For many years, scientists believed that prehistoric kangaroos in Australia had specialized diets, relying specifically on certain types of plants or vegetation for their survival. This idea suggested that they were unable to adapt to changes in their environment, such as shifts in climate or vegetation patterns. 



When the kangaroos' preferred food sources became scarce, it was assumed that their dietary inflexibility contributed to their extinction. This theory placed dietary specialization as a key reason for the disappearance of some kangaroo species during the Pleistocene epoch.



However, recent research challenges these assumptions, suggesting that these marsupials were more resilient than we initially realized.



<h2 class="wp-block-heading" id="h-diverse-diets-of-prehistoric-kangaroos"> Diverse diets of prehistoric kangaroos</h2>



The study was carried out by experts from <a href="https://www.flinders.edu.au" target="_blank" rel="noreferrer noopener">Flinders University</a> and the Museum and Art Gallery of the Northern Territory (<a href="https://www.magnt.net.au" target="_blank" rel="noreferrer noopener">MAGNT</a>). 



The researchers used cutting-edge techniques to analyze the microscopic patterns of wear on fossilized kangaroo teeth. These patterns revealed the types of food the kangaroos ate.



The results showed that <a href="https://www.earth.com/news/giant-kangaroos-of-the-past-didnt-hop-they-walked-on-all-fours/" target="_blank" rel="noreferrer noopener">prehistoric kangaroos</a> were not limited to specific types of food. Instead, they were generalists, capable of eating a wide variety of plants. This flexibility in diet helped them survive environmental changes over time.



Focusing on fossils from the Victoria Fossil Cave at the Naracoorte Caves World Heritage Area in South Australia, the experts analyzed kangaroo diets across 12 extinct species and compared them with 17 modern species.



The Naracoorte region contains the richest and most diverse fossil deposits of kangaroos from the Pleistocene epoch, making it an ideal location for this research.



<h2 class="wp-block-heading" id="h-flexible-diets-helped-kangaroos-survive">Flexible diets helped kangaroos survive</h2>



“Our study shows that most prehistoric kangaroos at Naracoorte had broad diets. This dietary flexibility likely played a key role in their resilience during <a href="https://www.earth.com/news/protemnodon-kangaroo-fossils-may-explain-their-extinction/" target="_blank" rel="noreferrer noopener">past changes</a> in climate,” explained lead researcher Dr. Sam Arman.



Contrary to previous assumptions, the study revealed that most species were mixed feeders, capable of consuming both shrubs and grasses.



“The distinctive short-faced kangaroo anatomy led to a widespread view that sthenurines were unable to adapt their diets when climate change altered vegetation patterns, leading to their extinction,” said study co-author Professor Gavin Prideaux.



However, the findings suggest that their ability to consume a wide range of foods provided a survival advantage during periods of scarcity.



<h2 class="wp-block-heading" id="h-complex-extinction-dynamics">Complex extinction dynamics </h2>



While the ability to adapt their diets likely helped prehistoric kangaroos survive for a time, it wasn’t the only factor influencing their fate. 



The extinction of these megafaunal kangaroos also involved other challenges, such as their large body size, <a href="https://www.earth.com/news/not-all-kangaroo-ancestors-hopped-as-a-means-of-locomotion/" target="_blank" rel="noreferrer noopener">how they moved</a> (locomotion), and their interactions with early humans, who may have hunted them or altered their habitats. 



To better understand these complex extinction dynamics, the researchers plan to study fossils from other Pleistocene sites. They will focus on the critical period between 60,000 and 40,000 years ago - a time when many large animal species disappeared.



This broader investigation could reveal how different factors worked together to drive kangaroo extinctions.



"Identifying what drove the late Pleistocene megafaunal extinctions on the continents remains one of the most contested topics in historical science," noted the study authors. 



"This is especially so in Australia, which lost 90% of its large species by 40,000 years ago, more than half of them kangaroos."



<h2 class="wp-block-heading" id="h-insights-into-ecosystem-vulnerabilities">Insights into ecosystem vulnerabilities</h2>



The study highlights the ecological roles of prehistoric marsupials, offering valuable insights into the evolution of Australia’s <a href="https://www.earth.com/news/ecosystem-attack-predicting-the-success-of-species-invasions/" target="_blank" rel="noreferrer noopener">ecosystems</a>. 



“Understanding the resilience of ancient species helps contextualize why Australia has been so vulnerable to introduced large mammals like pigs, camels, and deer,” noted Professor Prideaux.



Dr. Arman uses a relatable analogy to describe dietary flexibility: “Most of the time, I don’t need to engage four-wheel drive, but this capability becomes crucial when I do need it.”



<h2 class="wp-block-heading" id="h-extinction-of-australia-s-megafauna">Extinction of Australia’s megafauna </h2>



The research, funded by the <a href="https://www.arc.gov.au" target="_blank" rel="noreferrer noopener">Australian Research Council</a>, reflects a long-standing partnership between Flinders University and MAGNT.



