of Physics of the Federal University of Santa Catarina; Laboratory of Neural Computation Istituto Italiano di Tecnologia (Rovereto); Department of Physics and Astronomy of the University of Padua; Brain Connectivity and Behaviour Laboratory of the Sorbonne Universities; Groupe d’imagerie Neurofonctionnelle of the University of Bordeaux; Department of General Psychology of the University of Padua; IRCCS San Camillo Hospital Venice; Department of Neuroscience and Padova Neuroscience Center (PNC), of the University of Padua; and, Veneto Institute of Molecular Medicine (VIMM)

What: Interdisciplinary approach to study the role of brain criticality and brain-behavior relationships in neurological patients published in Nature Communications: Recovery of neural dynamics criticality in personalized whole brain models of stroke.

Teorie della Fisica applicate alle Neuroscienze computer models brains stroke
Computer models of injured brains predict neurological deficits in stroke. Picture by Gerd Altmann

Press release from the University of Padua.

The most extensive system of haze layers ever observed in the solar system have been discovered and characterised on the planet Saturn

High-resolution images obtained by the Cassini spacecraft were used for this purpose by the Planetary Science Group at the University of the Basque Country

Saturn hexagon
High-resolution images of Saturn’s Hexagon obtained by the Cassini spacecraft. Credits: UPV/EHU


A rich variety of meteorological phenomena take place in the extensive hydrogen atmosphere of the planet Saturn, a world about ten times the size of the Earth. They help us to better understand those that operate in a similar way in the Earth’s atmosphere.  Featuring among them due to its uniqueness is the well-known “hexagon”, an amazing wave structure that surrounds the planet’s polar region and whose shape looks as if it had been drawn by a geometrician.

Discovered in 1980 by NASA’s Voyager 1 and 2 spacecraft, it has been observed without interruption since then, despite the planet’s long, strong cycle of seasons. A fast, narrow jet stream flows inside this gigantic planetary wave where winds reach maximum speeds of about 400 km/h. Yet, strangely enough, the wave itself remains almost static; in other words, it barely shifts with respect to the planet’s rotation. All these properties mean that the “hexagon” is a highly attractive phenomenon for meteorologists and planet atmosphere researchers.

Cassini, which was in orbit around the planet between 2004 and 2017, took a vast quantity of images from a whole range of distances from the planet and viewing angles. In June 2015 its main camera obtained very high-resolution images of the planet’s limb which are capable of solving details of between 1 and 2 km; they captured the hazes located above the clouds that shape the hexagonal wave. In addition, it used many colour filters, from ultraviolet to near infrared, thus enabling the composition of these hazes to be studied. To complete this study, images produced by the Hubble Space Telescope taken 15 days later and showing the hexagon not on the limb but seen from above were also used. “The Cassini images have enabled us to discover that, just as if a sandwich had been formed, the hexagon has a multi-layered system of at least seven mists that extend from the summit of its clouds to an altitude of more than 300 km above them,” said Professor Agustín Sánchez-Lavega, who led the study.  “Other cold worlds, such as Saturn’s satellite Titan or the dwarf planet Pluto, also have layers of hazes, but not in such numbers nor as regularly spaced out”.

The vertical extent of each haze layer is between approximately 7 and 18 km thick, and according to the spectral analysis, they contain minute particles with radii of the order of 1 micron. Their chemical composition is exotic for us, because, owing to the low temperatures in Saturn’s atmosphere ranging between 120° C and 180° C below zero, they could comprise hydrocarbon ice crystallites, such as acetylene, propyne, propane, diacetylene or even butane in the case of the highest clouds.

Another aspect studied by the team is the regularity in the vertical distribution of the hazes. The hypothesis put forward is that the hazes are organised by the vertical propagation of gravity waves that produce oscillations in the density and temperature of the atmosphere, a well-known phenomenon on the Earth and on other planets. The researchers raise the possibility that it could be the very dynamics of the hexagon itself and its powerful jet stream that may be responsible for the formation of these gravity waves. On the Earth, too, waves of this type produced by the undulating jet stream travelling at speeds of 100 km/h from West to East in the mid-latitudes have been observed. The phenomenon could be similar on both planets, even though the peculiarities of Saturn mean that it is the only case in the solar system. This is an aspect that remains subject to future research.

Saturn's hexagon
Santiago Pérez-Hoyos, Agustín Sánchez-Lavega, Teresa del Río-Gaztelurrutia and Ricardo Hueso. Credits: UPV/EHU

About the authors at the UPV/EHU  

Agustín Sánchez-Lavega is professor of physics at the UPV/EHU-University of the Basque Country, head of the GCP-Planetary Science Group and holder of the 2016 Euskadi Award for Research.  Teresa del Río-Gaztelurrutia and Ricardo Hueso are tenured lecturers, and Santiago Pérez-Hoyos is a permanent research doctor; they all belong to the GCP.

bibliographic reference


Press release on Saturn’s hexagon from the University of the Basque Country.