Rethinking the dodo

Researchers are setting out to challenge our misconceptions about the Dodo, one of the most well-known but poorly understood species of bird.

In a paper published today [16 August 2024] in the Zoological Journal of the Linnean Society researchers from the University of Southampton, Natural History Museum (NHM) and Oxford University Museum of Natural History have undertaken the most comprehensive review of the taxonomy of the Dodo and its closest relative, the Rodriguez Island Solitaire.

They've painstakingly gone through 400 years' worth of scientific literature and visited collections around the UK to ensure this iconic species, embodying humanity's destructive potential, is correctly classified.

"The Dodo was the first living thing that was recorded as being present and then disappeared," says Dr Neil Gostling from the University of Southampton, supervising author of the paper. "Before this, it hadn't been thought possible for human beings to influence God's creation in such a way.

"This was a time before the scientific principles and systems we rely on to label and classify a species were in place. Both the Dodo and the Solitaire were gone before we had a chance to understand what we were looking at."

Correcting the record

Much of what was written about the Dodo and the Solitaire was based on accounts from Dutch sailors, representations by artists, and incomplete remains.

The lack of a definitive reference point (type specimen) or convention to label species (zoological nomenclature) led to a series of misidentifications in the centuries following their extinction. New species such as the Nazarene Dodo, the White Dodo, and the White Solitaire were named, but the paper confirms that none of these creatures existed. Still, these erroneous 'pebbles' sent ripples through the waters of zoological literature.

"By the 18th and early 19th centuries, the Dodo and the Solitaire were considered to be mythological beasts," says Dr Mark Young, lead author of the paper from the University of Southampton. "It was the hard work of Victorian-era scientists who finally proved that the Dodo and the Solitaire were not mythological but were giant ground doves."

"Unfortunately, no one could agree how many species there had been," continues Dr Young. "Throughout most of the 19th and 20th centuries, researchers thought there were three different species, although some people thought there had been four or even five different species."

To unpick this confusion, researchers went through all the literature on the Dodo and Rodriguez Solitaire encompassing hundreds of accounts dating back to 1598 and visited specimens around the UK, including the world's only surviving soft tissue from the Dodo, in the Oxford Museum.

"More has been written about the Dodo than any other bird, yet virtually nothing is known about it in life," says Dr Julian Hume, an avian palaeontologist at the Natural History Museum and coauthor of the paper.

"Based on centuries of nomenclatural confusion, and some 400 years after its extinction, the Dodo and Solitaire, continue to prompt heated debate. We've gone from where the first statements were made, seen how these have developed, and identified various rabbit holes to correct the record, as best we can."

Through this work, researchers were able to confirm that both birds were members of the columbid (pigeon and dove) family.

"Understanding its wider relationships with other pigeons is of taxonomic importance, but from the perspective of conservation, the loss of the dodo and the solitaire a few decades later means a unique branch of the pigeon family tree was lost," says Dr Gostling. "There are no other birds alive today like these two species of giant ground dove."

Challenging our misconceptions

The researchers believe the popular idea of the Dodo as a fat, slow animal, predestined for extinction is flawed.

"Even four centuries later, we have so much to learn about these remarkable birds," says Dr Young. "Was the Dodo really the dumb, slow animal we've been brought up to believe it was? The few written accounts of live Dodos say it was a fast-moving animal that loved the forest."

Dr Gostling adds: "Evidence from bone specimens suggests that the Dodo's tendon which closed its toes was exceptionally powerful, analogous to climbing and running birds alive today. The dodo was almost certainly a very active, very fast animal.

"These creatures were perfectly adapted to their environment, but the islands they lived on lacked mammalian predators. So, when humans arrived, bringing rats, cats, and pigs, the Dodo and the Solitaire never stood a chance.

"Dodos held an integral place in their ecosystems. If we understand them, we might be able to support ecosystem recovery in Mauritius, perhaps starting to undo the damage that began with the arrival of humans nearly half a millennium ago."

Learning 'valuable lessons'

The study marks the beginning of a wider project to understand the biology of these iconic animals.

"The mystery of the Dodo bird is about to be cracked wide open," says Dr Markus Heller, Professor of Biomechanics at the University of Southampton, a coauthor on the paper.

"We have assembled a fantastic team of scientists to uncover the true nature of this famous extinct bird. But we are not just looking back in time -- our research could help save today's endangered birds too."

Dr Heller explains: "Using cutting-edge computer technology, we are piecing together how the Dodo lived and moved. This isn't just about satisfying our curiosity. By understanding how birds evolved in the past, we are learning valuable lessons that could help protect bird species today."

"It's like solving a 300-year-old puzzle, and the solution might just help us prevent more birds from going the way of the Dodo."

The project will include work with palaeoartist Karen Fawcett, who has created a detailed, life-size model of the Dodo to bring the words on the pages of books and journal articles to life. She says: "This work has been the merging of science and art to achieve accuracy and realism so that these creatures come back from the dead, real and tangible for people to touch and see."

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How can forests be reforested in a climate-friendly way?

Europe's forests have already been severely affected by climate change. Thousands of hectares of trees have already died due to drought and bark beetles. Scientists from the University of Vienna and the Technical University of Munich TUM have now investigated which trees can be used for reforestation. Their findings: only a few tree species are fit for the future, such as English oak in the UK. However, mixed forests are important for the survival of forests, otherwise the forest ecosystem as a whole could be weakened. The results of the study were recently published in the renowned journal Nature Ecology and Evolution.

Although European forests are naturally home to a mix of trees, the number of tree species is lower than in climatically comparable areas of North America or East Asia. In the future, even fewer species will be available to the forestry industry, as scientists led by Johannes Wessely and Stefan Dullinger from the University of Vienna have shown in their new study. Depending on the region, between a third and a half of the tree species found there today will no longer be able to cope with future conditions. "This is an enormous decline," says lead author Johannes Wessely, "especially when you consider that only some of the species are of interest for forestry."

The scientists examined the 69 more common of the just over 100 European tree species with regard to the 21st century in Europe. On average, only nine of these 69 species per location are fit for the future in Europe, compared to four in the UK. "Trees that are planted now for reforestation must survive under both current and future conditions. This is difficult because they have to withstand the cold and frost of the next few years as well as a much warmer climate at the end of the 21st century. There is only a very small overlap," says Wessely. In the UK, these climate-fit species include, for example, the English oak. Which tree species will suit which region of Europe in the future varies greatly overall.

Forest ecosystem at risk due to restriction of species

However, even with the selected set of future-proof trees, a major problem remains: the average of nine species is not enough for a species-rich mixed forest. "Mixed forests consisting of many tree species are an important measure to make forests more robust against disturbances such as bark beetles. In some places in Europe, however, we could run out of tree species to establish such colorful mixed forests," explains last author Rupert Seidl from the Technical University of Munich TUM.

Not all trees offer important properties

Trees store carbon, provide a habitat or food source for animals or can be processed into timber -- these are all important properties of forests. But not all trees fulfill these functions equally; only an average of three of the nine climate-fit tree species can do this.

"Our work clearly shows how severely the vitality of forests is affected by climate change. We cannot rely solely on a new mix of tree species; rapid measures to mitigate climate change are essential for the sustainable protection of our forests," says Wessely.

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Landscape dynamics determine the evolution of biodiversity on Earth

Movement of rivers, mountains, oceans and sediment nutrients at the geological timescale are the central drivers of Earth's biodiversity, new research published today in Nature has revealed.

The research also shows that biodiversity evolves at similar rates to the pace of plate tectonics, the slow geological processes that drive the shape of continents, mountains and oceans.

"That is a rate incomparably slower than the current rates of extinction caused by human activity," said lead author Dr Tristan Salles from the School of Geosciences.

The research looks back over 500 million years of Earth's history to the period just after the Cambrian explosion of life, which established the main species types of modern life.

Dr Salles said: "Earth's surface is the living skin of our planet. Over geological time, this surface evolves with rivers fragmenting the landscape into an environmentally diverse range of habitats.

"However, these rivers not only carve canyons and form valleys, but play the role of Earth's circulatory system as the main conduits for nutrient and sediment transfer from sources (mountains) to sinks (oceans).

"While modern science has a growing understanding of global biodiversity, we tend to view this through the prism of narrow expertise," Dr Salles said. "This is like looking inside a house from just one window and thinking we understand its architecture.

"Our model connects physical, chemical and biological systems over half a billion years in five-million-year chunks at a resolution of five kilometres. This gives an unprecedented understanding of what has driven the shape and timing of species diversity," he said.

The discovery in 1994 of the ancient Wollemi pine species in a secluded valley in the Blue Mountains west of Sydney gives us a glimpse into the holistic role that time, geology, hydrology, climate and genetics play in biodiversity and species survival.

The idea that landscapes play a role in the trajectory of life on Earth can be traced back to German naturalist and polymath Alexander von Humboldt. His work inspired Charles Darwin and Alfred Wallace, who were the first to note that animal species boundaries correspond to landscape discontinuities and gradients.