The research also honors the traditional custodians of the Naracoorte region, the Meintangk, Marditjali, and Potaruwutj peoples, and acknowledges the contributions of volunteers and students in collecting and preparing specimens.



The study marks an essential step in understanding the resilience of prehistoric kangaroos, their adaptable diet and the complex interplay of factors that led to the extinction of Australia’s megafauna.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/science.adq4340" target="_blank" rel="noreferrer noopener">Science</a>.



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Prehistoric kangaroos changed their diets to survive climate change

For many years, scientists believed that prehistoric kangaroos in Australia had specialized diets, relying specifically on certain types of plants or vegetation for their survival. This idea suggested that they were unable to adapt to changes in their environment, such as shifts in climate or vegetation patterns. When the kangaroos' preferred food sources became scarce, it was assumed that their dietary inflexibility contributed to their extinction. This theory placed dietary specialization as a key reason for the disappearance of some kangaroo species during the Pleistocene epoch. However,...

Rivers and freshwater lakes are the channels whereby macronutrients, including <a href="https://www.earth.com/news/marine-heatwaves-reduce-the-oceans-ability-to-absorb-carbon/">carbon</a> and nitrogen, make their way from biomass on land to biomass in the sea. Each year, carbon and nitrogen usually enter freshwater systems after being leached out of the fallen leaves of forest trees. Once dissolved in lake water, both of these macronutrients influence ecosystem structure.



But now, a study led by scientists from the <a href="https://www.cam.ac.uk/">University of Cambridge</a> highlights the disruptive influence of outbreaks of leaf-eating caterpillars.&nbsp;&nbsp;



Outbreaks of invasive gypsy moths,&nbsp;Lymantria dispar dispar, and forest tent caterpillar moths,&nbsp;Malacasoma disstria,&nbsp;occur at least every five years in temperate forests. The insects eat their way through so many leaves that the resulting decrease in leaf-fall changes the nutrient cycles between the land and the nearby lakes.



In addition, the caterpillars produce huge quantities of nitrogen-rich droppings (known as frass) that wash into the waterways and act as fertilizer; this changes the water chemistry.



Microbial growth is often limited by the availability of nitrogen, and so adding frass to rivers and lakes may also favor the growth of bacteria and algae in these systems. Increased microbial growth also leads to an increased production of carbon dioxide, as the microbes respire and undergo metabolic reactions.



“These insects are basically little machines that convert carbon-rich leaves into nitrogen-rich poo. The poo drops into lakes instead of the leaves, and this significantly changes the water chemistry – we think it will increase the extent to which lakes are sources of greenhouse gases,” said study senior author Professor Andrew Tanentzap in the University of Cambridge’s Department of Plant Sciences.



The study is believed to be the most extensive research ever conducted on how insect outbreaks impact freshwater carbon and nitrogen cycles. The researchers used 32 years of government data on insect outbreaks in 12 river catchments across Ontario, Canada.&nbsp;



The experts related this data to surveys of lake water chemistry and used satellite images of the forests to track changes in monthly leaf area cover. The results of the study show that, in years in which there are caterpillar outbreaks, the leaf area of forests was reduced by an average of 22 percent, due to the foraging activity of the caterpillars.&nbsp;



Correlated with these insect outbreaks, the nearby lakes contained 112 percent more dissolved nitrogen and 27 percent less dissolved carbon compared to non-outbreak years.&nbsp;



The effects were greatest when lake catchments contained higher proportions of deciduous, broadleaved trees, such as oaks and maples, which are favored by the caterpillars over the leaves of coniferous trees like pines.



In years when there are no outbreaks of leaf-eating insects, carbon and nitrogen usually enter lakes from decaying leaf and needle litter, and this peaks in autumn. In fact, a previous 26-year study of 266 lakes across the northern hemisphere showed that carbon accumulates naturally in these lake waters in a process called "browning." The trend is attributed to a variety of factors including climate change, and recovery from historical acid rain and logging activities.



However, when a caterpillar outbreak occurs, the leaf-fall is reduced to such an extent that carbon accumulation all but ceases for that year, which significantly improves the quality of the lake water.



“Outbreaks of leaf-eating insects can reduce the carbon dissolved in lake water by almost a third when the trees around the lake are mainly deciduous. It’s just amazing that these insects can have such a pronounced effect on water quality,” said study first author Sam Woodman.



The researchers are concerned that as climate change favors the northwards range expansion of insect populations, the risk of outbreaks of leaf-eating caterpillars will increase. This may lead to greater production of CO2 from nitrogen-enriched lakes.&nbsp;



The caterpillar phenomenon is even more worrying since there is an abundance of freshwater lakes further north. Furthermore, climate change is also expected to favor broadleaved deciduous trees around the lakes, which will amplify the effects of the insects.



