Thursday, March 02, 2023

Uncovering the voice of toothed whales: A distinct nasal structure helps produce diverse sounds

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Toothed whales like dolphins, orcas, and sperm whales produce their diverse repertoire of sounds through a distinct structure in the nasal passages, but in a way that is strikingly similar to the way terrestrial animals use the larynx or syrinx for vocalization. In a new study, researchers who employed four different techniques to get to the bottom of how these animals make the sounds they do describe this novel sound production system and show how it enables toothed whales to use different vocal registers for echolocation and communication. To date, vocal registers have been confirmed only in humans and crows. Odontocetes (toothed whales) navigate and hunt prey in deep, dark marine environments using echolocation, a strategy that relies on the producing short, rapid and powerful ultrasonic echolocation clicks, which for some species can approach a blistering 200 decibels in volume – just shy of the loudest sounds ever recorded. In addition, toothed whales can produce an acoustically rich collection of grunts, bursts, and whistles used to compose complex vocalizations used for social communication. While its thought that these sounds are created through an airflow-driven sound source called the phonic lips located in the nose, the mechanisms that enable such complex sound production, particularly at depths hundreds of meters below the surface, remain largely unknown. Using a combination of interdisciplinary methods that past studies have lacked – including in vivo imaging and recording in trained whales, novel in vitro laboratory experiments, and techniques used to study sound variation in the human voice – Peter Madsen and colleagues show that odontocete sounds are produced through the nasal passages in a way that is functionally analogous to laryngeal and syringeal sound production in other terrestrial vertebrates, like humans and birds. According to the authors, where laryngeal sound would be hampered by pressure and minimal respiratory air volume, passing air through the nasal passage allows complex sounds to be generated at depths these animals frequent. Madsen et al. also discovered that toothed whales use different vocal registers, namely vocal fry, chest, and falsetto voice, to generate the fundamentally different tones used for echolocation and vocal communication. In a related Perspective, Andrea Ravignani and Christian Herbst discuss the study in greater detail.

**This paper is related to an Annual Meeting Briefing for Science, titled “Uncovering the voice of toothed whales: a distinct nasal structure helps produce diverse sounds,” to be held on March 2nd at 9:00 am US ET. You can access the briefing virtually here if you are registered for the AAAS Annual Meeting. (Please add briefing link to your calendars).

NOTE: If you’d like to attend this and other briefings at the 2023 Annual Meeting and have not yet registered, please do so by March 1st [Register Here. At the Registration Access Code step, please enter PRESS.]**

Study reveals record-high carbon dioxide emissions from boreal fires in 2021

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Boreal fires, which typically account for 10% of global fire carbon dioxide emissions, contributed 23% in 2021, a new study reports. “Boreal forests could be a time bomb of carbon, and the recent increases in wildfire emissions we see make me worry the clock is ticking,” said study author Steven Davis, who will participate in an embargoed briefing on this study this week. Extreme wildfires – which impact the climate through the carbon dioxide they emit – have become more common. Wildfires in tropical forests have received notable attention for their emissions, while fires in boreal forests have attracted much less focus. This is despite the fact boreal forests are the world's largest land biome, and fires in these regions release 10 to 20 times more carbon per unit of area burned than other ecosystems. Monitoring fire emissions in this high-carbon density ecosystems is thus critical for understanding Earth’s temperature and risks to climate mitigation efforts.

Satellite-based approaches to monitoring carbon dioxide emissions from fires can miss emissions from little fires, while bottom-up modeling approaches can miss burning soil fires. Also, carbon dioxide is hard to pinpoint to fires specifically; it can stay in the atmosphere for hundreds of years, meaning background carbon dioxide concentrations are quite high compared to the carbon dioxide emissions released from small fires. To better monitor fire emissions, and in boreal regions in particular, Bo Zheng and colleagues used a new approach to track fire carbon dioxide emissions indirectly. It involved monitoring carbon monoxide, which has a much shorter lifetime in the atmosphere compared to carbon dioxide. The authors used satellite data from MOPITT (Measurements Of Pollution In The Troposphere instrument), the satellite instrument with the longest continuous time series of carbon dioxide measurements to date, to estimate global weekly fire carbon monoxide and carbon dioxide emissions in boreal regions through an atmospheric inversion system approach. This revealed a two-decade trend of expanding summer fires in boreal forests since 2000 and record-high emissions from boreal forest fires in 2021, coinciding with severe heatwave, drought, and high water deficit in boreal regions that year. “Our data analysis implies a link between the extensive boreal fires and climate drivers (especially temperature increase or heatwaves),” they write. They note that boreal ecosystems could become the dominant source regions of intensive fires and fire carbon emissions in the future. They also say the approach they developed to monitor fire emission estimates will be useful in developing a more integrated system capable of monitoring and evaluating global and regional fire carbon budgets, postfire land-use fluxes, and the net impact of fire emissions on atmospheric carbon dioxide.