"Fast forwarding nearly 200 years, our understanding of how the diversity of marine and terrestrial life was assembled over the past 540 million years is still emerging," University of Sydney PhD student Beatriz Hadler Boggiani said.

"Biodiversity patterns are well identified from the fossil record and genetic studies. Yet, many aspects of this evolution remain enigmatic, such as the 100 million years delay between the expansion of plants on continents and the rapid diversification of marine life."

In groundbreaking research a team of scientists -- from the University of Sydney, ISTerre at the French state research organisation CNRS and the University of Grenoble Alpes in France -- has proposed a unified theory that connects the evolution of life in the marine and terrestrial realms to sediment pulses controlled by past landscapes.

"Because the evolution of the Earth's surface is set by the interplay between the geosphere and the atmosphere, it records their cumulative interactions and should, therefore, provide the context for biodiversity to evolve," said Dr Laurent Husson from University of Grenoble Alpes.

Instead of considering isolated pieces of the environmental puzzle independently, the team developed a model that combines them and simulates at high resolution the compounding effect of these forces.

"It is through calibration of this physical memory etched in the Earth's skin with genetics, fossils, climate, hydrology and tectonics by which we have investigated our hypothesis," Dr Salles said.

Using open-source scientific code published by the team in Science in March, the detailed simulation was calibrated using modern information about landscape elevations, erosion rates, major river waters and the geological transport of sediment (known as sediment flux).

This allowed the team to evaluate their predictions over 500 million years using a combination of geochemical proxies and testing different tectonic and climatic reconstructions. The geoscientists then compared the predicted sediment pulses to the evolution of life in both the marine and terrestrial realms obtained from a compilation of paleontological data.

"In a nutshell, we reconstructed Earth landforms over the Phanerozoic era, which started 540 million years ago, and looked at the correlations between the evolving river networks, sediment transfers and known distribution of marine and plant families," University of Grenoble PhD student Manon Lorcery said.

When comparing predicted sediment flux into the oceans with marine biodiversity, the analysis shows a strong, positive correlation.

On land, the authors designed a model integrating sediment cover and landscape variability to describe the capacity of the landscape to host diverse species. Here again, they found a striking correlation between their proxy and plant diversification for the past 450 million years.

In his 1864 novel A Journey to the Centre of the Earth, Jules Verne attributes this to his fictitious hero, Professor Otto Lidenbrock:

"Animal life existed upon the Earth only in the secondary period, when a sediment of soil had been deposited by the rivers and taken the place of the incandescent rocks of the primitive period."

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Killing remains a threat to Bornean orangutans

University of Queensland research has found despite considerable conservation efforts, the illegal killing of critically endangered orangutans on Borneo may be an ongoing threat to the species.

PhD candidate Emily Massingham from UQ's Faculty of Science managed a team of researchers which visited 79 villages across the Bornean orangutan range in Kalimantan, conducting face to face interviews with 431 people.

"Our study builds on previous research which indicated killing was one of the key reasons for orangutan population decline, alongside habitat loss," Ms Massingham said.

"The aim of our project was to understand whether orangutans have been killed in recent times, to look at whether conservation projects are effectively preventing killing, and to gain insights into community perceptions and the motivations behind it.

"It has been almost 15 years since the previous study, and we did not find a clear decrease in killings despite Indonesia's commendable efforts to reduce habitat loss.

"Thirty per cent of villages reported orangutans had been killed in the last 5 -10 years, despite the practice being both illegal and taboo -- which also makes it hard to get an accurate picture of the true scale."

Ms Massingham said Borneo's orangutan population had decreased by 100,000 in recent decades, with current estimates suggesting fewer than 100,000 animals remain.

"Our findings did not indicate that conservation projects are reducing killing, highlighting an urgent need to improve the collective approach to orangutan conservation," she said.

"Killing by humans needs to be addressed, as our findings suggest it may still be occurring and poses a real threat to the species."

Ms Massingham said orangutans have long lifespans and breed slowly, so are particularly vulnerable to population declines driven by the death of adult apes.

"Our interviews revealed some of the situations which lead to the killing or displacement of individual orangutans," she said.

"They include protecting crops and taking infant apes to keep as pets."

The researchers outlined recommendations that could improve future conservation efforts.

"Working with communities and collaborating across disciplines and projects will be key," Ms Massingham said.

"Conservationists need to work closely with individual villages to understand their needs and perspectives, identify the social drivers of killing of orangutans and implement solutions that reduce human-orangutan conflict."

Read more at Science Daily

Fossil spines reveal deep sea's past

Right at the bottom of the deep sea, the first very simple forms of life on earth probably emerged a long time ago. Today, the deep sea is known for its bizarre fauna. Intensive research is being conducted into how the number of species living on the sea floor have changed in the meantime. Some theories say that the ecosystems of the deep sea have emerged again and again after multiple mass extinctions and oceanic upheavals. Today's life in the deep sea would thus be comparatively young in the history of the Earth. But there is increasing evidence that parts of this world are much older than previously thought.

A research team led by the University of Göttingen has now provided the first fossil evidence for a stable colonisation of the deep sea floor by higher invertebrates for at least 104 million years. Fossil spines of irregular echinoids (sea urchins) indicate their long-standing existence since the Cretaceous period, as well as their evolution under the influence of fluctuating environmental conditions. The results have been published in the journal PLOS ONE.

The researchers examined over 1,400 sediment samples from boreholes in the Pacific, Atlantic and Southern Ocean representing former water depths of 200 to 4,700 metres. They found more than 40,000 fragments of spines, which they assigned to a group called irregular echinoids, based on their structure and shape. For comparison, the scientists recorded morphological characteristics of the spines, such as shape and length, and determined the thickness of around 170 spines from each of two time periods. As an indicator of the total mass of the sea urchins in the habitat -- their biomass -- they determined the amount of spiny material in the sediments.

What these fossil spines document is that the deep sea has been continuously populated by irregular echinoids since at least the early Cretaceous period about 104 million years ago. And they provide further exciting insights into the past: the devastating meteorite impact at the end of the Cretaceous period about 66 million years ago, which resulted in a worldwide mass extinction -- with the dinosaurs as the most prominent victims -- also caused considerable disturbances in the deep sea. This is shown by the morphological changes in the spines: they were thinner and less diverse in shape after the event than before. The researchers interpret this as the "Lilliput Effect." This means that smaller species have a survival advantage after a mass extinction, leading to the smaller body size of a species. The cause could have been the lack of food at the bottom of the deep sea.

"We interpret the changes in the spines as an indication of the constant evolution and emergence of new species in the deep sea," explains Dr Frank Wiese from the Department of Geobiology at the University of Göttingen, the lead author of the study. He emphasises another finding: "About 70 million years ago, the biomass of sea urchins increased. We know that the water cooled down at the same time. This relationship between biomass in the deep sea and water temperature allows us to speculate how the deep sea will change due to human-induced global warming."

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Most species are rare, but not very rare

More than 100 years of observations in nature have revealed a universal pattern of species abundances: Most species are rare but not very rare, and only a few species are very common. These so-called global species abundance distributions have become fully unveiled for some well-monitored species groups, such as birds. For other species groups, such as insects, however, the veil remains partially unlifted. These are the findings of an international team of researchers led by the German Centre for Integrative Biodiversity Research (iDiv), the Martin Luther University Halle-Wittenberg (MLU) and the University of Florida (UF), published in the journal Nature Ecology and Evolution. The study demonstrates how important biodiversity monitoring is for detecting species abundances on planet Earth and for understanding how they change.

"Who can explain why one species ranges widely and is very numerous, and why another allied species has a narrow range and is rare?" This question was asked by Charles Darwin in his ground-breaking book "The Origin of Species," published over 150 years ago. A related challenge has been to understand how many species are common (numerous) and how many are rare, the so-called global species abundance distribution (gSAD).

Two main gSAD models have been proposed in the last century: R. A. Fisher, a statistician and biologist, proposed that most species are very rare and that the number of species declines for more common species (so-called log-series model). On the other hand, F. W. Preston, an engineer and ecologist, argued that only few species are actually very rare and that most species have some intermediate level of commonness (so-called log-normal model). However, until now and despite decades of research, scientists did not know which model describes the planet's true gSAD.

Solving this problem calls for vast amounts of data. The study authors used data from the Global Biodiversity Information Facility (GBIF) and downloaded data representing over 1 billion species observations in nature from 1900 to 2019.

"The GBIF database is an amazing resource for all sorts of biodiversity related research, particularly because it brings together both data collected from professional and citizen scientists all over the world," says first author Dr Corey Callaghan. He began the study while working at iDiv and MLU and is now working at the UF.

Callaghan and his fellow researchers divided the downloaded data into 39 species groups, for instance, birds, insects, or mammals. For each, they compiled the respective global species abundance distribution (gSAD).

