Rainfall and ocean circulation linked in past and present

Kaustubh Thirumalai (Brown University) helping retrieve a CTD instrument, which collects water samples and measures physical parameters of oceanic waters such as temperature, aboard the R/V Point Sur in the northern Gulf of Mexico.

Research conducted at The University of Texas at Austin has found that changes in ocean currents in the Atlantic Ocean influence rainfall in the Western Hemisphere, and that these two systems have been linked for thousands of years.

The findings, published on Jan. 26 in Nature Communications, are important because the detailed look into Earth's past climate and the factors that influenced it could help scientists understand how these same factors may influence our climate today and in the future.

"The mechanisms that seem to be driving this correlation [in the past] are the same that are at play in modern data as well," said lead author Kaustubh Thirumalai, postdoctoral researcher at Brown University who conducted the research while earning his Ph.D. at the UT Austin Jackson School of Geosciences. "The Atlantic Ocean surface circulation, and however that changes, has implications for how the rainfall changes on continents."

Thirumalai conducted the work at The University of Texas Institute for Geophysics (UTIG), a research unit at the UT Jackson School of Geosciences. Co-authors include UTIG scientists, and researchers from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center and the Massachusetts Institute of Technology.

The Atlantic Ocean surface circulation is an important part of the Earth's global climate, moving warm water from the tropics towards the poles. The foundation of the research involved tracking the changes in ocean circulation in new detail by studying three sediment cores extracted from the seafloor of the Gulf of Mexico in 2010 during a scientific cruise. The samples give insight into factors that influenced the strength of the ocean current in about 30-year increments over the past 4,400 years.

"If we go back in increments of 30, we're well positioned to understand things on the order of centuries," Thirumalai said. "And the question we decided to ask was what can those reconstructions of temperature and salinity tell us about the greater Atlantic Ocean surface circulation."

The small time increments scientists were able to capture in the cores are due to the large amounts of sediment that empty into the Gulf from rivers in Mexico and North America. The scientists extracted data about temperature and salinity data -- factors that influence ocean current strength -- from ocean-dwelling microorganisms called foraminifera preserved in the sediments.

The data showed that, in comparison to today, the Atlantic Ocean surface circulation was much weaker during the Little Ice Age, a cool period thought to be triggered by volcanic activity that lasted from 1450-1850. Since these set of ocean currents are known to influence global climate, the researchers were interested to see if it correlated with rainfall in the Western Hemisphere, and how such a correlation could change over time.

To calculate the correlation during the Little Ice Age, researchers compared the core data with proxies for precipitation data, such as data from tree rings, cave formations and other natural records. And to calculate the modern correlation, they compared data collected by humans during the last century on the temperature and salinity of the Gulf and rainfall in the Western Hemisphere. They also analyzed data from a climate model developed by the Max-Planck Institute for Meteorology in Germany to predict what the correlation between the current and rainfall would be expected to be during the Little Ice Age.

The results indicate that in present and past the Atlantic Ocean surface currents correlate with rainfall patterns in the Western Hemisphere. Thirumalai said that this finding is important for two reasons. It shows that a correlation exists between the current and rainfall patterns, and that the correlation is evident in data sets that cover different time scales.

"It was remarkable," Thirumalai said. "These patterns that are based on decadal analysis of modern data, and then the hydroclimate proxies that give the salinity in the oceans and the rainfall on land seem to show the same picture."

The findings emphasize the importance of the Atlantic Ocean surface circulation to rainfall, and that changes in the current can have far reaching impacts. That means that future changes to the Gulf's salinity and temperature could be expected to influence the climate in other ways.

"The study demonstrates a robust century-scale link between ocean circulation changes in the Atlantic basin and rainfall in the adjacent continents during the past 4,000 years," said UTIG Director Terry Quinn, a co-author on the study. "And hence it provides a baseline for predictions on how that part of the climate system may behave in the future."

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From stem cells to a functional heart: The role of the Mesp1 gene

This is a mosaically labeled embryonic heart. Each colored patch is derived from the early labeling of a cardiac progenitor cell expressing the key gene Mesp1.

Researchers at the Université libre de Bruxelles and University of Cambridge identified the role of key gene Mesp1 in the earliest step of cardiovascular lineage segregation. This discovery may help to better understand congenital heart defects.

The heart is the first organ that forms during development and contains four different regions (ventricles and atria), which contain different cells that perform specialized functions: the beating cardiomyocytes ensure the pumping activity, vascular cells represent the inner lining and blood vessels and the pacemaker cells set the heartbeat. Unless the progenitor cells that will form the heart are specified at the correct time, migrate to the correct location, and differentiate into the correct cell types, severe malformations of the heart occur. In human patients, these are recognized as congenital heart diseases, which represent the most common cause of severe birth defects in newborne babies. Previous studies had shown that a diverse range of heart progenitor cells arises from different pools of cells expressing the Mesp1 gene. However, it remained unclear how the various progenitors can be distinguished at the molecular level, and what molecular mechanisms promote specification into a particular heart region or cardiac lineage.

In a new study published in early release of Science, researchers led by Pr. Cédric Blanpain, Laboratory of Stem Cells and Cancer, Université libre de Bruxelles, Belgium, and Pr. Berthold Göttgens, the Universtity of Cambridge, identified the role of Mesp1 in the earliest step of cardiovascular lineage segregation by single cell molecular profiling and lineage tracking.

Fabienne Lescroart and colleagues isolated Mesp1 expressing cells at different stages of embryonic development and performed single cell transcriptomic analysis of these early cardiac progenitors to identify the molecular features associated with regional and cell type identity of cardiac progenitors. They demonstrated that the different populations of cardiac progenitors are molecularly distinct.

To determine the role of the transcription factor Mesp1 in regulating the cardiovascular differentiation program and the heterogeneity of early cardiovascular progenitors, they also performed single cell molecular profiling of these early progenitors in a Mesp1 deficient context. These experiments showed that Mesp1 is required for the exit from the pluripotent state and the induction of the cardiovascular gene expression program.

Bioinformatic analysis identified, among these early Mesp1 progenitors, distinct populations of cells corresponding to progenitors committed to different cell lineages and regions of the heart, identifying the molecular features associated with early lineage restriction and regional segregation of the heart. While progenitor cells are not yet differentiated, this new analysis shows that cardiovascular progenitors are already "primed" or pre-specified to give rise to cardiac muscle cells or vascular cells. The researchers found that these different populations are also born at different time points and are located at specific locations at this early stage of development. Finally, the researchers have identified the earliest branching point between the cardiac and vascular lineages, and shown that Notch1 marks the early progenitor committed to the vascular lineage during early embryonic development.