Outbreaks of defoliator insects are clearly a double-edged sword. In outbreak years the large quantities of frass will favor the growth of greenhouse gas-producing bacteria in lakes at the expense of algae that remove CO2&nbsp;from the atmosphere. On the other hand, the reduction of dissolved carbon in the lakes during outbreak years when there is less leaf-fall has a positive effect on water quality.



“From a water quality perspective they (outbreaks) are a good thing, but from a climate perspective they’re pretty bad – yet they’ve been completely overlooked in climate models," concluded Woodman.



The study is published in the journal&nbsp;<a href="https://www.nature.com/ncomms/">Nature Communications</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Caterpillar outbreaks drive CO2 emissions

Rivers and freshwater lakes are the channels whereby macronutrients, including...

New research led by ecologists at the <a href="https://www.plymouth.ac.uk/">University of Plymouth</a> has found that <a href="https://www.earth.com/news/past-temperatures-are-revealed-by-the-size-of-animals/">temperature</a> increases of about 1.6°C - just below the maximum target established by the Paris Agreement in 2017 - could severely impact algal populations and animal species living in coastal ecosystems.



"Marine rocky intertidal organisms are amongst those most affected by climate change with regional distributional changes observed for many species," wrote the study authors.&nbsp;



"Although often ascribed to increased sea surface temperatures, precise assessment of the local habitat conditions underpinning observed and predicted changes in community assembly is lacking."



The scientists examined how increases in rock surface temperature were affecting the quantity and behavior of animal and plant species currently found in the UK on the shorelines of Cornwall and Devon.&nbsp;



The study was focused on two areas of the region’s north coast (Bude and Croyde), and two on the south coast (Bantham and South Milton Sands), all of which have deep gullies with both north- and south-facing surfaces. The average annual temperatures recorded on the south-facing surfaces were 1.6°C higher than those on the north-facing ones.&nbsp;



These differences in temperature were strongly correlated with species abundance. During the summer of 2018, the researchers found 45 different species on the north-facing sites compared to 30 on the south-facing ones. During the winter, the figures were 42 and 24 respectively, with species such as red seaweed and sea cauliflower being restricted to north-facing surfaces.&nbsp;



Temperature differences were also found to have a significant impact on the breeding patterns of animals in these coastal ecosystems. For instance, five times more dog whelk eggs were found on the north-facing surfaces than on the south-facing ones.



“We have all heard for some time about the importance of limiting average global temperature increases to 1.5°C, and it will undoubtedly be one of the key topics discussed at the forthcoming COP26 conference,” said study senior author Mick Hanley, an associate professor of Plant-Animal Interactions at Plymouth.&nbsp;



“This study shows the impact even that kind of increase could have on important species that contribute to the health and biodiversity of our planet. As such, it does add to overwhelming evidence of the threats posed by human-induced climate change.”



The study is published in the journal <a href="https://www.sciencedirect.com/science/article/abs/pii/S0141113621002385?via%3Dihub">Marine Environmental Research</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Coastal ecosystems are disrupted by small temperature changes

New research led by ecologists at the University of Plymouth...

The sounds of nature, particularly the sounds of bird song, give people a sense of connection to the natural environment and are part of our perception of healthy and functional natural surroundings. Bird song helps us connect to and experience <a href="https://www.earth.com/news/nature-improved-mental-health-of-children-during-lockdown/">nature</a>, a process that is vitally important for mental health and for our sense of well-being.&nbsp;



But with declining bird populations and species diversity across the globe, it is possible that bird song choruses (soundscapes) are also becoming depauperate. In a major new study, a team of international researchers&nbsp;led by scientists from the <a href="https://www.uea.ac.uk/">University of East Anglia</a> (UEA)&nbsp;has developed a method of comparing historical soundscapes over the past 25 years to determine how they have changed.



“The benefits of nature contact are widespread, from improved physical health and psychological well-being to increased likelihood of participating in pro-environmental behavior," said study lead author Dr Simon Butler from UEA’s School of Biological Sciences.



“Bird song plays an important role in defining the quality of nature experiences, but widespread declines in bird populations, and shifts in species’ distributions in response to climate change, mean that the acoustic properties of natural soundscapes are likely to be changing. However, historical sound recordings don’t exist for most places so we needed to develop a new approach to examine this.”&nbsp;



The researchers used annual systematic bird count data from the North American Breeding Bird Survey (NA-BBS) and the Pan-European Common Bird Monitoring Scheme (PECBMS) sites. These data on bird occurrence and abundance were largely collected by citizen scientists over the past 25 years. Given this information, the researchers were then able to use an online database of bird calls (<a href="http://www.xeno-109canto.org">www.xeno-109canto.org</a>) to reconstruct the historical soundscapes from 200,000 locations across the two continents.&nbsp;



The separate, five-minute soundscapes constructed in this way for every site in every year were then analyzed using four indices that characterized song diversity, heterogeneity, evenness and amplitude.