The researchers detected a potentially universal pattern, which emerges once the species abundance distribution is fully unveiled: Most species are rare but not very rare, and only a few species are very common, as predicted in the log-normal model. However, the researchers also found that the veil has been fully lifted only for a few species groups like cycads and birds. For all other species groups, the data are yet insufficient.

"If you don't have enough data, it looks as though most species are very rare," says senior author Prof Henrique Pereira, research group head at iDiv and the MLU. "But by adding more and more observations, the picture changes. You start seeing that there are, in fact, more rare species than very rare species. You can see this shift for cycads and birds when comparing the species observations from back in 1900, when less data was available, with the more comprehensive species observations we have today. It is fascinating: we can clearly see the phenomenon of unveiling the full species abundance distribution, as predicted by Preston several decades ago, but only now demonstrated at the scale of the entire planet."

"Even though we have been recording observations for decades, we have only lifted the veil for a few species groups," says Callaghan. "We still have a long way to go. But GBIF and the sharing of data really represents the future of biodiversity research and monitoring, to me."

The new study's findings enable scientists to assess how far the gSADs have been unveiled for different species groups. This allows for answering another long-standing research question: How many species are out there? This study finds that while for some groups like birds, nearly all species have been identified, this is not the case for other taxa such as insects and cephalopods.

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Historic red tide event of 2020 fueled by plankton super swimmers

A major red tide event occurred in waters off Southern California in the spring of 2020, resulting in dazzling displays of bioluminescence along the coast. The spectacle was caused by exceedingly high densities of Lingulodinium polyedra (L. polyedra),a plankton species renowned for its ability to emit a neon blue glow. While the red tide captured the public's attention and made global headlines, the event was also a harmful algal bloom. Toxins were detected at the height of the bloom that had the potential to harm marine life, and dissolved oxygen levels dropped to near-zero as the extreme biomass of the red tide decomposed. This lack of oxygen led to fish die-offs and other destructive impacts on local ecosystems.

Now, for the first time, a study led by scientists at UC San Diego's Scripps Institution of Oceanography and Jacobs School of Engineering has pinpointed how this plankton species -- a dinoflagellate -- was able to create such an exceptionally dense bloom. The answer lies in dinoflagellates' remarkable ability to swim, which lends them a competitive advantage over other species of phytoplankton. According to the authors, this swimming ability can lead to the formation of dense blooms, including those of the bioluminescent variety.

"The idea that vertical swimming gives dinoflagellates a competitive advantage actually goes back more than half a century, but only now do we have the technology to conclusively prove it in the field," said oceanographer Drew Lucas, senior author of the paper and an associate professor at Scripps Oceanography and the Department of Mechanical and Aerospace Engineering at UC San Diego.

Lucas and former graduate student Bofu Zheng led the work alongside several colleagues in the midst of the red tide event in April and May 2020. The researchers seized the opportunity to deploy sophisticated ocean instruments off the coast of San Diego, resulting in unprecedented measurements. The effort was made possible with funding provided by the Southern California Coastal Ocean Observing System (SCCOOS) through an award by the National Oceanic and Atmospheric Administration (NOAA). The team's findings were published in the Aug. 28 issue of the Proceedings of the National Academy of Sciences, showcased as the cover story.

The dinoflagellates -- L. polyedra specifically -- were shown to be highly mobile, swimming upward during the day to photosynthesize and downward at night to access a deep nutrient pool. This resulted in the intensified ruddy coloration of the water at the surface, hence the term "red tide," seen most prominently in the afternoon. A large population of the dinoflagellates was documented making the downward journey at night, though a portion remained near the surface waters, leading to nighttime displays of bioluminescence. The authors found that this vertical migration is what allowed the dinoflagellates to outgrow their non-mobile competitors, including other species of phytoplankton.

The study validates a 50-year-old hypothesis originally presented by Scripps Oceanography biological oceanographer Richard "Dick" Eppley. He and colleagues posited that the vertical migration of dinoflagellates was linked to harmful algal blooms, which have been documented off Southern California for at least 120 years. Extensive lab research was conducted to support this idea, but it had never been tested in the field until the 2020 event.

As in many dinoflagellate species, L. polyedra is endowed with a pair of flagella -- whip-like appendages that propel the single-celled organism through the water. In addition to its ability to swim, L. polyedra is remarkably fast, with a maximum swimming speed of up to 10 body lengths per second for almost 24 hours.

"In the plankton world, they are Michael Phelps," said Lucas, describing the dinoflagellates. "For comparison, fast-burst swimming in species like bluefin tuna or shortfin mako is around 9-10 body lengths per second, but only for very short periods. Their exceptional swimming allows L. polyedra to dive to cold depths where they can take up nutrients, allowing these organisms to really bloom and explode in population."

The team used the Wirewalker -- an autonomous, ocean-wave-powered vertical profiling system that was developed at Scripps Oceanography -- to continuously measure physical and biochemical conditions from the sea surface to the seafloor, reaching a depth of 100 meters (300 feet). Powered by wave energy, the instrument moves up and down a mooring line attached to a buoy, while taking measurements of temperature, salinity, depth, sunlight levels, chlorophyll fluorescence, and nitrate concentrations. They also captured near-surface images of the bloom using an Imaging FlowCytobot (IFCB), a robotic microscope installed on an offshore mooring; this site is now part of a larger IFCB network overseen by SCCOOS.

Data and images collected by these instruments validated Eppley's original hypothesis, showing that indeed L. polyedra descended at dusk, reaching a maximum depth of about 30-40 meters (100-130 feet) after 18 to 24 hours of swimming. While in the deep, the dinoflagellates would take up nitrate, which acts as a growth nutrient for plankton, before returning to the surface around noon to photosynthesize during maximum sunlight.

The growth of phytoplankton biomass, or the "bloom," correlated with proportional decreases in nitrate concentrations at depth, linking the important role that swimming phytoplankton have in the development of certain types of red tides. On cloudy days, the subsurface vertical migration was much less apparent, suggesting that the intensity of sunlight is an important trigger for vertical migration.

Lead author Zheng, now a postdoctoral investigator at Woods Hole Oceanographic Institution (WHOI), was impressed by the many advanced functions of the dinoflagellates, which are comparable in size to the diameter of a human hair.

"These single-celled organisms, namely L. polyedra, are so functionally complex and amazing," said Zheng. "In addition to their swimming speed, which is far beyond human limits, they can coordinate their behavior according to the day-night cycle by migrating down at night and coming back to the ocean surface during the day; they can produce spectacular bioluminescence; they can photosynthesize; they can even prey on organisms that are smaller than them."

The researchers also looked at long-term ocean monitoring data captured by the California Cooperative Oceanic Fisheries Investigations (CalCOFI), and long-term mooring data maintained by the Ocean Time-Series Group at Scripps Oceanography to see other consequences from the bloom. Looking at more than 70 years of climate data, the results showed that the bloom created physical and chemical conditions in the water column that deviated from the norm, showing the potential for massive blooms to alter characteristics of the coastal ocean.

Study co-author and SCCOOS director Clarissa Anderson said this research stands out for its use of novel ocean technologies, which allowed for unparalleled measurements of how phytoplankton respond to small-scale changes in the coastal ocean, as well as calculations of nutrient uptake by dinoflagellates at such fine scales. She also noted the importance of long-term observations as being key to any future efforts to better understand harmful algal blooms.

"The more we understand complex mechanisms that allow a particular species or population of plankton to thrive and persist, the better we can predict runaway events like the 2020 red tide that lasted much longer than theory might dictate," said Anderson, who is also a biological oceanographer at Scripps Oceanography. "With longer time series of rapid change in coastal nutrient delivery, circulation, light regimes, and algal toxins, we could build more accurate dynamical models for predicting plankton blooms, including those that turn harmful."

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Wastewater pipe dig reveals 'fossil treasure trove'

A new New Zealand Journal of Geology and Geophysics paper out today describes the 266 fossil species as one of the richest and most diverse groups of three-million-year-old fauna ever found in New Zealand. At least ten previously unknown species will be described and named in future research.

Fossil treasure trove from Auckland's Mangere Wastewater Treatment Plant

In 2020, when Auckland's Watercare were excavating two huge vertical shafts for a major upgrade of the major pipeline that brings raw sewage for treatment from the central city they dug through an ancient shell bed. Auckland paleontologist Bruce Hayward likened it to "finding gold right on your door step." Once they were informed of the fossil deposit's significance, Watercare and their contractors were eager to help and a huge heap of shelly sand was dumped in a nearby paddock so that paleontologists could search through it over many months. Watercare also funded two paleontology graduate students, working under the supervision of Auckland Museum curator Dr Wilma Blom, to painstakingly sift through the heap for many weeks. As a result, it is estimated that over 300,000 fossils were examined and several thousand have been returned in the museum as a record of this "once-in-a-lifetime find."

"Detailed identification of the fossils shows that they were deposited between 3 and 3.7 million years ago in a subtidal channel in an early version of the modern Manukau Harbour," said Dr Hayward. "At that time, sea level was slightly higher than it is today as the world was also several degrees warmer than now. As a result, the fossils include a number of subtropical species, whose relatives today live in the warmer waters around the Kermadec and Norfolk islands. At least ten previously unknown species are present and will be described and named in future work."