Understanding the molecular features associated with early cardiovascular lineage commitment and heart regions will be important to design new strategies to instruct cardiovascular progenitors to adopt cardiac or vascular identity from different heart regions that can be used for cellular therapy of cardiac diseases. " Future studies will be required to determine whether the paradigm of early lineage segregation identified here controls the formation of the different lineages in different organs and tissues. It will also be important to determine whether the molecular features uncovered here play a role in congenital cardiac malformations and can be used to push cardiovascular progenitors into a particular lineage, which can have important implications for improving cell therapy for cardiac repair" comments Pr Cédric Blanpain, one of the senior authors of this study.

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Humans take up too much space -- and it's affecting how mammals move

One of the lions in Tsavo, Kenya, whose movements were tracked for this study.

Human beings take up a lot of real estate -- around 50-70 percent of the Earth's land surface. And our increasing footprint affects how mammals of all sizes, from all over the planet, move.

A study recently published by Science found that, on average, mammals living in human-modified habitats move two to three times less far than their counterparts in areas untouched by humans. What's more, this pattern persists globally: from African forest elephants to white-tailed antelope squirrels in North America, the human footprint infringes upon the footprints of mammal species both big and small. The study, led by Marlee Tucker of the Senckenberg Biodiversity and Climate Research Centre in Germany, is the first of its kind to log movement behaviors for such a wide range of mammals globally.

"All organisms need space," Bruce Patterson, a co-author of this study and MacArthur Curator of Mammals at The Field Museum in Chicago, explained. "They need space to gather their resources, find mates, and perform their ecological services." For instance, bats need room to find and consume insects and pollinate plants (which amount to $3.5 to 50 billion worth of agricultural labor annually in the US alone), and apex predators need room to hunt and control other species' populations.

In the study, more than 100 researchers contributed information on 803 individual mammals representing 57 species in total. Patterson offered up data on the movement of lions in a pristine wilderness area of Tsavo, Kenya. From 2002-09, he followed three lions using high-tech collars that continuously tracked individuals' movement via GPS -- the data he contributed to the Science study. One of those lions, in its natural habitat, patrolled an area twice the size of Chicago (1400 km2) to find food, attract mates, and repel intruders.

But habitat loss and fragmentation disrupt these critical animal behaviors. Clearing rainforest is an example of habitat loss -- the destruction and loss of usable area for a given species. Constructing a road through the savannah, on the other hand, constitutes habitat fragmentation -- the division of habitat area into smaller, discontinuous spaces. When suitable habitat spaces become too small or too isolated, animals can no longer afford to visit them, changing their space use.

As habitats become compromised, resources like food and living space that animals rely on become scarce. Sometimes, when resources are limited, animals traverse larger areas to get what they need -- if there's not enough food in a five-mile radius, they might move to a ten-mile radius. However, this study shows that on the whole, that sort of additional movement tends not to be an option -- if there's no uninterrupted landscape available, then the affected animals simply can't live there.

To that end, the Science study found "strong negative effects of the human footprint on median and long-distance displacements of terrestrial mammals." Patterson put it more simply: "Human dominion over Earth's landscapes gets in the way of animals doing their thing." Some species, like mice, can make do with less room, but animals that need lots of space, like lions, tigers, and elephants, simply can't live in areas with lots of humans.

"It is important that animals move, because in moving they carry out important ecological functions like transporting nutrients and seeds between different areas. Additionally, mammalian movements bring different species together and thus allow for interactions in food webs that might otherwise not occur. If mammals move less this could alter any of these ecosystem functions," says lead author Marlee Tucker.

Across the wide array of species its data encompasses, the study points to a singular, and grim, conclusion: For mammal species, the effects of habitat loss and habitat fragmentation don't discriminate by geographic location, body size, or where that species sits on the food chain -- the human footprint threatens most other mammals.

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Paleontology: The eleventh Archaeopteryx

The geologically oldest, but most recently discovered specimen of Archaeopteryx.

Researchers from Ludwig-Maximilians-Universitaet (LMU) in Munich report the first description of the geologically oldest fossil securely attributable to the genus Archaeopteryx, and provide a new diagnostic key for differentiating bird-like dinosaurs from their closest relatives.

Some 150 million years ago in what is now Northern Bavaria, Archaeopteryx -- the oldest bird species yet discovered -- inhabited a subtropical environment characterized by reef islands and lagoons set in a shallow sea that was part of the primordial Mediterranean. All the specimens of Archaeopteryx so far recovered were found in the valley of the Altmühl River, in geological settings that represent this habitat -- the Jurassic Solnhofen Archipelago. The latest find was made there in 2010, and this new specimen has now been analyzed by a team of researchers led by LMU paleontologist Oliver Rauhut, a professor in the Department of Earth and Environmental Sciences who is also affiliated with the Bavarian State Collections for Paleontology and Geology in Munich. Stratigraphic analysis of the find locality reveals that the fossil is the oldest known representative of the genus Archaeopteryx.

"Specimens of Archaeopteryx are now known from three distinct rock units, which together cover a period of approximately 1 million years," Rauhut explains. Notably, the oldest example exhibits features that were so far not known from the other specimens. "Among other things, they reveal that Archaeopteryx was very similar to advanced predatory dinosaurs in many respects," says Rauhut. Moreover, in the new study, he and his colleagues provide a diagnosis that allows to reliably distinguish Archaeopteryx from its closest relatives, both non-avialan theropod dinosaurs and basal birds. This key will be very valuable, as a whole series of bird-like predatory dinosaurs has been described in recent years, mainly from China, which has greatly complicated the taxonomical classification of the group.

The new specimen is the 12th fossil to be attributed to the genus. However, in a study published in the online journal BMC Evolutionary Biology last year, Rauhut's group reported that the first of these to come to light -- the so-called Haarlem specimen discovered in 1861 -- does not actually belong to the group. This result thus reduces the number of Archaeopteryx fossils to 11, although some doubts remain concerning the assignment of two of these. This underlines the necessity for a diagnosis to clearly identify Archaeopteryx.