**This paper is related to an Annual Meeting Briefing for Science, titled “Study reveals record-high carbon dioxide emissions from boreal fires in 2021,” to be held on March 2nd at 10:00 am US ET. You can access the briefing virtually here if you are registered for the AAAS Annual Meeting (Please add briefing link to your calendars).

NOTE: If you’d like to attend this and other briefings at the 2023 Annual Meeting and have not yet registered, please do so by March 1st [Register Here. At the Registration Access Code step, please enter PRESS.]**

Largest-ever genetic analysis of grapevine varieties reveals how glacial cycles shaped grape domestication and the rise of wine

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

In the largest ever genetic analysis of grapevine varieties, including samples from previously undocumented specimens in private collections, researchers provide new insights into how, when, and where wine and table grapevines were domesticated, which has been a longstanding question. “This work represents a major international collaborative effort, challenging to do in any circumstances but especially so given that we conducted it during the COVID-19 pandemic and associated lockdowns,” said author Wei Chen, who will also participate in an embargoed briefing on this study this week.

Even though wine and grapes are very important culturally, when wine and table grapevines were domesticated, and where, has been difficult to confirm. This is largely because there haven’t been sufficiently wide genetic sequencing analyses on grapevine varieties. As a result, there are several standing hypotheses in the literature that remain uncertain. For example, researchers have thought the cultivated wine grapevine (Vitis vinifera) had a single domestication in Western Asia, from which all wine varieties stemmed, and that it happened before the advent of agriculture. They’ve also thought wine grapevines were cultivated before table grape grapevines. Now, a study by Yang Dong and colleagues pushes back on both ideas. Based on vast grapevine genetic data studied, their report shows there were two domestication events for the cultivated wine grapevine in two distinct places – Western Asia and the Caucasus region – separated during the last glacial advance. “Despite being separated by over 1000 [kilometers], the two domestication processes appear to have occurred contemporaneously with a high degree of shared signatures of selection on the same genes,” writes Robin Allaby in a related Perspective. What’s more, they showed that these domestication events took place 11,000 years ago – in line with the advent of farming, and about 4,000 years later than some studies have shown. The genetic data also suggest that wine and table grapes were cultivated at the same time – not the wine grapevine first. The authors also identify some genes involved in domesticating grapes – improving flavor and color and texture – that could help winemakers improve wine today and make varieties more resilient to climate change and other stresses. Among their findings, they uncover more about the genetics underlying white grape color, and the ancient muscat flavor; at least one allele underlying muscat flavor may be detrimental to plant health, they say.

To do this work, Dong and colleagues generated a high-quality chromosome level reference genome of wild grapevine progenitor Vitis sylvestris. They then re-sequenced more than 3,000 individual grapevine plant samples collected from wide geographic locations – including from wild locations and from private collections. “Our collaborators reached out to their connections and looked for old and local varieties,” said Chen. “For instance, a lot of the Armenia [samples] from old vineyards turned out to be undocumented varieties.” The multimedia related to this paper includes videos from several international collaborators reflecting on the study’s process and significance.

**This paper is related to an Annual Meeting Briefing for Science, titled “Largest-ever genetic analysis of grapevine varieties reveals how glacial cycles shaped grape domestication and the rise of wine,” to be held on March 2nd at 11:00 am US ET. You can access the briefing virtually here if you are registered for the AAAS Annual Meeting (Please add briefing link to your calendars).

NOTE: If you’d like to attend this and other briefings at the 2023 Annual Meeting and have not yet registered, please do so by March 1st [Register Here. At the Registration Access Code step, please enter PRESS.]**

Ecological improvement of freshwater ecosystems benefits fish and people

Peer-Reviewed Publication

LEIBNIZ INSTITUTE OF FRESHWATER ECOLOGY AND INLAND FISHERIES

Ecosystem-based habitat enhancement through creation of shallow water zones. 