The results showed that natural soundscapes across both continents have become more homogeneous and quieter since the 1990s, suggesting reduced soundscape quality. This finding parallels the significant decline, both in species richness and number of individuals, recorded in NA-BBS surveys, as well as in total number of individuals counted during PECBMS surveys over the past 25 years. “We found a widespread decline in the acoustic diversity and intensity of natural soundscapes, driven by changes in the composition of bird communities," said Dr. Butler.



“These results suggest that the soundtrack of spring is getting quieter and less varied and that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being."



“Given that people predominantly hear, rather than see, birds, reductions in the quality of natural soundscapes are likely to be the mechanism through which the impact of ongoing population declines is most keenly felt by the general public."



Dr. Catriona Morrison, a post-doctoral researcher in UEA’s School of Biological Sciences, conducted the analyses.&nbsp;



“In general, we found that sites that have experienced greater declines in either total abundance and/or species richness also show greater declines in acoustic diversity and intensity," said Dr. Morrison.&nbsp;



“However, initial community structure and how the call and song characteristics of species complement each other, also play important roles in determining how soundscapes change."&nbsp;&nbsp;&nbsp;



“For example, the loss of species such as&nbsp;skylark or nightingale, which sing rich and intricate songs, is likely to have a greater impact on the complexity of the soundscape than the loss of a raucous corvid or gull species. Critically however, this will also depend on how many occurred on the site, and which other species are present.”&nbsp;



“Unfortunately, we are living through a global environmental crisis, and we now know that the diminishing connection between people and nature may be contributing to this."&nbsp;&nbsp;&nbsp;



“As we collectively become less aware of our natural surroundings, we also start to notice or care less about their deterioration. Studies like ours aim to heighten awareness of these losses in a tangible, relatable way and demonstrate their potential impact on human wellbeing.”&nbsp;



The study is published in the journal <a href="https://www.nature.com/ncomms/">Nature Communications</a>.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

The bird songs of spring are getting quieter

The sounds of nature, particularly the sounds of bird song,...

New research led by the <a href="https://www.technion.ac.il/en/home-2/">Israel Institute of Technology</a> has found that barn owls (Tyto alba) build mental maps of their surroundings while flying. The experts report that specific neurons in the hippocampus – the part of the <a href="https://www.earth.com/news/dogs-and-infants-recognize-words-using-similar-brain-regions/">brain</a> responsible for spatial orientation - become activated when the owls pass through certain locations.



Place cells – clusters of neurons that fire at a high rate when an animal visits a particular location - are known to exist in the human brain, and they were recently discovered in the brains of other mammals too, including various species of rodents and bats. However, this is the first time that evidence of place cells have been discovered in birds during flight.&nbsp;



The researchers implanted wireless neural recording devices in the brains of six barn owls and analyzed their brain activity as they flew back and forth between two perches.&nbsp;



The experts found that certain neurons from the owls’ hippocampus fired more strongly at specific points along their flight path. This neuronal activity did not appear to be affected by the lighting conditions in the testing room or the movements of the experimenters.



“In the barn owl — a central place forager that strongly relies on memory to navigate&nbsp;to strategic standing posts and to its roost at night — we found robust place cell representation,” reported the study authors in a preprint version of their article.



According to Kate Jeffrey, a neuroscientist at University College London, the Israeli team’s evidence for the presence of place cells in barn owls was “fairly convincing.” This discovery is “consistent with emerging findings from other labs that many of the phenomena we have been studying in mammals have counterparts in non-mammals, suggesting an ancient evolutionary origin, more than 300 million years.”&nbsp;



“Across species, the occurrence of place-cells is correlated with strong reliance on spatial memory. We speculate that the owl’s ability to hunt and navigate in nearly-complete darkness is made possible, in part, by an exceptional hippocampal-based spatial memory,” the study authors concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Barn owls construct mental maps during flight

New research led by the Israel Institute of Technology has...

Experts at the <a href="https://www.bigelow.org/">Bigelow Laboratory for Ocean Sciences</a> are hopeful that a unique case of <a href="https://www.earth.com/news/global-warming-harms-organisms-living-in-symbiosis/">symbiosis</a> between salamanders and algae will lead to a breakthrough in medical research. The team, which includes biologists and natural product chemists at the University of North Carolina Wilmington and Gettysburg College, just received a grant to finance three years of research.



"We are hopeful that the connections between salamanders and algae could lead to exciting and unforeseen discoveries in medicine. And we are grateful to the William Procter Fund for the chance to explore this unique relationship," said lead researcher John Burns.