Moreover, the investigation of the 11th specimen demonstrates that the known specimens span a remarkable range of anatomical variation. Potential explanations for the broad spectrum of variation extend from intraspecific developmental polymorphism to evolutionary differentiation, i.e., the possibility that the fossil material so far recovered represents more than one species. "The high degree of variation in the teeth is particularly striking -- none of the specimens shows the same pattern of dentition as any other, which could reflect differences in diet," Rauhut points out. "This is very reminiscent of the famous case of Darwin's finks on the Galapagos, which show remarkable variation in their beak shapes. It is even conceivable that this primeval bird genus might, in a similar fashion, have diversified into several specialized forms on the islands of the Solnhofener Archipelago. In that case, the Archaeopteryx fossils could represent a species flock, a Jurassic analog of Darwin's finches."

From Science Daily

Archaeologists say they may have discovered one of the earliest examples of a 'crayon'

The crayon revealed a sharpened end.

Archaeologists say they may have discovered one of the earliest examples of a 'crayon' -- possibly used by our ancestors 10,000 years ago for applying colour to their animal skins or for artwork.

The ochre crayon was discovered near an ancient lake, now blanketed in peat, near Scarborough, North Yorkshire. An ochre pebble was found at another site on the opposite side of the lake.

The pebble had a heavily striated surface that is likely to have been scraped to produce a red pigment powder. The crayon measures 22mm long and 7mm wide.

Ochre is an important mineral pigment used by prehistoric hunter-gatherers across the globe. The latest finds suggest people collected ochre and processed it in different ways during the Mesolithic period.

The ochre objects were studied as part of an interdisciplinary collaboration between the Departments of Archaeology and Physics at the University of York, using state-of-the-art techniques to establish their composition.

The artefacts were found at Seamer Carr and Flixton School House. Both sites are situated in a landscape rich in prehistory, including one of the most famous Mesolithic sites in Europe, Star Carr.

A pendant was discovered at Star Carr in 2015 and is the earliest known Mesolithic art in Britain. Here, more than 30 red deer antler headdresses were found which may have been used as a disguise in hunting, or during ritual performances by shamans when communicating with animal spirits.

Lead author, Dr Andy Needham from the University of York's Department of Archaeology, said the latest discoveries helped further our understanding of Mesolithic life.

He commented: "Colour was a very significant part of hunter-gatherer life and ochre gives you a very vibrant red colour. It is very important in the Mesolithic period and seems to be used in a number of ways.

"One of the latest objects we have found looks exactly like a crayon; the tip is faceted and has gone from a rounded end to a really sharpened end, suggesting it has been used.

"For me it is a very significant object and helps us build a bigger picture of what life was like in the area; it suggests it would have been a very colourful place."

The research team say Flixton was a key location in the Mesolithic period and the two objects help paint a vibrant picture of how the people interacted with the local environment.

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Greenpeace Submarine Catalogs Life on Antarctica’s Seafloor

TA two person submarine at the surface after a dive, next to Greenpeace ship the Arctic Sunrise at Livingston Island, Antarctica. Greenpeace is conducting submarine-based scientific research to strengthen the proposal to create the largest protected area on the planet, an Antarctic Ocean Sanctuary.

Deep beneath the frigid oceans off Antarctica lies a haven for marine life adapted to one of the most hostile places on Earth.

Researchers from Greenpeace recently dove to the seafloor off the Antarctic peninsula in a small submarine and cataloged a rich variety of species in an area the environmental organization hopes to see protected.

“It really looks like a garden, although it’s all animals,” Greenpeace marine biologist John Hocevar told Seeker. “It’s too deep for light to penetrate, so there are no plants. But we’re seeing really dense assemblages of sponges, corals, sea squirts, bryozoans, and all kinds of relatives of sea stars.”

At more than 1,000 feet (305 meters) below the surface, the population is mostly invertebrates. The water temperature is too cold for most fish, Hocevar said. The surrounding ocean is about 1 degree below zero Celsius (30 degrees Fahrenheit), kept from freezing by the salt in the water.

The fish that do survive in the waters carry a protein in their blood that serves as a kind of natural antifreeze. The Greenpeace expedition spotted a few, including a species of crocodile icefish that researchers are still trying to identify, since few have been cataloged alive.

“You try to identify it at the species level from existing images, and they’re nearly all from specimens collected in trawls or on hooks,” Hocevar said. “Comparing this fish in its natural habitat to something that’s dead and desiccated is a little bit more challenging than I would have thought. Even the experts on some of these species have never seen one alive.”

The Antarctic feather star, Promachocrinus kerguelensis, found at approximately 300 meters depth at Kinnes Cove, Antarctic Sound found at approximately 300 meters depth at Kinnes Cove in the Antarctic Sound. Greenpeace is conducting submarine-based scientific research to strengthen the proposal to create the largest protected area on the planet, an Antarctic Ocean Sanctuary.

Image of the Antarctic seafloor

The two-person, battery-driven submarine is lowered over the side of the Greenpeace ship Arctic Sunrise. It’s about the size of a small car, and cramped: “If you turn your head, you might knock something over,” Hocevar said.

The expedition was aimed at building evidence to support the establishment of a protected marine reserve off Antarctica by an international body that oversees commercial fisheries in the high Southern latitudes. That group, the Commission for the Conservation of Antarctic Marine Living Resources, is expected to revisit the proposal in October after failing to agree on previous attempts.

Read more at Seeker

Oldest Human Fossil Outside of Africa Discovered

Close-up view of the Misliya-1 teeth

Common teachings about early human migrations have held for decades that modern Homo sapiens first migrated out of Africa around 60,000 years ago, with descendants of this population and subsequent African migrants later colonizing the farthest reaches of the earth.

Analysis over the past several years of fossils discovered nearly a century ago in the Qafzeh and Es-Skhul Caves in Israel, however, classified them as Homo sapiens dating to about 120,000 years ago. This means that our species was clearly in the Middle East of Asia long before 60,000 years ago.

Now comes the announcement that an international team of researchers has just discovered a modern human fossil — upper jawbone and teeth — from a modern human who lived 177,000–200,000 years ago in Israel. The fossil, called "Misliya" since it was found in Misliya Cave on the western slopes of Mount Carmel, is described in the journal Science.

"Misliya is not just the oldest modern human outside Africa," lead author Israel Hershkovitz of Tel Aviv University told Seeker. "It is the oldest modern human that we know of."

Modern, in reference to Homo sapiens evolution, refers to early members of our species that are most like people today, but the term is a broad one and open to different interpretations.