IMAGE: ECOSYSTEM-BASED HABITAT ENHANCEMENT THROUGH CREATION OF SHALLOW WATER ZONES. PHOTO: THOMAS KLEFOTH view more 

CREDIT: THOMAS KLEFOTH

Biodiversity is declining rapidly. Many conservation actions focus on single species. An alternative approach is to comprehensively improve ecological processes and habitats, thereby supporting entire species communities. This so-called ecosystem-based management is however rarely implemented because it is costly. There is also a lack of evidence that ecosystem-based habitat management is more effective than obvious alternatives, such as releasing animals to enhance stocks.

Important lesson for fish conservation 

A research team based in Berlin, in close cooperation with numerous angling clubs organized in the Angler Association of Lower Saxony, has presented a groundbreaking study. Scientists and practitioners worked together to conduct a set of whole-lake experiments and assess the outcomes of ecosystem-based habitat enhancement versus fish stocking in 20 gravel pit lakes over a period of six years. In some of the lakes, additional shallow water zones were created. In other lakes, coarse wood bundles were added to enhance structural diversity. Other study lakes were stocked with five fish species of interest to fisheries; unmanipulated lakes served as controls. The study was based on a sample of more than 150,000 fish.

The key result: The creation of shallow water zones was the most effective method to enhance fish populations. These zones are ecologically important for many fish species, especially as spawning grounds and nursery areas for young fish. The introduction of coarse wood had only positive effects in selected lakes; fish stocking completely failed. "Restoring central ecological processes and habitats – ecosystem-based management – is likely to have stronger long-term effects for rebuilding fish species and populations than narrow, species-focused conservation actions," explained Johannes Radinger of the IGB, lead author of the study.

From the laboratory to jointly executed whole-lake experiments

Never before have fish communities been studied on such a large-scale set of whole-lake experiments involving numerous angling clubs and other practitioners. "In contrast to studies in the laboratory, field experiments that consider natural ecosystem variation as well as ecological and social interactions allow to gain robust evidence about the effectiveness of management measures," explained Thomas Klefoth, professor at the Hochschule Bremen and co-initiator of the project. "To include multiple gravel pit lakes in the experiments was only possible through close cooperation between research and practice. The transdisciplinary approach contributed to a rethinking of fish stocking and fostered the acceptance of more sustainable, ecosystem-based management alternatives," summarized study leader Robert Arlinghaus, Professor of Integrative Fisheries Management at the HU and the IGB.

Two key messages for freshwater conservation and fisheries management

The study highlights two central messages that are relevant beyond gravel pit lakes to other aquatic ecosystems as well: restoring ecological processes has a more sustainable impact on communities and species than narrow, species-focused conservation actions. Additionally, freshwater biodiversity conservation is most effective when user groups, such as angling clubs, take responsibility and are supported in their efforts by authorities, associations, and science. This approach allows for the reconciliation of conservation and use, as both species and fisheries benefit from ecosystem-based management.

******

About the project:

BAGGERSEE (www.baggersee-forschung.de) is a joint project of the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), the Angler Association of Lower Saxony (AVN), and the Technical University of Berlin (TU), in cooperation with the Hochschule Bremen (HSB). The research and implementation project was funded until the end of 2022 as part of the joint funding initiative "Research for the implementation of the National Biodiversity Strategy" by the Federal Ministry of Education and Research (BMBF) and the Federal Agency for Nature Conservation (BfN) with funds from the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV). The project has been coordinated by Prof. Dr. Robert Arlinghaus, who is affiliated with the IGB and the Humboldt Universität zu Berlin (HU). Further details about the working group can be found at www.ifishman.de.

 

About the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB):

“Research for the future of our freshwaters” is the mission of the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB). IGB is Germany’s largest and one of the leading international centres for freshwater research. It integrates basic and preventive research, and studies freshwater ecosystems and their biotic communities in all their complexity. With more than 350 employees at five locations, the Institute conducts research on how water bodies develop over very long periods of time, how they react to natural and human-caused environmental changes or how new forms of use, restoration or conservation affect rivers, lakes, wetlands and various species. In close collaboration with partners from research, politics, authorities, practice and civil society, IGB also deals with current ecological and societal challenges, such as how adaptation to climate change can succeed, how we protect and conserve aquatic biodiversity and how we use land and water bodies more sustainably. IGB is a member of the Leibniz Association and part of the Forschungsverbund Berlin e.V. www.igb-berlin.de.