Interestingly, algae grows on salamander eggs shortly after they’re laid. The algae colonizes and even enters the tissues of the developing salamanders. The amphibians aren’t harmed by the plant but gain oxygen. In return, the algae gets a substrate to grow on.&nbsp;



“These two organisms are coexisting and benefiting one another," explained Burns. "We are trying to find out how the salamander and algae interact, and whether the molecules they are using can be used to regulate immunity in humans.”



Chemical interactions in nature are a traditional source of drugs but as the easily accessed sources for these drugs have been tapped, drug development slowed towards the end of the twentieth century. Symbiotic relationships are still relatively untapped for their possibilities in drug development.



“When we look to the natural world for drugs, we are usually looking at antagonisms. We're looking for the kind of thing that stops bacteria from growing in order to find something we might be able to use in our own bodies," said Burns.&nbsp;



"Studying these organisms in a symbiotic relationship is completely new, and that's why we think it's an interesting place to look for new types of drugs."



Salamanders can regenerate their tails and limbs, and the experts will investigate the potential role of algae in promoting this regeneration. The findings could ultimately lead to the development of treatments to repair human tissue.



"We are taking this natural interaction and trying to figure out how it works to better understand how the two organisms communicate and benefit. This relationship has existed for a long time, so there may be a lot of chemical nuance and possibility to be discovered.”



The study is supported by the <a href="https://umaine.edu/news/blog/2021/08/26/william-procter-scientific-innovation-fund-50000-grant-to-launch-umaine-blue-economy-program/">William Procter Scientific Innovation Fund</a>.



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By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Salamanders have an intriguing partnership with algae

Experts at the Bigelow Laboratory for Ocean Sciences are hopeful...

Have you ever heard of a dog barking softly? Unless a dog’s vocal cords are damaged or in ill health, it can really only bark loudly. Humans, however, are able to modulate the tone of their <a href="https://www.earth.com/news/mountain-lions-afraid-humans/">voices</a> and speak loudly or softly at will. Surprisingly, a new study indicates that baby seals may be able to do the same.



In this study, eight harbor seal pups between one and three weeks of age were exposed to noises of different intensities. The pups were held in a rehabilitation center (the Dutch Sealcentre Pieterburen) prior to being released back into the wild.&nbsp;



To investigate whether the baby seals could adapt their voices to noises in the environment, the researchers recorded noises from the nearby Wadden Sea and then played these noises back to the pups for several days.&nbsp;



The recordings were played back at three different levels of loudness (from no sound to 65 decibels). The pitch of the sea sounds was kept at the same level as the regular pitch of the seals pups’ calls. The researchers also recorded the spontaneous calls by the baby seals.&nbsp;



Analysis of the recordings showed that when the seal pups heard louder sea noises, they lowered their tone of voice. The pups also kept a steadier pitch with the more intense noise levels.&nbsp;



One seal behaved in the opposite manner and produced louder calls when the noise got louder. This is known as Lombard effect and it is typical in human speech when people raise their voices against a background noise, in order to be understood better. The pups did not produce more or longer calls when they heard different levels of sea noise.



Overall, however, it was clear that young seals adapted to the noises in their environment by lowering the tone of their voice - an ability they seem to share with humans and bats. Other animals in similar experiments only raise their voice (in other words, make louder calls) in response to louder noise.



“Seal pups have a more advanced control over their vocalizations than assumed up until now,” noted study senior investigator Andrea Ravignani, scientist at the <a href="https://www.mpi.nl/">Max Planck Institute for Psycholinguistics</a>.



“This control seems to be already present at only few weeks of age. This is astonishing, as few other mammals seem capable of that.&nbsp;To date, humans seem to be the only mammals with direct neural connections between the cortex (the outer layer of the brain) and the larynx (what we use to produce tone of voice)."



“These results show that seals may be the most promising species to find these direct connections, and unravel the mystery of speech.”



“By looking at one of the few other mammals that may be capable of learning sounds, we can better understand how we, humans, acquire speech, and ultimately why we are such chatty animals."



The results of the study were published today in the <a href="https://royalsocietypublishing.org/journal/rstb">Philosophical Transactions of the Royal Society B; Biological Sciences</a>.



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Baby seals "talk" more softly when there is background noise

Have you ever heard of a dog barking softly? Unless...

A study led by <a href="https://www.syracuse.edu/">Syracuse University</a> is revealing new clues about Earth’s earliest major mass extinction. The Late Ordovician mass extinction (LOME), was the first of the “big five" extinction events, during which about 85 percent of all <a href="https://www.earth.com/news/marine-species-vanishing/">marine species</a> were wiped out.&nbsp;



Today, many scientists believe that we are already in the midst of our planet's sixth mass extinction event as a result of human-induced climate change. It is critically important for scientists to understand the causes of previous die-offs in order to help prevent the same level of catastrophe in the future.&nbsp;



To investigate, an international team of researchers looked at the ocean environment before, during, and after the LOME. Professor Seth Finnegan, an expert in mass extinction at UC Berkeley, said the seas were full of biodiversity during the Ordovician Period. There were early reefs, but they lacked an abundance of vertebrates.