Excavation of part of Misliya Cave. Evidence for a hearth is at the bottom central-right part of the picture.

At the very least, the newly discovered fossil provides evidence that anatomically modern humans were living outside of Africa 50,000 years earlier than previously thought. The remains were dated by three independent methods (U-series, combined uranium series and electron spin resonance, and thermoluminescence) that all support the early time period.

3D virtual models of the fossil were also created and compared with other hominin fossils from Africa, Europe, and Asia.

"All of the anatomical features in the Misliya fossil are consistent with it being a modern human," co-author Rolf Quam of Binghamton University told Seeker. "There is nothing in the fossil that says to us that it cannot be a Homo sapiens."

The incisor and canine teeth appear to be unique to anatomically modern humans, as does a lack of "shoveling," a thickening of the tooth crown along the edges on the inside surface of the incisor and canine. The latter characteristic has often been seen in archaic human fossils. Quam and his colleagues, though, did identify other features in Misliya that are known to additional human groups, such as Neanderthals.

"However," Quam said, "this does not mean Misliya is a hybrid specimen."

Upper jawbone with teeth from an anatomically modern Homo sapiens found at Misliya Cave, Israel. The remains have been dated to 177,000–194,000 years ago.

The researchers excavated multiple stone tools associated with Misliya. The stone tool "kit" is similar to that found with early, modern Homo sapiens in Africa.

"The most common tools were flint points, many of which were exquisitely retouched and fashioned," Hershkovitz said. "The points were either hafted to serve as the tips of hunting projectiles, or were used for plant processing through the scraping or cutting of plant material, or the digging of plant tubers."

He continued, "The occupants of the site were capable hunters of gazelles, fallow deer, aurochs, wild goats, and other species of deer. Ostrich egg shells were also found."

The scientists determined that the people at Misliya Cave could control the production of fire, based on the remains of a hearth and its ashy sediment. Hearths were repeatedly constructed over many years at the site, suggesting that the cave was in continuous, or near-continuous, use over multiple generations.

Plant materials appear to have been used for bedding or matting, constituting the earliest known evidence for such items.

Hershkovitz and his colleagues are in agreement that the ancestors of Misliya likely originated in North Africa before migrating through the Levant, a region in the Middle East south of the Taurus Mountains, bounded by the Mediterranean Sea on the west and by the northern Arabian Desert and Upper Mesopotamia to the east.

Quam said that the precise source population for the Misliya humans is unknown, "but the oldest fossils attributed to modern humans come from a site known as Jebel Irhoud in Morocco, and date to about 315,000 years ago."

Location of early modern human fossils in Africa and the Middle East

Last year, Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology and his team discovered those fossils, which were reported in the journal Nature. Hublin and his team wrote that the Moroccan evidence “makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the Homo sapiens clade in which key features of modern morphology were established."

The fossils from Morocco, however, exhibit "more primitive neurocranial and endocranial morphology" too, according to Hublin and his team.

Modern, in terms of our species, appears to encompass both an earlier period, represented by the Moroccan finds, and a later period, represented by the Misliya fossils. Which of these ancient groups of humans most resembled people that live today, however, remains in question.

The bigger picture, based on the new findings and prior studies, is that primates first evolved in Asia before some migrated out of the continent. Fossils such as 7.2-million-year-old Graecopithecus freybergi, aka "El Graeco" from Greece and Bulgaria, controversially exhibit human features. The primary hominin lineage leading to the dawn of modern humans, however, is widely thought to have originated in Africa, but not in Morocco.

Composite reconstruction of the Homo sapiens fossils from Jebel Irhoud, Morocco

Phillipp Gunz, co-author of the Nature paper and a Max-Planck Institute for Evolutionary Anthropology scientist, told Seeker, "It is unlikely that Homo sapiens evolved locally in Morocco. Instead, we believe that Homo sapiens evolved somewhere else in Africa and dispersed across the entire continent. This is based on the distribution of the earliest Homo sapiens fossils from North Africa, South Africa, and East Africa, as well as the pan-African distribution of the Middle Stone Age tools."

As these populations dispersed, they likely interbred with other human species in Africa. Homo naledi, for example, may have coexisted for a period of time with Homo sapiens in South Africa, fossils suggest.

Similarly, in Europe and Asia, "modern humans overlapped for a long period of time with existing hominin groups such as Neanderthals, Denisovans, Homo heidelbergensis, and even Homo erectus," Hershkovitz said. "Modern morphology evolved through this interaction."

Read more at Seeker

Modern human brain organization emerged only recently

Brain shape evolution in Homo sapiens: brain shape of one of the earliest known members of our species, the 300,000 year-old cranium Jebel Irhoud 1 (left). Brain shape, and possibly brain function, evolved gradually. Brain morphology has reached the globularity typical for present day humans suprisingly recently (right).

Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, reveal how and when the typical globular brain shape of modern humans evolved. Their analyses based on changes in endocranial size and shape in Homo sapiens fossils show that brain organization, and possibly brain function, evolved gradually within our species and unexpectedly reached modern conditions only recently.

The evolutionary history of our own species can be traced back to fossils from Jebel Irhoud (Morocco) dated to about 300,000 years ago. Last year's analysis of these fossils by researchers from the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig was highlighted as one of the top science stories of 2017 by a diverse range of print and online media. Together with crania from Florisbad (South Africa, 260,000 years old), and Omo Kibish (Ethiopia) dated to 195,000 years ago, the Jebel Irhoud fossils document an early evolutionary phase of Homo sapiens on the African continent. Their face and teeth look modern, however their elongated braincase appears more archaic as in older human species and in Neanderthals. In contrast, it is a globular braincase, which characterizes the skull of present-day modern humans together with small and gracile faces.

In a new paper published in Science Advances, members of the same research team now reveal additional surprising findings about brain evolution in Homo sapiens. The paleoanthropologists Simon Neubauer, Jean-Jacques Hublin and Philipp Gunz used micro computed tomography scans to create virtual imprints of the internal bony braincase, so called endocasts that approximate brain size and shape. They used state-of-art statistics to analyze endocasts of various fossils and present-day humans.

Evolution of the parietal lobe and the cerebellum

Neubauer and colleagues document a gradual change within Homo sapiens, from an elongated endocranial shape towards a more globular one. Two features of this process stand out: parietal and cerebellar bulging. Parietal brain areas are involved in orientation, attention, perception of stimuli, sensorimotor transformations underlying planning, visuospatial integration, imagery, self-awareness, working and long-term memory, numerical processing, and tool use. The cerebellum is not only associated with motor-related functions like the coordination of movements and balance, but also with spatial processing, working memory, language, social cognition, and affective processing.