European perch (Perca fluviatilis) - one of the study species - is a key predator in temperate lakes. 


Photo: Florian Möllers

Most detailed geological model reveals Earth’s past 100 million years

Sophisticated digital tool can help us understand the past and predict the evolution of the Earth’s surface

Peer-Reviewed Publication

UNIVERSITY OF SYDNEY

Animation of landscape dynamics model over past 100 million years 

VIDEO: ANIMATION OF LANDSCAPE DYNAMICS MODEL OVER PAST 100 MILLION YEARS SHOWING LANDSCAPE EROSION AND SEDIMENT DEPOSITION. view more 

CREDIT: DR TRISTAN SALLES, THE UNIVERSITY OF SYDNEY

Climate, tectonics and time combine to create powerful forces that craft the face of our planet. Add the gradual sculpting of the Earth’s surface by rivers and what to us seems solid as rock is constantly changing.

However, our understanding of this dynamic process has at best been patchy.

Scientists today have published new research revealing a detailed and dynamic model of the Earth’s surface over the past 100 million years.

Working with scientists in France, University of Sydney geoscientists have published this new model in the prestigious journal Science.

For the first time, it provides a high-resolution understanding of how today’s geophysical landscapes were created and how millions of tonnes of sediment have flowed to the oceans.

Lead author Dr Tristan Salles from the University of Sydney School of Geosciences, said: “To predict the future, we must understand the past. But our geological models have only provided a fragmented understanding of how our planet’s recent physical features formed.

“If you look for a continuous model of the interplay between river basins, global-scale erosion and sediment deposition at high resolution for the past 100 million years, it just doesn’t exist.

“So, this is a big advance. It’s not only a tool to help us investigate the past but will help scientists understand and predict the future, as well.”

Using a framework incorporating geodynamics, tectonic and climatic forces with surface processes, the scientific team has presented a new dynamic model of the past 100 million years at high resolution (down to 10 kilometres), broken into frames of a million years.

Second author Dr Laurent Husson from Institut des Sciences de la Terre in Grenoble, France, said: “This unprecedented high-resolution model of Earth’s recent past will equip geoscientists with a more complete and dynamic understanding of the Earth’s surface.

“Critically, it captures the dynamics of sediment transfer from the land to oceans in a way we have not previously been able to.”

Dr Salles said that understanding the flow of terrestrial sediment to marine environments is vital to comprehend present-day ocean chemistry.

“Given that ocean chemistry is changing rapidly due to human-induced climate change, having a more complete picture can assist our understanding of marine environments,” he said.

The model will allow scientists to test different theories as to how the Earth’s surface will respond to changing climate and tectonic forces.

Further, the research provides an improved model to understand how the transportation of Earth sediment regulates the planet’s carbon cycle over millions of years.

“Our findings will provide a dynamic and detailed background for scientists in other fields to prepare and test hypotheses, such as in biochemical cycles or in biological evolution.”

Authors Dr Salles, Dr Claire Mallard and PhD student Beatriz Hadler Boggiani are members of the EarthColab Group and Associate Professor Patrice Rey and Dr Sabin Zahirovic are part of the EarthByte Group. Both groups are in the School of Geosciences at the University of Sydney.

The research was undertaken in collaboration with French geoscientists from CNRS, France, Université Lyon and ENS Paris.

DOWNLOAD animated models of landscape dynamics and photos at this link.

AVAILABLE FOR INTERVIEW

Dr Tristan Salles | School of Geosciences | tristan.salles@sydney.edu.au |
(Speaks English and French)

CAPTION

Lead author Dr Tristan Salles from the School of Geosciences at the University of Sydney.

CREDIT

Stefanie Zingsheim, The University of Sydney

World map animation of landscape evolution over past 100 million years (VIDEO)  https://www.eurekalert.org/multimedia/976138

Animals best to supress personalities for group efficiency

Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

Social animals should limit individuality to conform with the behaviour of the group, a University of Bristol study has found.

Scientists at Bristol’s School of Biological Sciences observed that group safety was improved when animals paid attention to the behaviours of each other.

Their findings, published today in PLoS Computational Biology, reveal that simple social behavioural rules can drive conformity behaviour in groups, eroding consistent behavioural differences shown by individual animals.

Lead author Dr Sean Rands said: “Personality suppression may be a common strategy in group-living animals, and in particular, we should tend to see the behaviours of the most adventurous or shy individuals shifting towards what the majority of the group are doing.”