In their scientific paper that appeared this week in the New Zealand Journal of Geology and Geophysics, the five authors record 266 different fossil species, making it the richest and most diverse fauna of its age ever found in New Zealand. "What is surprising," says lead author Dr Hayward "is that the fauna contains fossils that lived in many different environments that have been brought together in the ancient marine channel by wave action and strong tidal currents. It includes ten specimens of the iconic NZ flax snail that must have lived on the adjacent land and been washed down into the sea by storm runoff. These are by far the oldest known flax snails in the world. Most of the fossils lived on the sea floor, some in brackish estuaries, others attached to hard rocky shorelines and still more have been carried in from offshore of the exposed west coast at the time."

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Oldest known species of swimming jellyfish identified

Royal Ontario Museum (ROM) announces the oldest swimming jellyfish in the fossil record with the newly named Burgessomedusa phasmiformis. These findings are announced in the journal Proceedings of the Royal Society B.

Jellyfish belong to medusozoans, or animals producing medusae, and include today's box jellies, hydroids, stalked jellyfish and true jellyfish. Medusozoans are part of one of the oldest groups of animals to have existed, called Cnidaria, a group which also includes corals and sea anemones. Burgessomedusa unambiguously shows that large, swimming jellyfish with a typical saucer or bell-shaped body had already evolved more than 500 million years ago.

Burgessomedusa fossils are exceptionally well preserved at the Burgess Shale considering jellyfish are roughly 95% composed of water. ROM holds close to two hundred specimens from which remarkable details of internal anatomy and tentacles can be observed, with some specimens reaching more than 20 centimetres in length. These details enable classifying Burgessomedusa as amedusozoan. By comparison with modern jellyfish, Burgessomedusa would also have been capable of free-swimming and the presence of tentacles would have enabled capturing sizeable prey.

"Although jellyfish and their relatives are thought to be one of the earliest animal groups to have evolved, they have been remarkably hard to pin down in the Cambrian fossil record. This discovery leaves no doubt they were swimming about at that time," said co-author Joe Moysiuk, a Ph.D. candidate in Ecology & Evolutionary Biology at the University of Toronto, who is based at ROM.

This study, identifying Burgessomedusa, is based on fossil specimens discovered at the Burgess Shale and mostly found in the late 1980s and 1990s under former ROM Curator of Invertebrate Palaeontology Desmond Collins. They show that the Cambrian food chain was far more complex than previously thought, and that predation was not limited to large swimming arthropods like Anomalocaris (see field image showing Burgessomedusa and Anomalocaris preserved on the same rock surface).

"Finding such incredibly delicate animals preserved in rock layers on top of these mountains is such a wonderous discovery. Burgessomedusa adds to the complexity of Cambrian foodwebs, and like Anomalocaris which lived in the same environment, these jellyfish were efficient swimming predators," said co-author, Dr. Jean-Bernard Caron, ROM's Richard Ivey Curator of Invertebrate Palaeontology. "This adds yet another remarkable lineage of animals that the Burgess Shale has preserved chronicling the evolution of life on Earth."

Cnidarians have complex life cycles with one or two body forms, a vase-shaped body, called a polyp, and in medusozoans, a bell or saucer-shaped body, called a medusa or jellyfish, which can be free-swimming or not. While fossilized polyps are known in ca. 560-million-year-old rocks, the origin of the free-swimming medusa or jellyfish is not well understood. Fossils of any type of jellyfish are extremely rare. As a consequence, their evolutionary history is based on microscopic fossilized larval stages and the results of molecular studies from living species (modelling of divergence times of DNA sequences). Though some fossils of comb-jellies have also been found at the Burgess Shale and in other Cambrian deposits, and may superficially resemble medusozoan jellyfish from the phylum Cnidaria, comb-jellies are actually from a quite separate phylum of animals called Ctenophora. Previous reports of Cambrian swimming jellyfish are reinterpreted as ctenophores.

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Why there are no kangaroos in Bali (and no tigers in Australia)

If you travel to Bali, you won't see a cockatoo, but if you go to the neighbouring island of Lombok, you will. The situation is similar with marsupials: Australia is home to numerous marsupial species, such as the kangaroo and the koala. The further west you go, the sparser they become. While you will find just two representatives of these typically Australian mammals on the Indonesian island of Sulawesi, you will search in vain for them on neighbouring Borneo. Australia, on the other hand, is not home to mammals that you will typically find in Asia, such as bears, tigers or rhinos.

This abrupt change in the composition of the animal world already caught the eye of the British naturalist and co-discoverer of evolutionary theory Alfred Russell Wallace, who travelled through the Indo-Australian Archipelago from 1854 to 1862 to collect animals and plants. He described an (invisible) biogeographical line running between Bali and Lombok and Borneo and Sulawesi that marked the westernmost distribution of Australian fauna.

Fascinating change of wildlife

Biodiversity researchers have long been fascinated by this abrupt change of creatures along the Wallace Line. How these distribution patterns came about, however, has not yet been clarified in detail.

One explanation is plate tectonics. Forty-five million years ago, the Australian Plate began to drift northwards and slid under the mighty Eurasian Plate. This brought two land masses closer together that had previously been far apart. It became easier for land creatures to colonise one continent from the other. Tectonic movements also gave rise to the creation of countless (volcanic) islands between the two continents, which animals and plants used as stepping stones to migrate westwards or eastwards.

More Asian animals in Australia than vice versa

But why more species found their way from Asia to Australia -- countless poisonous snakes, thorny lizards (Moloch horridus), hopping mice (Notomys sp.) or flying foxes bear witness to this -- than the other way round has been a mystery until now.

In order to better understand this asymmetrical vertebrate distribution along the Wallace Line, researchers led by Loïc Pellissier, Professor of Ecosystems and Landscape Evolution at ETH Zurich, have created a new model. It combines reconstructions of the climate, plate displacements between 30 million years ago and the present day and a comprehensive data set for around 20,000 birds, mammals, reptiles and amphibians that are recorded in the region today.

Climates in areas of origin decisive

In the latest issue of Science, the researchers now show that adaptations to the climates in the areas of origin are partly responsible for the uneven distribution of Asian and Australian faunal representatives on both sides of the Wallace Line.

In addition to plate tectonics, the environmental conditions that prevailed millions of years ago were decisive for the exchange between the two continents. Based on simulations, the researchers found that animals originating from Asia were more likely to "hop" across the Indonesian islands to reach New Guinea and northern Australia.

These islands featured a tropically humid climate, which they were comfortable with and had already adapted to. The Australian wildlife was different, having evolved in a cooler climate that had become increasingly drier over time, and was therefore less successful in gaining a foothold on the tropical islands than the fauna migrating from Asia.

The Asian climate thus favoured creatures that reached Australia via the tropical islands of the faunal region known as Wallacea, especially those that could tolerate a wide range of climates. This made it easier for them to settle on the new continent. "The historical context is crucial for understanding the biodiversity distribution patterns observed today and was the missing piece of the puzzle explaining the enigma of Wallace's line," says first author Alexander Skeels, a postdoctoral researcher in Pellissier's group.

Competitive advantages for tropical species

Traits of species that evolved in tropical habitats include faster growth and higher competitiveness to enable them to withstand the pressure of coexistence with many other species. In harsher climates, such as the colder and drier regions of Australia, organisms usually have to evolve special adaptations to cope with drought and heat stress. These include behavioural adaptations such as nocturnal activity and physiological adaptations to minimise water loss. "Many Australian frogs bury themselves in the ground and remain dormant for long periods for this reason," Skeels points out. "Something that is rare in tropical frogs."

The findings are important for the researchers: "They make it clear that we can only understand today's distribution patterns of biodiversity if we include the geological development and climatic conditions of prehistoric times in our considerations," says Pellissier.

The heritage of long past epochs has shaped the patterns of biodiversity right up to the present. It also helps us to understand why more species are found in the tropics today than in temperate latitudes. "To fully understand the distribution of biodiversity and the processes that maintain it in the present, we need to find out how it came about," says the researcher.

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AI reveals hidden traits about our planet's flora to help save species

In a world-first, scientists from UNSW and Botanic Gardens of Sydney, have trained AI to unlock data from millions of plant specimens kept in herbaria around the world, to study and combat the impacts of climate change on flora.

"Herbarium collections are amazing time capsules of plant specimens," says lead author on the study, Associate Professor Will Cornwell. "Each year over 8000 specimens are added to the National Herbarium of New South Wales alone, so it's not possible to go through things manually anymore."

Using a new machine learning algorithm to process over 3000 leaf samples, the team discovered that contrary to frequently observed interspecies patterns, leaf size doesn't increase in warmer climates within a single species.

Published in the American Journal of Botany, this research not only reveals that factors other than climate have a strong effect on leaf size within a plant species, but demonstrates how AI can be used to transform static specimen collections and to quickly and effectively document climate change effects.