“If you had gone snorkeling in an Ordovician sea you would have seen some familiar groups like clams and snails and sponges, but also many other groups that are now very reduced in diversity or entirely extinct like trilobites, brachiopods and crinoids,” said Professor Finnegan.



He explained that unlike rapid mass extinctions, such as when dinosaurs and other species were suddenly wiped out around 65.5 million years ago, the LOME played out over a substantial period of time, with estimates between less than half a million to almost two million years.



One prevailing theory is that LOME was triggered by a lack of oxygen in the shallow ocean. The experts combined geochemical testing and computer modeling to test this theory.&nbsp;



Professor Zunli Lu led a team of students who measured iodine concentrations in carbonate rocks from the Ordovician Period. By studying concentrations of the element iodine in rocks, researchers can look for changes in oceanic oxygen levels at various ocean depths throughout Earth's history.



The results of the analysis produced no evidence that a lack of oxygen, or anoxia, caused the mass die-off. According to the researchers, it is much more likely that climate cooling during the Late Ordovician period was a major contributor to the LOME.



While there was no significant lack of oxygen in the shallow depths where animals dwelled, the team did find evidence that anoxia expanded at deep ocean depths. This is a mystery that cannot be explained by the classic model of ocean oxygen, explained study lead author Alexandre Pohl of UC Riverside.



“Upper-ocean oxygenation in response to cooling was anticipated, because atmospheric oxygen preferentially dissolves in cold waters,” said Pohl. “However, we were surprised to see expanded anoxia in the lower ocean since anoxia in Earth’s history is generally associated with volcanism-induced global warming.”



According to Lu, recognizing that climate cooling can also lead to lower oxygen levels in some parts of the ocean is a key takeaway from their study.



“For decades, the prevailing school of thoughts in our field is that global warming causes the oceans to lose oxygen and thus impact marine habitability, potentially destabilizing the entire ecosystem. In recent years, mounting evidence point to several episodes in Earth’s history when oxygen levels also dropped in cooling climates.”



The study does not fully explain the causes of Late Ordovician extinction, but the researchers have ruled out changes in oxygenation as the primary cause of the event. The research suggests that changes in temperature helped to set the stage for the Late Ordovician mass extinction, and the experts will continue to seek out additional factors that may have been involved.



The study is published in the journal <a href="https://www.nature.com/ngeo/">Nature Geoscience</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

New clues about Earth’s earliest major mass extinction

A study led by Syracuse University is revealing new clues...

New research led by the <a href="https://www.calpoly.edu/">California Polytechnic State University</a> (Cal Poly) has found that the loss of seagrass caused a dramatic shift in <a href="https://www.earth.com/news/when-fish-ingest-plastic-the-impacts-are-complicated/">fish</a> species in Morro Bay, California. The period following the decline of seagrass habitats was characterized by increases in flatfish and staghorn sculpin, and decreases in previous populations of bay pipefish and shiner perch.



Seagrass meadows were very common throughout the Morro Bay estuary and represented one of the most biologically productive biomes on Earth, providing shelter, food, and nurseries to a large variety of fish and invertebrate organisms. Following their significant decay in recent decades, they have been largely replaced currently with a less dynamic, muddy seafloor habitat.



"Seagrass, like the eelgrass in Morro Bay, is important because it supports a range of marine life," said study lead author Jennifer O'Leary, who is now the Western Indian Ocean coordinator for the <a href="https://www.wcs.org/">Wildlife Conservation Society</a>. "It's like the trees in a forest - these underwater plants provide food, structure, and shelter to many of the marine animals that live in the bay."



Morro Bay, one of the 28 estuaries that the <a href="https://www.epa.gov/">U.S. Environment Protection Agency</a> deemed critical for the environmental and economic health of the country, has witnessed a dramatic transformation.&nbsp; Seagrass declined by more than 95 percent, dropping from covering 344 acres in 2007 to only 15 acres in 2017.



Instead of resulting in fewer fish, seagrass loss has led to changes in the fish species that are present. The once common pipefish, a species perfectly adapted to hide among seagrass, has been replaced by flatfishes such as the speckled sanddab (Citharichthys stigmaeus) and the staghorn sculpin (Leptocottus armatus), which are more adapted to live among muddy seafloors.



"The relatively sudden and near complete collapse of eelgrass in Morro Bay has not only changed fish populations, but it has also resulted in substantial changes to estuary physics and geomorphology," added study co-author Ryan Walter, a professor of Physics at Cal Poly. The loss of seagrass in Morro Bay has led to widespread erosion, or loss of sediment, throughout the estuary.



According to the scientists, a multifaceted approach to protect the remaining seagrass is essential, including local planting initiatives and transplantation efforts.