The Homo sapiens fossils were found to have increasingly more modern endocranial shapes in accordance with their geological age. Only fossils younger than 35,000 years show the same globular shape as present-day humans, suggesting that modern brain organization evolved some time between 100,000 and 35,000 years ago. Importantly, these shape changes evolved independently of brain size -- with endocranial volumes of around 1,400 milliliters, even the oldest Homo sapiens fossils from Jebel Irhoud fell within present-day variation of brain size. "The brain is arguably the most important organ for the abilities that make us human," says Neubauer. But modern human brain shape was not established at the origin of our species together with other key features of craniodental morphology. Neubauer adds: "We already knew that brain shape must have evolved within our own species, but we were surprised to discover just how recent these changes to brain organization were."

Evolutionary changes in early brain development

In present-day humans, the characteristic globular shape of the braincase develops within a few months around the time of birth. Philipp Gunz explains, "The evolution of endocranial shape within Homo sapiens suggests evolutionary changes of early brain development -- a critical period for neural wiring and cognitive development." The researchers therefore argue that evolutionary changes to early brain development were key to the evolution of human cognition. Jean-Jacques Hublin, co-author and director of the Department of Human Evolution at the Max Planck Institute in Leipzig, says: "The gradual evolution of modern human brain shape seems to parallel the gradual emergence of behavioral modernity as seen from the archeological record."

Read more at Science Daily

A new 'atmospheric disequilibrium' could help detect life on other planets

Future telescopes like the James Webb Space Telescope (right) will observe the atmospheres of distant planets to seek evidence of life. Earth (top left) has several gases in its atmosphere that reveal the presence of life, primarily oxygen and ozone. The new study finds that for the early Earth (bottom left), the combination of abundant methane and carbon dioxide would provide an alternative sign of life.

As NASA's James Webb Space Telescope and other new giant telescopes come online they will need novel strategies to look for evidence of life on other planets. A University of Washington study has found a simple approach to look for life that might be more promising than just looking for oxygen.

The paper, published Jan. 24 in Science Advances, offers a new recipe for providing evidence that a distant planet harbors life.

"This idea of looking for atmospheric oxygen as a biosignature has been around for a long time. And it's a good strategy -- it's very hard to make much oxygen without life," said corresponding author Joshua Krissansen-Totton, a UW doctoral student in Earth and space sciences. "But we don't want to put all our eggs in one basket. Even if life is common in the cosmos, we have no idea if it will be life that makes oxygen. The biochemistry of oxygen production is very complex and could be quite rare."

The new study looks at the history of life on Earth, the one inhabited planet we know of, to find times where the planet's atmosphere contained a mixture of gases that are out of equilibrium and could exist only in the presence of living organisms -- anything from pond scum to giant redwoods. In fact, life's ability to make large amounts of oxygen has only occurred in the past one-eighth of Earth's history.

By taking a longer view, the researchers identified a new combination of gases that would provide evidence of life: methane plus carbon dioxide, minus carbon monoxide.

"We need to look for fairly abundant methane and carbon dioxide on a world that has liquid water at its surface, and find an absence of carbon monoxide," said co-author David Catling, a UW professor of Earth and space sciences. "Our study shows that this combination would be a compelling sign of life. What's exciting is that our suggestion is doable, and may lead to the historic discovery of an extraterrestrial biosphere in the not-too-distant future."

The paper looks at all the ways that a planet could produce methane -- from asteroid impacts, outgassing from the planet's interior, reactions of rocks and water -- and finds that it would be hard to produce a lot of methane on a rocky, Earth-like planet without any living organisms.

If methane and carbon dioxide are detected together, especially without carbon monoxide, that's a chemical imbalance that signals life. The carbon atoms in the two molecules represent opposite levels of oxidation. Carbon dioxide holds as many oxygen molecules as it can, while the carbon in methane lacks oxygen and instead has oxygen's chemical adversary, hydrogen.

"So you've got these extreme levels of oxidation. And it's hard to do that through non-biological processes without also producing carbon monoxide, which is intermediate," Krissansen-Totton said. "For example, planets with volcanoes that belch out carbon dioxide and methane will also tend to belch out carbon monoxide."

What's more, carbon monoxide tends not to build up in the atmosphere of a planet that harbors life.

"Carbon monoxide is a gas that would be readily eaten by microbes," Krissansen-Totton said. "So if carbon monoxide were abundant, that would be a clue that perhaps you're looking at a planet that doesn't have biology."

The authors agree that oxygen is a good way to look for signs of life, but think that this new combination is at least as likely to pop up through the new telescopes' sights.

Read more at Science Daily

China Plans to Build the World's Largest Steerable Radio Telescope

China has announced plans to build the world's largest steerable radio telescope. This photo, taken on Sept. 24, 2016, shows the 500-meter Aperture Spherical Telescope in southwest China's Guizhou Province. It is the world's largest non-steerable radio telescope, measuring 500 meters in diameter.

China has announced plans to build the largest steerable radio telescope in the world, the Xinjiang Qitai 110-meter Radio Telescope (QTT), which could provide a huge boost to the search for dark matter, gravitational waves, and extraterrestrial intelligence.

“The QTT’s scientific mission is ambitious,” said Doug Vakoch, president of METI International, an organization that looks to organize the efforts of both searching for and sending out messages to whatever life might be out in the universe. “Recent history shows us that when a radio telescope with radically enhanced characteristics comes online, we make remarkable discoveries.”

China is already the home to the world's largest radio telescope. The FAST, or Five-hundred-meter Aperture Spherical radio Telescope, has been in operation since 2016 and was built in a natural depression in the landscape, similar to the famous Arecibo Telescope in Puerto Rico, and therefore is primarily a fixed position dish. It has, however, a novel, “active surface” design, where metal panels on the surface can be tilted to change the focus to different areas of the sky.

“FAST’s shape-shifting surface can point to a limited extent, but it’s restricted to about 40 degrees of zenith — the point in the celestial sphere that is directly overhead,” Vakoch explained to Seeker. “In contrast, the QTT should be able to pinpoint stars located in three-quarters of the night sky. That means the QTT can examine parts of the heavens that will be forever out of the view of FAST.”