Herbarium collections move to the digital world

Herbaria are scientific libraries of plant specimens that have existed since at least the 16th century.

"Historically, a valuable scientific effort was to go out, collect plants, and then keep them in a herbarium. Every record has a time and a place and a collector and a putative species ID," says A/Prof. Cornwell, a researcher at the School of BEES and a member of UNSW Data Science Hub.

A couple of years ago, to help facilitate scientific collaboration, there was a movement to transfer these collections online.

"The herbarium collections were locked in small boxes in particular places, but the world is very digital now. So to get the information about all of the incredible specimens to the scientists who are now scattered across the world, there was an effort to scan the specimens to produce high resolution digital copies of them."

The largest herbarium imaging project was undertaken at the Botanic Gardens of Sydney when over 1 million plant specimens at the National Herbarium of New South Wales were transformed into high-resolution digital images.

"The digitisation project took over two years and shortly after completion, one of the researchers -- Dr Jason Bragg -- contacted me from the Botanic Gardens of Sydney. He wanted to see how we could incorporate machine learning with some of these high-resolution digital images of the Herbarium specimens."

"I was excited to work with A/Prof. Cornwell in developing models to detect leaves in the plant images, and to then use those big datasets to study relationships between leaf size and climate," says Dr Bragg.

"Computer vision" measures leaf sizes

Together with Dr Bragg at the Botanic Gardens of Sydney and UNSW Honours student Brendan Wilde, A/Prof. Cornwell created an algorithm that could be automated to detect and measure the size of leaves of scanned herbarium samples for two plant genera -- Syzygium (generally known as lillipillies, brush cherries or satinas) and Ficus (a genus of about 850 species of woody trees, shrubs and vines).

"This is a type of AI is called a convolutional neural network, also known as Computer Vision," says A/Prof. Cornwell. The process essentially teaches the AI to see and identify the components of a plant in the same way a human would.

"We had to build a training data set to teach the computer, this is a leaf, this is a stem, this is a flower," says A/Prof. Cornwell. "So we basically taught the computer to locate the leaves and then measure the size of them.

"Measuring the size of leaves is not novel, because lots of people have done this. But the speed with which these specimens can be processed and their individual characteristics can be logged is a new development."

A break in frequently observed patterns

A general rule of thumb in the botanical world is that in wetter climates, like tropical rainforests, the leaves of plants are bigger compared to drier climates, such as deserts.

"And that's a very consistent pattern that we see in leaves between species all across the globe," says A/Prof. Cornwell. "The first test we did was to see if we could reconstruct that relationship from the machine learned data, which we could. But the second question was, because we now have so much more data than we had before, do we see the same thing within species?"

The machine learning algorithm was developed, validated, and applied to analyse the relationship between leaf size and climate within and among species for Syzygium and Ficus plants.

The results from this test were surprising -- the team discovered that while this pattern can be seen between different plant species, the same correlation isn't seen within a single species across the globe, likely because a different process, known as gene flow, is operating within species. That process weakens plant adaptation on a local scale and could be preventing the leaf size-climate relationship from developing within species.

Using AI to predict future climate change responses

The machine learning approach used here to detect and measure leaves, though not pixel perfect, provided levels of accuracy suitable for examining links between leaf traits and climate.

"But because the world is changing quite fast, and there is so much data, these kinds of machine learning methods can be used to effectively document climate change effects," says A/Prof. Cornwell.

Read more at Science Daily

Genomes of 233 primate species sequenced

Researchers from 24 countries have analyzed the genomes of 809 individuals from 233 primate species, generating the most complete catalog of genomic information about our closest relatives to date. The project, which consists of a series of studies in which researchers from the German Primate Center -- Leibniz Institute for Primate Research (DPZ) were also involved, provides new insights into the evolution of primates, including humans, and their diversity. In baboons, for example, hybridization and gene flow between different species occurred in the past and is still ongoing in several regions of their range. This makes baboons a good model for the evolution of early human lineages within and outside Africa. In addition, using a specially designed AI algorithm, the genomic data enable new insights into the genetic causes of human diseases (Science, Special Issue).

Primates show great genetic diversity that varies between species and geographic regions. "Studying this diversity is crucial also for understanding human evolution, the causes of human diseases, and for preserving our closest relatives," says Christian Roos, a scientist in the Primate Genetics Laboratory at the German Primate Center and one of the authors. Led by researchers from Universitat Pompeu Fabra, Spain, Baylor College of Medicine, USA, and Illumina Inc, USA, the genomes of 809 individuals from 233 primate species have been sequenced. This covers nearly half of the extant primate species and increases the number of available primate genomes fourfold.

New insights into primate evolution and the uniqueness of humans

The comparative analyses provide fundamental information on the genetic diversity and evolutionary history of primates and important insights into what distinguishes humans from other primates. The genomic data have halved the number of genomic variants thought to occur exclusively in humans. "This makes it easier to look for mutations that we do not share with other primates and that could therefore be the basis for the traits that make us human," says Dietmar Zinner, a scientist in the Cognitive Ethology Laboratory at the German Primate Center and also one of the authors. One of the studies looks more closely at baboon evolution and finds that there have been several, previously unknown episodes of hybridization and gene flow between baboon species. "We found that baboons from western Tanzania are the first nonhuman primates to have received input from three genetic lineages," said Liye Zhang, a doctoral student at the German Primate Center and one of the lead authors of the baboon study. "These results suggest that the genetic structure of the baboon population and its history of genetic exchange between species is more complex than previously thought and show that baboons make a good model for similar processes in the evolution of early human lineages in and outside Africa," says Dietmar Zinner.

Species conservation with the help of genome data

High genetic diversity enables species to better adapt to changing environmental conditions and pathogens. Especially in small populations, there is a risk of inbreeding and thus a reduction in genetic diversity. Already, 63 percent of all primate species are threatened with extinction, and the analysis of genetic diversity provides information which species most urgently need to be protected, at least from a genetic point of view. "We found particularly low genetic diversity in the golden snub-nosed monkey of China and the aye-aye in Madagascar," says Christian Roos.

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Multiple species of semi-aquatic dinosaur may have roamed pre-historic Britain

Palaeontologists at the University of Southampton (UK) studying a British dinosaur tooth have concluded that several distinct groups of spinosaurs -- dinosaurs with fearsome crocodile-like skulls -- inhabited southern England over 100 million years ago.

The team, from the University's EvoPalaeoLab, carried out a series of tests on the 140 million year old tooth, discovered in the early 20th century, in a thick, complicated rock structure named the Wealden Supergroup. The Wealden lies across south-eastern England and was formed around 140-125 million years ago.

The scientists conducted statistical analysis on the tooth, which is stored at the Hastings Museum and Art Gallery in East Sussex. They meticulously compared its characteristics with other species in the spinosaur 'family' of dinosaurs to which it belongs. Their findings, published in the journal PeerJ, confirm the tooth doesn't match that of any identified spinosaur species.

Project supervisor, Dr Neil Gostling explains: "While we can't formally identify a new species from one tooth, we can say this spinosaur tooth doesn't match any of the existing species we know about. Given how many individual teeth exist in collections, this could be just the tip of the iceberg and it's quite possible that Britain may have once teemed with a diverse range of these semi-aquatic, fish-eating dinosaurs."

The Wealden is famous for its spinosaur fossils. Baryonyx -- discovered in Surrey in 1983 -- is one of the world's most significant spinosaur specimens, since it was the first to reveal the true appearance of this crocodile-headed group. Less impressive spinosaur remains -- isolated teeth -- are common throughout the Wealden, and have often been identified as belonging to Baryonyx. However, some experts have long suspected that this is incorrect.

"We used a variety of techniques to identify this specimen, in order to test whether isolated spinosaur teeth could be referred to Baryonyx," said lead author Chris Barker, whose PhD focuses on the spinosaurs of southern Britain. "The tooth did not group with Baryonyx in any of our data runs. It must belong to a different type of spinosaur."

The results show that distinct and distantly related spinosaur types lived in the region during Early Cretaceous times. This backs up research by the EvoPalaeoLab team, who argued in previous studies that the spinosaurs of southern England are more diverse than previously thought.

In 2021, they named the 'Hell Heron' Ceratosuchops from the Isle of Wight, and in 2022 announced the discovery of what might be Europe's largest ever land predator, a giant known only as the 'White Rock' spinosaur. These several spinosaurs did not all live at the same time, but inhabited the region over the course of more than 15 million years.

"Museums themselves are places to make exciting discoveries as our understanding of specimens changes from the time they were deposited," said Dr Neil Gostling. "What this work highlights is the importance of keeping collections alive, and developing our understanding of them. Curators are essential to help us navigate the cupboards and displays, helping us to unpick the often-incomplete records -- either never fully recorded, or lost to time. The diversity of palaeoenvironments is not always hidden in rocks, it is often waiting in a museum, its importance waiting to be rediscovered!"