The study is published in the journal <a href="https://link.springer.com/article/10.1007%2Fs12237-021-00917-2">Estuaries and Coasts</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Seagrass loss leads to changes in fish populations

New research led by the California Polytechnic State University (Cal...

During a routine analysis of biological samples from two male California condors in the <a href="https://sandiegozoowildlifealliance.org/">San Diego Zoo Wildlife Alliance</a>’s managed <a href="https://www.earth.com/news/cooperative-breeding-protects-desert-birds-from-reproductive-failure/">breeding</a> program, a team of conservation scientists reported an amazing discovery that could have a significant impact on wildlife genetics and conservation science. Both male condors had DNA that was 100 percent of their mothers, and were thus biologically fatherless.&nbsp;



This phenomenon is known as parthenogenesis and represents a natural form of asexual reproduction in which an embryo that is not fertilized by sperm continues to develop, containing only the mother’s genetic material. Parthenogenesis is very rare in birds, and usually occurs in females who have no access to males.



“This is truly an amazing discovery,” said study co-author Oliver Ryder, the director of Conservation Genetics at the San Diego Zoo Wildlife Alliance. “We were not exactly looking for evidence of parthenogenesis, it just hit us in the face. We only confirmed it because of the normal genetic studies we do to prove parentage. Our results showed that both eggs possessed the expected male ZZ sex chromosomes, but all markers were only inherited from their dams, verifying our findings.”&nbsp;



Previous examples of aviary parthenogenesis were only found domestic birds such as turkeys, finches, and domestic pigeons. Moreover, these birds did not have access to males. By contrast, the condor females had also produced a large number of offspring with their mates: one had 11 chicks, and the other - which was paired with a male for more than 20 years - had 23 chicks. 



"We believe that our findings represent the first instance of facultative avian parthenogenesis in a wild bird species, where both a male and a female are housed together,” said study co-author Cynthia Steiner, associate director for the conservation research division at San Diego Zoo Wildlife Alliance. “Still, unlike other examples of avian parthenogenesis, these two occurrences are not explained by the absence of a suitable male.”



Although these results represent only two documented cases in the condor population, the discovery could have important implications. Further research is needed to see whether parthenogenesis occurs in other condors, as well as in other species too.



The study is published in the <a href="https://academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esab052/6412509">Journal of Heredity</a>.&nbsp;



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

“Virgin births” discovered among California condors

During a routine analysis of biological samples from two male...

New research published in the journal <a href="https://link.springer.com/article/10.1007/s00265-021-03094-1">Behavioral Ecology and Sociobiology</a> has found that ground squirrels living off the coast of Africa keep watch together to defend against <a href="https://www.earth.com/news/a-new-study-led-by-the-memorial-university-of-newfoundland-in-canada-has-found-that-snowshoe-hares-are-starting-to-lose-their-camouflage-abilities-due-to-climate-change/">predators</a>. This strategy, called “synchronous vigilance," is different from that of other animals such as meerkats who take individual turns standing watch.



An international research team led by Dr. Annemarie van der Marel, a postdoctoral researcher at the <a href="https://www.uc.edu/">University of Cincinnati</a>, spent three winters studying the behavior of Barbary ground squirrels, an invasive species that was introduced to the Canary Islands from Morocco. These bushy-tailed rodents live in colonies and take shelter underground in a complex network of burrows.&nbsp;



“They’re pretty cute. People had them as pets and that’s how they were introduced to the Canary Islands in 1965,” said Dr. van der Marel. “I looked at whether and why they were social. I began studying the strategies for how they evade predation and increase survival. That’s how I got to the question of the synchronous vigilance of the species.”



Unusual for ground squirrels, the Canary Island populations seem to be as comfortable in trees as on the ground and prefer high vantage points from which to scan their surroundings. They face daily threats from predators such as buzzards, common kestrels, or even domestic cats.



“When they forage, they’re most vulnerable,” explained Dr. van der Marel. “So the squirrels have to balance the time spent foraging and being vigilant. Their main defense mechanism is being watchful and alerting other group members to escape predation.”



Throughout the day, these squirrels regularly stop their foraging activities in order to scan the environment together, often from a high vantage point. All squirrels stand watch each day, and although one-third of the time they do this alone, about 40 percent of the time they have company. When a predator is observed, even more squirrels stop to stand watch together.



The scientists found that squirrels’ extended vigilance does not affect their survival rates and gives them sufficient time to forage for food in order to remain in good physical condition.



“There are plentiful resources and less predation pressure, so they don’t have to forage as much,” Dr. van der Marel concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Barbary ground squirrels find safety in numbers

New research published in the journal Behavioral Ecology and Sociobiology...