Vakoch said QTT, proposed to be built in the Xinjiang autonomous region of northwest China, will have a slightly larger aperture than the two largest, fully steerable radio telescopes currently in operation. The Robert C. Byrd Green Bank Telescope (GBT) located in Green Bank, West Virginia is currently the largest steerable radio telescope, with an elliptical dish that’s 100 meters by 110 meters. Germany’s Effelsberg dish is 100 meters in diameter.

“The QTT will be only slightly larger, with a diameter of 110 meters in all directions,” Vakoch said. “But we all know how a little added width to a pizza can make a big difference in the number of slices we get from it. So, too, with radio telescopes: A few additional meters of dish size can nudge up your sensitivity, letting you observe fainter astronomical objects.”>

Vakoch said QTT will be able to increase the search for pulsars — the dense, rotating stars that act as cosmic clocks, emitting pulses with remarkable regularity. The QTT may also have the capability to detect gravitational waves from pairs of massive black holes, thanks to its ability to precisely measure the tiny changes of the pulsing rates of pulsars as the gravitational waves pass by.>

As far as searching for extraterrestrial intelligence, Vakoch said QTT will accelerate the search for life beyond Earth in two critical ways.

“By scanning along the radio dial, astronomers will use the QTT to look for the signatures of complex organic molecules in interstellar space,” he said. “These interstellar surveys will show how widely the basic building blocks of life are distributed throughout the cosmos.”

The objects most widely associated with the search for extraterrestrial life, or SETI, are signals from another civilization.

“While naturally occurring radio signals are slightly spread out at their characteristic location on the radio dial,” Vakoch explained, “SETI scientists look for much narrower, artificially produced spikes that leap out as distinctive techno-signatures, unlike anything found in the interstellar medium or in other stars or galaxies.”

By outfitting the QTT with the signal processing capabilities to search for these artificial signals, Vakoch added, astronomers will be able to scan the heavens for signals that could only by created by advanced civilizations. Strategies to foster international cooperation for super-computing capability to sift through a massive amount of cosmic static are in the works, he said.

"A cross-national coordination of data also helps insure the integrity of the data," Vockoch said. "If construction of the QTT remains on schedule, we could start analyzing the instrument’s first data in five years.”

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The Best Tactic for Escaping a Predator — for Impalas and Zebras, at Least

Cheetah hunting zebra in the Manyeleti Conservancy, part of the Greater Kruger National Park.

When a running predator goes after terrestrial prey, the potential victim's best hope for survival is surprisingly not to run as fast as possible, but rather to move in slower, more unpredictable ways that may confuse the would-be attacker.

At least that tactic works best for impalas and zebras hoping to avoid becoming the dinner of lions and cheetahs in their natural savannah habitat. The findings are published in the journal Nature.

"The key thing is not to run flat out when a predator is close and chasing," lead author Alan Wilson of the University of London's Royal Veterinary College (RVC) told Seeker.

Wilson and his team developed collars to track the animals and to record nearly every detail of the movements of nine lions, five cheetahs, seven zebras, and seven impalas in northern Botswana. The animals were darted with a sedative and outfitted with the collars. While the animals were sedated, the scientists removed tiny muscle samples that were later analyzed in the RVC's structure and motion laboratory.

Together, the biopsied muscle bits and collars provided information about five measures of performance: maximum muscle power output and contraction speed, rates of acceleration and deceleration, turn speeds (based on grip and leg strength), how fast each species ran in hunts and the their top speed, and how frequently each species took a step, as each step provides an opportunity to change direction or speed.

A total of 5,562 high-speed runs were analyzed, and the athletic capabilities of the predator-prey pairs, lion-zebra and cheetah-impala, were compared.

The team of scientists found that the cheetahs and impalas were much more athletic than the lions and zebras. These animals' muscles were 20 percent more powerful. They were also 38 percent faster, 37 percent better at accelerating, and 72 percent better at decelerating.

Some of the observed difference is due to a size effect, Wilson said. "Bigger animals tend to be slower," he explained.

Slow is not always so bad, though. Moving in such a way can provide a "big advantage," Wilson said.

A cheetah in northern Botswana wearing a Royal Veterinary College tracking collar. The bottom box (shown) houses the batteries.

Wilson said that predators tend to be faster overall than their prey. They have evolved this particular competitive edge. Cheetahs, for example, are the fastest terrestrial animals. They are able to accelerate to 60 mph in just a few seconds. While they ramp up to top speed, these big cats pump their legs in tandem, bounding until the cheetah reaches a full gallop.

While there were many hunts recorded in the data, there were no instances of a collared predator hunting a collared prey animal. The researchers therefore created a computer model to explore how conditions and tactics affect hunt outcomes. A simulation was used to model the last two strides of a hunt after the predator had gotten close enough to capture prey.

Using the simulation, the researchers determined that lower-speed hunts nearly always favor prey survival. The single best prey strategy was for the impala or zebra to turn suddenly at the last possible moment, making a movement that the predator could not follow. The faster the predator was going, the better the sudden surprise move was for the prey. Confusion in that moment presumably often gives the impala or zebra precious time to escape.

It is also possible that over time, with repeated unexpected prey twists and turns, the lions and cheetahs could give up.

"Neither of the cats are really endurance hunters," said Wilson, who was sometimes able to calmly approach the wild cheetahs, even when they were not sedated. Such moments were captured in the documentary Big Cats, which will debut January 25 on BBC One.

Alan Wilson in Namibia with cheetahs and the RVC research aircraft during filming of the BBC One "Big Cats" program

Even domesticated cats seem to behave in this manner. After eying prey, they may slink to position themselves in an optimal way before pouncing, but then tend to walk away if their initial approach is unsuccessful. Hunting requires a lot of energy. In the wild, conserving such energy can be a life or death matter for predators.

Animal experts have often wondered why lions rarely go after impalas. In addition to finding that impalas are actually more athletic than lions, the researchers' computer simulations determined that impalas can usually escape lion pursuits. The findings help to explain why lions catch impalas opportunistically rather than in open pursuits.

Not all predators, however, suffer from endurance problems.

"Wolves, fox hounds, and deer hounds are reported to be endurance hunters," Wilson said.

Nevertheless, there are many instances of zebras and impalas outwitting predators like wolves with unpredictable moves. It would seem that having a lower fight-or-flight response should benefit prey that are still fit and athletic.

Wilson said that is possible, "but there is the counter argument that being too far away to chase is an even better strategy, hence vigilance and detecting a predator that is looking to hunt is important."