Read more at Science Daily

Global macrogenetic map of marine habitat-forming species

Species known as marine habitat-forming species -- gorgonians, corals, algae, seaweeds, marine phanerogams, etc. -- are organisms that help generate and structure the underwater landscapes. These are natural refuges for other species, and provide biomass and complexity to the seabeds. But these key species in marine ecosystems are currently threatened by climate change and other perturbations derived from human activity. Now, a study published in the journal Global Ecology and Biogeography warns that even in the marine protected areas (MPAs) the genetic diversity of structural species is not protected, although it is essential for the response and adaptation of populations to changes that alter the natural environment.

The study was carried out by Laura Figuerola-Ferrando, Cristina Linares, Ignasi Montero-Serra and Marta Pagès-Escolà, from the Faculty of Biology of the University of Barcelona and the Biodiversity Research Institute of the UB (IRBio); Jean-Baptiste Ledoux and Aldo Barreiro, from the Interdisciplinary Centre of Marine and Environmental Research (CIIMAR) in Portugal, and Joaquim Garrabou, from the Institute of Marine Sciences (ICM-CSIC).

Genetic diversity is also a component of biodiversity

Traditionally, marine biodiversity management and conservation plans have considered factors such as species richness. Genetic diversity -- another major component of biodiversity -- reflects the genetic variation that exists among organisms of the same species and is a determining factor in the adaptive capacity of populations and their survival. Despite its importance, genetic diversity has so far been overlooked in management and conservation plans.

"Genetic diversity plays a key role in enhancing the ability of species, populations and communities to adapt to rapid environmental changes resulting from climate change and thus increase their resilience," says researcher Laura Figuerola-Ferrando, first author of the study.

"However, -- she continues -- so far, the vast majority of marine protected areas are implemented based on the presence of several species and habitats, without considering their genetic diversity. Another example would be the red list of the International Union for Conservation of Nature (IUCN), which does not consider genetic diversity either."

"In recent years, the need to focus conservation efforts on the protection of genetic diversity has been reinforced. Technological progress in the massive development of different techniques to determine genetic diversity (for example, through the use of microsatellites or small DNA fragments), as well as their affordable cost, can help to include genetic diversity in management and conservation plans," says the researcher from the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB.

From the northwest Atlantic to the Gulf of Guinea

The study applies macrogenetic techniques to identify general genetic patterns of diverse marine species at large spatial scales. The authors have analyzed data from a global database containing genetic diversity information (based on microsatellites) for more than 9,300 populations of 140 species in different marine regions around the globe.

The results outline a reference scenario of genetic patterns in marine habitat-forming species (corals, macroalgae, marine phanerogams, etc.) of potential interest for improving marine life management and conservation plans.

The northwest Atlantic provinces and the Bay of Bengal are the regions where the highest genetic diversity in marine landscape species has been identified. Quite high values (above the global average) have also been identified in the Mediterranean. In contrast, the marine provinces with the lowest values of genetic diversity are the Gulf of Guinea and the southwest Atlantic.

The findings also indicate a positive correlation between genetic diversity and species richness of both animal and plant marine habitat-forming species. However, the paper warns of a worrying result: the Network of Marine Protected Areas (RAMP) in the large oceanic ecoregions does not preserve areas where the genetic diversity of marine habitat-forming species is highest.

"What we have seen is that what is not being protected in MPAs is genetic diversity. In the study, the initial hypothesis was that within these areas there would be greater genetic diversity, but this has not been the case. In fact, we have seen, at a global level, that there are no differences in genetic diversity between inside and outside the MPAs," notes Laura Figuerola-Ferrando, who is doing her doctoral thesis under the supervision of Cristina Linares (UB) and Joaquim Garrabou (ICM-CSIC).

A new pattern of equatorial biodiversity at the poles

The authors have also identified a specific pattern in the distribution of genetic diversity of the marine habitat-forming species that differs from the traditional models known to date. "This is a bimodal latitudinal pattern: it is a complex biogeographic model and it implies that if we model how the genetic diversity of these species varies with latitude, we find two peaks in temperate zones and a small dip in genetic diversity at the equator," notes the ICREA Academia professor Cristina Linares (UB-IRBio), one of the coordinators of the study together with Jean-Baptiste Ledoux (CIIMAR).

This scientific discovery is relevant because until a few decades ago it was considered that the distribution of biodiversity on the planet followed a unimodal pattern, that is, it had maximum values at the equator and decreased towards the poles. "This is not always the case, especially in terms of species diversity in marine ecosystems. For example, in the case of benthic species, this pattern is biomodal rather than unimodal in terms of both species richness and genetic diversity," explains Cristina Linares.

"In our study, the bimodal latitudinal pattern is influenced by taxonomy: in the used model, we found statistically significant differences between animal species (more genetic diversity) and plant species (less genetic diversity). Furthermore, if we explore the latitudinal pattern separating animal and plant species, we can see that a bimodal pattern continues to be observed in animals, but the same cannot be said for plants," adds researcher Jean-Baptiste Ledoux (CIIMAR).

Genetic diversity: improving conservation management plans

The conclusions of the work recall the need to include the genetic diversity of populations in biodiversity management and conservation plans on the planet. "The importance of having genetic diversity in biodiversity management and conservation plans has just been reinforced with the 'Kunming-Montreal Global Biodiversity Framework' within the Convention on Biological Diversity (CBD/COP/15/L25, 2022). In this context, we believe that the baseline on genetic diversity patterns in marine habitat-forming species defined as our work can be very relevant," notes Jean-Baptiste Ledoux.

This study also reveals that the Mediterranean and Atlantic regions are among the most present in the scientific literature used in this work on macrogenetic patterns of deep-sea structural species.

Read more at Science Daily

Humans are unique but not exceptional species of mammal

In modern society, one parent may take a daughter to ballet class and fix dinner so the other parent can get to exercise class before picking up the son from soccer practice. To an observer, they seem to be cooperating in their very busy, co-parenting, monogamous relationship.

These people may think they are part of an evolved society different from the other mammals that inhabit earth. But their day-to-day behavior and child-rearing habits are not much different than other mammals who hunt, forage for food, and rear and teach their children, researchers suggest.

"For a long time it has been argued that humans are an exceptional, egalitarian species compared to other mammals," said Monique Borgerhoff Mulder, professor emerita of anthropology at the University of California, Davis, and corresponding author of a new study. But, she said, this exceptionalism may have been exaggerated.

"Humans appear to resemble mammals that live in monogamous partnerships and to some extent, those classified as cooperative breeders, where breeding individuals have to rely on the help of others to raise their offspring," she said.

The UC Davis-led study, with more than 100 researchers collaborating from several institutions throughout the world, is the first to look at whether human males are more egalitarian than are males among other mammals, focusing on the numbers of offspring they produce.

The article, "Reproductive inequality in humans and other mammals," was published this week (May 22) in the Proceedings of the National Academy of Sciences. Co-authors include researchers from UC Davis, The Santa Fe Institute, the National Institute for Mathematical and Biological Synthesis, and the Max Planck Institute for Evolutionary Anthropology, Germany.

The researchers amassed data from 90 human populations comprising 80,223 individuals from many parts of the world -- both historical and contemporary. They compared the records for men and women to lifetime data for 45 different nonhuman, free-ranging mammals.

The researchers found that humans are by no means exceptional, merely another unique species of mammal. Furthermore, as first author Cody Ross, former UC Davis graduate student in the Department of Anthropology now at the Max Planck Institute, points out "we can quite successfully model reproductive inequality in humans and nonhumans using the same predictors."

Egalitarianism in polygynous societies

Somewhat unexpectedly, when focusing specifically on women, the researchers found greater reproductive egalitarianism in societies that allow for polygynous marriage than in those where monogamous marriage prevails. In polygynous systems, in which men take several wives at the same time, women tend to have more equal access to resources, such as land, food and shelter -- and parenting help. This is because women, or their parents on their behalf, favor polygynous marriages with wealthy men who have more resources to share.

Researchers observed something else in their work.

"It turns out that monogamous mating (and marriage) can drive significant inequalities among women," Borgerhoff Mulder said. Monogamy, practiced in agricultural and market economies, can promote large differences in the number of children couples produce, researchers found, resulting from large differences in wealth in such economies.

How humans may differ

The fact men are relatively egalitarian compared to other animals reflects our patterns of child rearing. Human children are heavily dependent on the care and resources provided by both mothers and fathers -- a factor that is unusual, but not completely absent -- in other mammals, researchers said.

The critical importance of the complementary nature of this care -- that that each parent provides different and often non-substitutable resources and care throughout long human childhoods -- is why we don't show the huge reproductive variability seen in some of the great apes, said researcher Paul Hooper, from the University of New Mexico.

Read more at Science Daily

Climate change to push species over abrupt tipping points

Climate change is likely to abruptly push species over tipping points as their geographic ranges reach unforeseen temperatures, finds a new study led by a UCL researcher.

The new Nature Ecology & Evolution study predicts when and where climate change is likely to expose species across the globe to potentially dangerous temperatures.