The team modelled the behaviour of a small group of animals with differing tendencies while performing risky behaviours when travelling away from a safe home site towards a foraging site. They then compared this to their behaviour while completing the same activity in a group.

The group-aware individuals spent longer in the safe space and moved more quickly to the foraging spot, making the mission less dangerous.

Co-author Professor Christos Ioannou, explained: “Groups are usually made up of individuals who are different to each other in the way that they normally behave – these consistent individual differences are what determines the personality of the individual.

“Experimental evidence for this comes from animals like the stickleback fish that we study in our lab. We can measure the personality of individual fish when they are given a food-finding task on their own, and compare it to what happens when they are put in a group of mixed personalities and given the same task.

“When faced with a social task, we find that the fish tend to suppress their own behaviour, and instead conform with what other fish in the group are doing.”

Dr Rands concluded: “We find that if individuals pay attention to other group members, this has an overall impact on the efficiency of the group, and demonstrates that simple social behaviours can result in the suppression of individual personalities.

“This suggests that compromise may lie at the heart of many social behaviours across the animal kingdom.”

 

Paper:

‘Personality variation is eroded by simple social behaviours in collective foragers’ by Sean Rands and Christos Ioannnou in PLoS Computational Biology.

 

“You throw up, then you cough, then you feel better or die”

Children’s drawings during the COVID-19 pandemic - a Swedish study

Peer-Reviewed Publication

UPPSALA UNIVERSITY

Two children fighting Corona 

IMAGE: CHILD, AGED 5: "CORONA. TWO CHILDREN FIGHTING CORONA". A NEW STUDY ABOUT CHILDREN'S DRAWING ABOUT COVID-19 PANDEMIC view more 

CREDIT: SWEDISH ARCHIVE OF CHILDREN’S ART

Detailed images of illness, death and cancelled activities; these were some of the common themes of children’s drawings during the COVID-19 pandemic. A new study from Uppsala University, in which researchers studied 91 drawings made by children aged between 4 and 6, shows that the pandemic affected the children significantly and that they had extensive knowledge about the disease.

It is not every day that children’s drawings become the focus of a scholarly article. In the new study published in the journal Acta Paediatrica, however, the research was entirely based on drawings about the pandemic. The researchers collected all of the drawings produced by children between the ages of 4 and 6 that had been submitted to the Swedish Archive of Children’s Drawings between April 2020 and February 2021.

“It was a very fun study to carry out. I was actually quite uncertain as to whether a medical journal would publish the article, but they did, including the children’s drawings and everything,” explains Anna Sarkadi, Professor of Social Medicine and leader of the study.

Using a method of analysis whereby children’s own explanations of their image were combined with a visual analysis of the drawings, the researchers were able to show that even younger children were strongly affected by the pandemic. They drew detailed images of illness, death and cancelled activities. Fear, worry and missing grandparents were common themes. Some children described the coronavirus as a monster, while others described how to protect yourself. One drawing depicted two children in a fencing battle against a giant virus.

“The drawings were often covered in a lot of snot. On one drawing, a child wrote: ‘You throw up, then you cough, then you feel better or die,’ with extremely clear illustrations,” explains Maria Thell, doctoral student in the CHAP research team and one of the authors behind the study.

The children also had a high level of health literacy related to COVID-19, i.e. knowledge of the virus’s characteristics, how it spread and what symptoms the disease could cause. The project was part of investigations into children’s voices in the public space during the pandemic.

“As a researcher with a background in child and youth science, I would love to develop this method further,” adds Thell.

The team will continue the research at the request of the Public Health Agency of Sweden, which has tasked them with analysing drawings made by 7­­–11-year-olds during or just after the pandemic.

Sarkadi, A, Thell, M, Jirblom, K. Perceptions of the COVID-19 pandemic as demonstrated in drawings of Swedish children aged 4–6 years. Acta Paediatr. 2023; 00: 1– 9. https://doi.org/10.1111/apa.16706

 

Child, aged 6: “Closed for playing” (Lekstängt)

CAPTION

Child, aged 5: “A boy coughed and put his hands over there (on the house) and someone came and touched it, then they got sick. X means that you shouldn't go outside and catch bacteria. The bacteria are underground. Blue faces mean you feel sick.”

CREDIT

Swedish Archive of Children’s Art