The findings could help wildlife conservationists to better determine how animals hunt, what terrain is preferable for both predators and prey, and other key information affecting the animals' survival. Both lions and cheetahs are considered to be "vulnerable" and threatened with extinction, given that their populations have declined over the years. Loss of habitat, lack of prey and their vulnerability to poachers are just some of the human threats they face.

Wilson said that the new study "would be of help in reintroducing animals" to their known habitats.

A glitch during the research is that the collars were all supposed to drop off when programed to do so. A few did not, forcing the researchers to re-dart the animals and remove the collars by hand.

"It is an issue with a mechanical unit in a hot, dusty, wet environment," Wilson said, admitting that the commercial drop-off units "are very expensive and their reliability is not very good. It is the only part of the collar we don't design ourselves."

This problem did not affect the findings, though. While the collars look to have been rather large and unwieldy, the researchers performed tests prior to the study to determine what device weights and sizes the animals could tolerate without effecting their normal behaviors.

As for how humans fit into the picture, the jury is out concerning whether our early ancestors were more predators or prey. There is some fossil evidence that early humans were regularly hunted by saber-toothed cats, hyenas, and other large carnivores. It is unclear, however, if these predators merely scavenged early human remains.

On the other hand, Wilson said that additional evidence points to humans "evolving to be endurance hunters."

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Nanoparticle vaccine offers universal protection against influenza A viruses, study finds

Vaccine

Researchers have developed a universal vaccine to combat influenza A viruses that produces long-lasting immunity in mice and protects them against the limitations of seasonal flu vaccines, according to a study led by Georgia State University.

Influenza, a contagious respiratory illness that infects the nose, throat and lungs, is among the leading causes of death in the United States, according to the Centers for Disease Control and Prevention (CDC). The CDC estimates influenza has resulted in between 12,000 and 56,000 deaths annually in the U.S. since 2010.

Seasonal flu vaccines must be updated each year to match the influenza viruses that are predicted to be most common during the upcoming flu season, but protection doesn't always meet expectations or new viruses emerge and manufacturers incorrectly guess which viruses will end up spreading. In 2009, the H1N1 pandemic caused 200,000 deaths during the first 12 months, and low vaccine effectiveness was also observed during the 2014-15 and 2016-17 flu seasons. A universal flu vaccine that offers broad protection against various viruses is urgently needed and would eliminate the limitations of seasonal flu vaccines.

Seasonal flu vaccines provide protective immunity against influenza viruses by targeting the exterior head of the virus's surface protein, which is hemagglutinin (HA). The influenza virus trains the body to produce antibodies against inactivated virus particles containing the head of this protein, ideally preventing the head from attaching to receptors and stopping infection. However, the head is highly variable and is different for each virus, creating a need for better vaccines. This study uses a new approach and instead targets the inside portion of the HA protein known as the stalk, which is more conservative and offers the opportunity for universal protection.

In this study, the researchers found vaccinating mice with double-layered protein nanoparticles that target the stalk of this protein produces long-lasting immunity and fully protects them against various influenza A viruses. The findings are published in the journal Nature Communications.

"Vaccination is the most effective way to prevent deaths from influenza virus, but the virus changes very fast and you have to receive a new vaccination each year," said Dr. Bao-Zhong Wang, associate professor in the Institute for Biomedical Sciences at Georgia State. "We're trying to develop a new vaccine approach that eliminates the need for vaccination every year. We're developing a universal influenza vaccine. You wouldn't need to change the vaccine type every year because it's universal and can protect against any influenza virus.

"What we wanted to do is to induce responses to this stalk part of the influenza surface glycoprotein, not the head part. This way you're protected against different viruses because all influenza viruses share this stalk domain. However, this stalk domain itself isn't stable, so we used a very special way to make this vaccine construct with the stalk domain and had success. We assembled this stalk domain into a protein nanoparticle as a vaccine. Once inside, the nanoparticle can protect this antigenic protein so it won't be degraded. Our immune cells have a good ability to take in this nanoparticle, so this nanoparticle is much, much better than a soluble protein to induce immune responses."

The nanoparticles are unique because they were generated to contain almost entirely the protein capable of inducing immune responses. The double layer also better retains the protein function.

To determine the effectiveness of the nanoparticle vaccine, the researchers immunized mice twice with an intramuscular shot. Then, the mice were exposed to several influenza viruses: H1N1, H3N2, H5N1 and H7N9. Immunization provided universal, complete protection against lethal virus exposure and dramatically reduced the amount of virus in the lungs.

Next, the researchers would like to test the nanoparticle vaccine in ferrets, which are similar to humans in the orchestration of their respiratory system.

"This vaccine is composed of very conserved domains. That's the reason why the induced immunity can offer universal protection," said Dr. Lei Deng, first author of the study and a postdoctoral researcher in the Institute for Biomedical Sciences at Georgia State. "The seasonal influenza vaccines induce the dominant immune response against the head domain of the HA molecules, which is hypervariant. That is why we have to adopt new influenza strains for the new vaccine every year. Our vaccine overcomes this problem. For long-term protection, longevity of induced immunity in human still needs to be tested in further clinical tests."

Read more at Science Daily

Chinese Lab Clones the World's First Primates Using Dolly-the-Sheep Technique

This is a photograph of Zhong Zhong, one of the first two monkeys created by somatic cell nuclear transfer.

Geneticists in China announced that they've successfully cloned the first primates using somatic cell nuclear transfer, the same method that produced Dolly, the first cloned sheep more than 20 years ago.

According to a new paper in the journal Cell, the procedure will it make possible for labs to decant large populations of genetically uniform monkeys, which could open up entirely new areas for medical research.

The long-tail macaques, named Zhong Zhong and Hua Hua, were born six and eight weeks ago, respectively. While the monkeys are not the first primates to be cloned — others have been created using a simpler process called embryo splitting — they are the first to ever survive the somatic cell nuclear transfer (SCNT) process. The advantage to this technique, researchers say, is that greater numbers of genetically identical clones can be created in a single batch. This allows geneticists to make isolated changes in the genetic code, then study outcomes among a large population.

“There are a lot of questions about primate biology that can be studied by having this additional model,” said senior author Qiang Sun, director of the Nonhuman Primate Research Facility at the Chinese Academy of Sciences Institute of Neuroscience, in a statement issued with the publication of the new research. "You can produce cloned monkeys with the same genetic background except the gene you manipulated. This will generate real models not just for genetically based brain diseases, but also cancer, immune, or metabolic disorders and allow us to test the efficacy of the drugs for these conditions before clinical use."