The research team from UCL, University of Cape Town, University of Connecticut and University at Buffalo analysed data from over 35,000 species of animals (including mammals, amphibians, reptiles, birds, corals, fish, cephalopods and plankton) and seagrasses from every continent and ocean basin, alongside climate projections running up to 2100.

The researchers investigated when areas within each species’ geographical range will cross a threshold of thermal exposure, defined as the first five consecutive years where temperatures consistently exceed the most extreme monthly temperature experienced by a species across its geographic range over recent history (1850-2014).

Once the thermal exposure threshold is crossed, the animal is not necessarily going to die out, but there is no evidence that it is able to survive the higher temperatures – that is, the research projects that for many species there could be an abrupt loss of habitat due to future climate change.

The researchers found a consistent trend that for many animals, the thermal exposure threshold will be crossed for much of their geographic range within the same decade.

Lead author Dr Alex Pigot (UCL Centre for Biodiversity & Environment Research, UCL Biosciences) said: “It is unlikely that climate change will gradually make environments more difficult for animals to survive in. Instead, for many animals, large swaths of their geographic range are likely to become unfamiliarly hot in a short span of time.

“While some animals may be able to survive these higher temperatures, many other animals will need to move to cooler regions or evolve to adapt, which they likely cannot do in such short timeframes.

“Our findings suggest that once we start to notice that a species is suffering under unfamiliar conditions, there may be very little time before most of its range becomes inhospitable, so it’s important that we identify in advance which species may be at risk in coming decades.”

The researchers found that the extent of global warming makes a big difference: if the planet warms by 1.5°C, 15% of species they studied will be at risk of experiencing unfamiliarly hot temperatures across at least 30% of their existing geographic range in a single decade, but this doubles to 30% of species at 2.5°C of warming.

Dr Pigot added: “Our study is yet another example of why we need to urgently reduce carbon emissions to mitigate the harmful effects climate change is having on animals and plants, and avoid a massive extinction crisis.”

The researchers hope that their study could help with targeting conservation efforts, as their data provides an early warning system showing when and where particular animals are likely to be at risk.

Co-author Dr Christopher Trisos (African Climate and Development Initiative, University of Cape Town) said: “In the past we’ve had snapshots to show the impact of climate change, but here we are presenting the data more like a film, where you can see the changes unfold over time. This shows that for many species the risk is a bit like everything, everywhere, all at once. By animating this process, we hope to help direct conservation efforts before it’s too late, while also showing the potentially catastrophic consequences of letting climate change continue unchecked.”

The researchers say that this pattern of abrupt exposure may be an inevitable feature of living on a round planet – because of the shape of the Earth, there is more area available to species in environments near the hot end of what they are used to, such as in low-lying areas or near the equator.

A previous study by the same lead authors found that even if we stop climate change so that global temperatures peak and start to decline, the risks to biodiversity could persist for decades after. In another analysis similar to the current study, they found that many species facing unfamiliar temperatures will be living alongside other animals experiencing similar temperature shocks, which could pose grave risks to local ecosystem function.

Read more at Science Daily

A jumping conclusion: Fossil insect ID'd as new genus, species of prodigious leaper, the froghopper

A fossil arthropod entombed in 100-million-year-old Burmese amber has been identified as a new genus and species of froghopper, known today as an insect with prodigious leaping ability in adulthood following a nymphal stage spent covered in a frothy fluid.

Oregon State University researcher George Poinar Jr., an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past, and his co-author, Alex E. Brown, published the findings in the journal Life.

The authors categorized the new froghopper as Araeoanasillus leptosomus, from the Greek words for thin (araeos) and bristling hair (anasillos) in reference to fern hairs (trichomes) associated with the specimen.

The froghopper superfamily, Cercopoidea, contains five families that exist today -- Cercopoidae, Aphrophoridae, Clastopteridae, Epipygidae and Machaerotidae -- as well as the extinct families Cercopionidae, Procercopidae and Sinoalidae.

"Based on its diagnostic characteristics, our specimen seems to fall in the family Sinoalidae," Poinar said.

Froghoppers are in the order Hemiptera. Known as "true bugs," the Hemiptera order is made up of more than 80,000 species including cicadas, aphids, planthoppers, leafhoppers, bed bugs and shield bugs.

True bugs' size varies widely, from as small as 1 millimeter to as large as 15 centimeters, but they all, except for some of the smaller males, have a similar arrangement of sucking mouthparts, Poinar said.

In its "spittlebug" form, an immature froghopper taps into a plant stem's sap, sucks it in and then releases it from its rectum, the researcher explained. The spittlebug froths the extruded fluid -- think cappuccino maker -- and covers itself with the resulting slippery foam, which conceals it from predators like ants and also protects it from the parasitic wasps that like to lay eggs inside the spittlebug's body.

In adulthood these small (generally around 1 centimeter long), brown bugs can spring forward up to 100 times their body length thanks to their powerful hind legs equipped with structures that flex like an archery bow and can exert force 400 times greater than their body weight.

Froghoppers feed on many types of plants and are found anywhere vegetation grows, Poinar added. They hold their wings together like a tent over their body and can fly but generally prefer to get around by leaping.

The newly identified extinct froghopper has a slender, 7-millimeter-long body with a head that's longer than it is wide and eyes that are broad and round. There are fern hairs (trichomes) on and adjacent to the specimen, suggesting that it fed and laid eggs on ferns, Poinar said.

"This is understandable since flowering plants were only beginning to diversify at that period in the mid-Cretaceous and ferns were very abundant," said Poinar, who also recently described a new genus of ferns in Burmese amber. "Beyond that, we don't know much about the biology of extinct froghoppers -- food preferences, feeding habits, parasites, or even whether the nymphs were able to produce froth.

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For birds, blending in may result in more diversity

The saying "Birds of a feather flock together" is being given new meaning by a study published in the Philosophical Transactions of the Royal Society b. Flocking birds often travel in groups made up of a single species, in which individuals are nearly indistinguishable from one another, as noted by the proverbial adage. But something strange happens in flocks of two or more species from Southeast Asia. Even when flock species are distantly related, they still seem to converge on the same appearance, as if trying to fit in.

"They all share haphazard traits, like crests or yellow bellies, which makes them almost identical. You can't really tell them apart without looking at their markings," said study co-author Scott Robinson, Ordway eminent scholar at the Florida Museum of Natural History.

According to Robinson, this similarity in plumage is likely a type of mimicry, which by itself isn't uncommon in birds. Alfred Russel Wallace, the co-discoverer of natural selection, was the first to suggest that some bird species engage in mimicry when noting the similarities between orioles and friarbirds in Australia. Birds can mimic one another to reduce aggression from a dominant species; to resemble a more formidable adversary to predators; and, in at least one case, to make themselves appear toxic.

But resemblance in multispecies flocks is something different, said lead author Rebecca Kimball, professor of biology at the University of Florida.

"In mimicry, you often want to look like something because there's an advantage to being that other thing. You want species to think you're toxic or low-profitable prey," she said. "In flocking birds, one idea is that this has more to do with a predator's ability to isolate a target. When there are a bunch of birds moving around, it may be easier for predators to identify an individual that has a distinct color pattern."

This idea that unrelated birds find safety in collective obscurity was first proposed in the 1960s for flocks along the Andes Mountains. But follow-up studies failed to show conclusive evidence of mimicry in Andean multispecies flocks, and the theory was largely abandoned.

"The idea sat fallow for a long time," Robinson said. But in 2010, Robinson began working with a Chinese colleague in Yunnan province and observed what appeared to be the same phenomenon that had been described decades earlier.

Robinson and his colleagues spent the next several years documenting similarities in China's multispecies flocks, uncovering the same pattern again and again. While some of the similarities between species are subtle, the authors points to several visually conspicuous examples.

In western Asia, Himalayan cutias (Cutia nipalensis) look like they're dressed in mismatched layers, with a mask of black feathers, chestnut wings, and white chests with zebra stripes. This pattern might seem impervious to emulation, yet the rufous-backed sibias (Leioptila annectens) they flock with do a remarkably good impression. Both species have similar behavior, foraging patterns and markings, with the exception of stripes, which the sibias lack.

Some birds also seem capable of mimicking more than one species as they mature. Juvenile white-hooded babblers (Gampsorhynchus rufulus) have rusty head feathers, brown wings and creamy underbellies, similar to the parrotbills they flock with. Adults look like an entirely different species, with white heads and dark brown wings that resemble white-crested laughingthrushes (Garrulax leucolophus), all of which are part of the same flock.

Somewhat counterintuitively, this conformity within multispecies flocks may be contributing to diversity in the region. Not only can birds mimic more than one species at different stages of development, but their appearance can also vary across their range. In eastern China, coal tits tag along with birds with prominent crest feathers, which they mimic. In the Himalayas and Hengduan Mountains farther west, the same species lacks a crest and flocks with other crestless birds.