When people hear the words "global warming," they often think of the polar ice caps melting, and the polar bears that suffer as a result. This raises questions about how rising <a href="https://www.earth.com/news/past-temperatures-are-revealed-by-the-size-of-animals/">temperatures</a> and sea ice loss are affecting the diets of polar bears, and how this information can be used to help protect them.



New research from York University has been exploring these exact questions, monitoring the eating habits and foraging locations of polar bears across the Arctic territory of Nunavut. The study has found that this data can be highly valuable as an indicator of environmental shifts, whilst also highlighting how diet changes can negatively affect prey populations and ecosystems in the Arctic.



Lead researchers Melissa Galicia and Professor Gregory Thiemann found that polar bears are actually flexible eaters, preying on whatever is readily available as opposed to the initial assumption that they mainly eat ringed and bearded seals. This flexibility makes them excellent candidates for monitoring environmental changes across the Arctic.



“Polar bears need the sea ice to hunt. When there is a reduction in the sea ice, they’re hunting less or they’re potentially hunting different prey species,” explained Galicia. “Prey species, like whales and seals, also need certain habitat conditions and because of environmental changes in the Arctic, some marine mammals, such as prey species of bears, are redistributing. You’re getting an increase in more sub-Arctic species, like killer whales for instance.”



The research was focused on harvest samples of polar bears that were provided by subsistence hunters over eight years. “I’m getting a large geographic representation of bears, especially in areas that tend to be less studied,” said Galicia, who was in charge of analyzing the fatty acids such as omega 3s and omega 6s that are found in the fat tissues of polar bears.



“Each bear will have a specific fatty acid signature, a kind of fingerprint for individual bears and because of that you can see what that particular individual is eating and what percentage of their diet that represents.”



Bowhead whale carcasses were identified commonly in the polar bears’ diets, which suggests that the whales are venturing further north for longer periods of time as a result of global warming. Habitat changes like this are likely to increase in frequency due, particularly within the Arctic ecosystem which is experiencing changes up to three times faster than other regions.



“As temperatures across the Arctic warm and sea ice loss increases, there will be profound cascading ecological consequences. What’s not known is how that will affect species, such as seals and whales, but by monitoring the seasonal prey consumption of polar bears, scientists can better keep track of where marine mammal prey species are showing up and their seasonal distribution,” explained Thiemann.



The research is published in the journal&nbsp; <a href="https://www.sciencedirect.com/journal/ecological-indicators">Ecological Indicators</a>.



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By <a href="mailto:calumvaughan05@gmail.com">Calum Vaughan</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Polar bear diets reflect environmental changes

When people hear the words "global warming," they often think...

An international team of scientists has recently launched an ambitious initiative to listen to, contextualize, and translate the <a href="https://www.earth.com/news/computer-models-can-mimic-human-language-processing/">language</a> of sperm whales, with the final goal of managing to establish communication with these majestic marine mammals.&nbsp;The research is known as Project CETI (the Cetacean Translation Initiative).



In order to accomplish this goal, scientists will use state-of-the-art machine learning and non-invasive robotics to listen and translate the whales’ language before attempting to communicate with them.&nbsp;



The sperm whale has the largest brain on Earth (more than five times heavier than the human brain), lives in tightly knit family groups, and has a complex communication system. The whales are vital to our environment since they support oxygen supply and keep carbon out of the atmosphere.



“These animals make a clicking sound at varying frequencies when they are in the company of other whales. The question is, is this just a simple code or a true language?” pondered project co-leader Dan Tchernov, a professor of Marine Biology at the <a href="https://www.haifa.ac.il/?lang=en">University of Haifa</a>.&nbsp;



“Right now, our database is not comprehensive enough to know the answer to this question. However, with the advancement of machine learning, and advanced linguistics, we realized that if we gathered enough data about their voices, the context in which these sounds are employed and understood and their behavior and motivation behind these sounds, we can then develop an algorithm which will determine whether they have an authentic language.”



During a period of five years, Project CETI will bring together an international team of cryptographers, roboticists, linguists, marine biologists, and technologists in order to develop non-invasive devices and employ them to collect and interpret the sounds made by a large number of sperm whales. According to Professor Tchernov, the ultimate goal of this project would be to communicate with the whales, on their own terms.



“Project CETI is a human journey into our relationship with other creatures on the planet,” said the project’s founder and leader David Gruber, a professor of Biology and Environmental Sciences at the<a href="https://www.cuny.edu/"> City University of New York</a>.&nbsp;



“Through an understanding of a non-human species and the power of collaborative research, we are hoping to ignite a worldwide movement to reshape our relationship with life on Earth and connect to and learn from nature.”



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

New project aims to help humans talk to whales

An international team of scientists has recently launched an ambitious...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Flu viruses are more flexible than expected

[sendtonews key="G9bUoxcjr4-2511624-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

How does salt makes things taste better?

[sendtonews key="X0f6OHYoI4-2310561-12187" type="single"] Today’s Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

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Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

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Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

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