If these differences persist long enough, Robinson said, it might ultimately result in one species becoming two. "The possible role this type of mimicry plays in speciation is the most interesting idea from our point of view. Many of these birds have huge ranges, and there may be a lot of differentiation in these traits involved in flocking within a species."

There seem to be two main ingredients required to create this type of mimicry in flocks, both of which might help explain why this pattern appears to be so prominent in China but absent elsewhere.

First, Robinson said, a flock must be composed of just a few species, with some more common than others. "When you have a flock with a really dominant, abundant species, there's a model worth mimicking. If other birds look like that model, they get the same protection, they get access to the same resources, and they get to travel with a compatible group."

In other parts of the world, many flocks have more of an open-door policy, weakening the selective forces that contribute to mimicry. Mating pairs of multiple species join together in patchwork groups, often relying on the warning calls of sentries to avoid predators rather than their ability to fade into the background.

The second ingredient is the winnowing fan of predation. For small to medium flocking birds, the biggest source of danger comes from above, in the form of raptors, and the skies above Southeast Asia are especially fraught. The region encompasses only 3% of Earth's land area, yet it harbors almost 30% of all raptor species. This puts an enormous amount of pressure on flocks, Robinson said, which may promote mimicry.

To determine whether similarity among flocking species is the result of mimicry, the authors say they'll need to conduct widescale genetic analyses to rule out other potential causes.

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Family tree of 'boring' butterflies reveals they're anything but

Walk a short distance through the Amazon Rainforest, and you might witness what look like dead leaves launch from the ground and fly off into the understory. These masters of disguise are euptychiines, one of the most diverse and least understood groups of butterflies in the American Tropics.

There are as many as 100 co-occurring euptychiine species in the rainforests of Peru and Brazil, but even the most seasoned butterfly experts have a hard time telling them apart.

"They're one of the groups that often get called 'brown, boring butterflies,'" said André Freitas, a biology professor at the State University of Campinas in Brazil. "They aren't very attractive to collectors or researchers, and even distantly related species can look very similar. The early naturalists had no way to accurately classify them."

Freitas is a co-author on a new study that adds some much-needed definition to what has remained, up until now, a black hole of butterfly diversity. The German entomologist Jacob Hübner was the first to describe the group in the early 1800s, when he lumped the few species then known into a handful genera based on similar appearance.

Using DNA, Freitas and his colleagues show there are at least 70 Euptychiina genera, containing more than 500 species. Their results also suggest there are at least 130 unnamed species in the group awaiting scientific description.

The study is the result of a project more than a decade in the making, initially conceived by Keith Willmott, director of the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History. In 2009, Willmott reached out to Freitas and other researchers who'd taken a stab at individually sorting through euptychiine butterflies piecemeal and proposed they instead combine their efforts.

Before researchers could make heads or tails of euptychiine diversity, they first needed a sense of just how many groups there were and how they were related to each other.

"The way people would typically work on this kind of problem would be to divide and conquer, but that doesn't work for euptychiines, because there are very few unifying features among species that you can use to define groups," Willmott said.

Instead, a coalition of international researchers focused on studying as many euptychiine species as they could lay their hands on. They examined more than 60,000 specimens from museums in Europe and North and South America and collected euptychiine butterflies throughout their range, from the foothills of the Andes in Ecuador to the Atlantic Forest in Southeastern Brazil.

In the process, they discovered more than 100 new species, many of which were hiding in plain sight, concealed by their close resemblance to each other.

"A recent example is a large butterfly that used to be known as Pseudodebis celia from western Ecuador, which turned out to be four separate species," Willmott said. "These are big butterflies. It's hard to imagine these kinds of species are still escaping detection."

Not all euptychiines have evolved to blend in. Several species have bright blue scales or blazing orange eyespots, which might seem like it'd make them easy to classify. But closer inspection reveals these color patterns can be deceptive as well. Results of the study's genetic analysis show, for example, that multiple, Euptychiines have transformed their wings into blue frescoes, making them appear superficially similar.

Mimicry is often the primary suspect when unrelated butterflies have a similar appearance. Predators learn to avoid species with toxic, bitter-tasting compounds, like Monarchs (Danaus plexippus). With a little false advertising, species that lack these compounds can still deter predators by copying the colors and patterns of genuinely toxic butterflies.

But according to Willmott, this likely isn't the case for euptychiines. "As far as we know, they're not unpalatable or protected against predators in any way. It looks like mimicry, but there's really no basis for it. It's a fascinating mystery that needs study."

Blue euptychiines can play further tricks on butterfly experts -- sometimes, the color is only present in some individuals of a given species.

"In most cases, the males are colorful, and the females are brown," said Marianne Espelend, a curator at the Leibniz Institute for the Analysis of Biodiversity and lead author on the study.

This mismatch has led to several cases of mistaken identity. A brown species from French Guiana described in 2012 was later determined to be the incognito female half of a well-known species discovered a century earlier. This triggered inspection of other blue species, and discovery of similar problems.

The new classification provided by this study will help researchers pin down the exact identity of familiar euptychiines and shorten the long queue of species in the group that have yet to be given a scientific name.

It also sets the stage for scientific forays into other aspects of euptychiine biology that experts are just now beginning to understand, said Freitas, reciting a litany of unknowns that can now be thoroughly investigated.

"We know that several species have scales that release scents to attract females, but we have no idea what types of chemicals are involved; the males of some species make an audible clicking sound, but we don't know how they do it; and I can count on my hand the number of times I've been able to find euptychiine caterpillars in the wild, of which we know very little."

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Climate: Lessons from the latest global warming

56 million years ago, the Earth experienced one of the largest and most rapid climate warming events in its history: the Paleocene-Eocene Thermal Maximum (PETM), which has similarities to current and future warming. This episode saw global temperatures rise by 5-8°C. It was marked by an increase in the seasonality of rainfalls, which led to the movement of large quantities of clay into the ocean, making it uninhabitable for certain living species. This scenario could be repeated today. This is what a team from the University of Geneva (UNIGE) has revealed, thanks to the analysis of sediments taken from the deep waters of the Gulf of Mexico. These results can be found in the journal Geology.

The Paleocene-Eocene Thermal Maximum (PETM), which occurred 56 million years ago, is the largest and most rapid climatic disturbance of the Cenozoic era (65.5 million years ago to the present day). Exceptional both in terms of its amplitude (5-8°C increase) and its suddenness (5,000 years, a very short time on a geological scale), this episode was marked by a warming of temperatures on a global scale. It lasted for about 200 000 years and led to numerous marine and terrestrial extinctions.

It would have been caused by a high concentration of carbon dioxide -- the famous CO2 -- and methane in the atmosphere, two powerful greenhouse gases. As is the case currently, these gases may have been released by several phenomena, certainly in combination: the release of methane hydrates trapped on the seabed, the sudden and significant melting of the permafrost, and the injection of magma into the organic sediments of the western edge of Norway. The origin of these processes is still under debate. The impact of a meteorite and/or the effects of intense volcanic activity in the depths of the North Atlantic could be responsible.

A geological ''archive'' of unprecedented quality

Because of the many similarities between the PETM and the current warming, the geological remains of this period are being closely studied by scientists. A team from the UNIGE is now reporting new elements. ''The objective of our study was to investigate the influence of these climatic changes on sedimentary systems, i.e. on the processes of sediment formation and deposition, and to understand how these changes could have been transmitted from the atmosphere to the depths of the ocean,'' explains Lucas Vimpere, a post-doctoral scholar at the Section of Earth and Environmental Sciences of the UNIGE's Faculty of Science and first author of the study.

The researchers analysed sediments taken from more than 8km deep in the Gulf of Mexico. This basin acts as a giant ''sink'' into which material eroded and transported from the North American continent over millions of years is discharged. ''For reasons of cost and infrastructure, the sediments used to study the PETM are generally taken from shallow marine or continental environments. Thanks to the collaboration of an oil company, we were able to obtain a sample of unprecedented quality, without any alteration'', says the researcher. The 543-metre-long core contains a 180-metre-thick PETM sedimentary record, making it the most complete geological ''archive'' of this period in the world.

More clay on the ocean floor

The UNIGE scientists found that it was composed first of a large layer of clay and then of a layer of sand, a counter-intuitive result. ''At the time of the PETM, we thought that there had been more precipitation, and therefore more erosion, and that large quantities of sand had then been transported first by the fluvial systems into the oceans. However, thanks to our sample, we were able to determine that it was the clays and not the sands that were transported in the first instance'', explains Sébastien Castelltort, full professor at the Earth and Environmental Sciences Section of the UNIGE Faculty of Science, and last author of the study.

This established that the period was not marked by an increase in the annual rate of precipitation but by an increase in its seasonality and intensity. ''This resulted in increased mobility of the river channels -- the deepest areas of a river -- which in turn transported large quantities of fluvial clays deposited on the adjacent alluvial plains to the ocean depths. We can now consider the presence of clay in deep basins as a marker of increased rainfall seasonality,'' says Lucas Vimpere. The phenomenon has led to an increase in ocean turbidity that is harmful to marine life, especially corals.

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