This is a photograph of Hua Hua, one of the first monkey clones made by somatic cell nuclear transfer.

When using the SCNT process, scientists remove the nucleus of an egg cell and replace it with another nucleus, which can in turn be taken from various tissue types of either fetal or adult donor specimens. In the case of the Chinese macaques, researchers took fibroblasts — a cell type found in connective tissue — from a single, fetal macaque. As such, the two new monkeys are exact clones of each other, as well as the original specimen.

By comparison, the embryo splitting technique — the one that had been previously used with monkeys — is essentially an artificial approximation of how natural twins develop in mammals. Embryo splitting can only generate up to four offspring at a time, while SCNT clones are theoretically limitless.

In either case, cloned egg cells are placed within surrogate female monkey moms, where the embryos develop and are born naturally.

The research team had previously tried to use adult donor cells with the SCNT method, but the cloned macaques died a few hours after birth. Earlier research established that, for reasons that are still unclear, monkey cell nuclei are more resistant to the SCNT process than other mammals, such as mice and cows.

"We tried several different methods, but only one worked," said Sun. "There was much failure before we found a way to successfully clone a monkey."

The researchers plan to continue improving the technique and generating more macaque clones, using international guidelines for animal research set by the US National Institutes of Health.

“We are very aware that future research using non-human primates anywhere in the world depends on scientists following very strict ethical standards,” said Muming Poo, a co-author of the study.

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Flowers Conquered the World by Downsizing Their Genomes

Typical green Tuscany landscape in Val dOrcia with hills, trees, red poppies, and blue, cloudy sky

For at least two centuries, scientists have been completely stumped as to why flowering plants became dominant so rapidly in ecosystems across the world. As British naturalist Charles Darwin wrote in a July 1879 letter to his son-in-law, Joseph Hooker: "The rapid development as far as we can judge of all the higher plants within recent geological times is an abominable mystery."

The phrase "higher plants" refers to angiosperms, or plants that produce flowers and seeds enclosed within a carpel, which is the female reproductive organ of a flower. They include herbaceous plants, shrubs, grasses, and most trees.

Darwin's "abominable mystery" finally been solved, according to researchers who provide evidence that angiosperms downsized their genomes, which allowed them to decrease their cell sizes to gain a competitive advantage over other plants. The findings are published in the journal PLoS Biology.

"We estimate that over about 50 million years, the minimum size of angiosperm genomes approximately halved," co-author Adam Roddy of Yale University's School of Forestry and Environmental Studies, told Seeker. "This period coincided with decreases in atmospheric carbon dioxide uptake, and because smaller genomes and cells facilitate better carbon dioxide update, selection for small cells was particularly strong."

For their study, Roddy and co-author Kevin Simonin of San Francisco State University's department of biology compiled data for genome size, cell size, stomatal density (the number of stomata, or microscopic pores in leaves), and other information for nearly 400 species of not only angiosperms, but also ferns and gymnosperms. The latter are plants that have seeds unprotected by an ovary or fruit. They include the conifers, cycads, and ginkgo.

The researchers found that genome downsizing began about 140 million years ago. The world's oldest known flowering plant, Montsechia vidalii, dates to 10 million years later in the fossil record. Flowers likely emerged much earlier than this specimen, however. This overall period, when dinosaurs were still flourishing, corresponds to the spread of angiosperms around the globe.

A large intact specimen of the fossil Montsechia vidalii

As for why smaller genomes can result in smaller cells, the scientists said that there is not necessarily any link between plant size and either genome or cell size.

"However," Roddy said, "there is a strong link between genome size and cell size because the minimum size of a cell is defined by the size of the nucleus, where the genome resides. So, genome size acts as a hard, lower boundary on the minimum size of the cells."

The same phenomenon occurs in animals and all other eukaryotes, prior research suggests. The human genome contains about 3 billion chemical units of DNA, or base pairs. In contrast, the seemingly simple small creature Amoeba dubia has 670 billion base pairs, according to the organization Genome News Network.

Numerous factors aside from genome size can affect cell size, though, such as environmental conditions and biological factors. Having small cells is not even always beneficial because plenty of functions may require large cells.

"For example," Roddy said, "desert plants frequently store water inside their cells to tolerate prolonged drought conditions, and this means they have large cells."

Nevertheless, smaller genomes — and therefore smaller cells — have proven to be very beneficial to flowering plants. Their emergence irrevocably altered global climate and all life on Earth.

The scientists explained that because of their high metabolic rates, flowering plants promote faster rates of cycling of water, carbon, and nutrients. Many angiosperms are also annual plants, which rely on short life cycles and fast physiological rates. Flowering plants may help to maintain wetter, less seasonal tropical forests, due to their higher transpiration rates.

"Furthermore, the angiosperms are the basis of our global food supply," Roddy said. "Humanity would not survive without them."

A mechanical dinosaur display at the Natural History Museum of Leiden

Non-avian dinosaurs, conversely, existed long before the emergence of angiosperms. These once numerous animals are theorized to have eaten ferns, ginkgoes, conifers and related plants — many of which were driven to extinction by angiosperms with their anatomical advantage. Could flowers then have helped to drive non-avian dinosaurs and other animals to extinction? That remains a possibility.

"The ferns and conifers that remain live predominantly in marginal habitats that have low productivity," Roddy said, explaining that "productivity" refers to processes like photosynthesis and growth.

"In these habitats," he continued, "survival may be due less to having a competitive edge than to being persistent and able to survive long periods of stress."

For example, boreal forests that have long, cold winters are dominated by conifers. Ferns, on the other hand, often live in very dark forest understories, or in dry rock crevices.

"It's not to say that there aren't also angiosperms that inhabit similar habitats, but rather that these marginalized habitats are not driven by intense competition," Roddy said.

Simonin added that flowering plants today are not the dominant player in every terrestrial ecosystem, yet in environments that can support high rates of productivity, "angiosperms are well suited to take advantage of this and thus have a competitive edge over the other major groups of land plants."

In the future, the findings related to genome and cell sizes could benefit crop breeding programs, leading to plants with even more enhanced potential for growth and water-use efficiency.

Georgia aster (Symphyotrichum georgianum), a flowering plant that has been in decline for decades due to human-caused threats, such as habitat loss

Many questions remain, though, such as how angiosperms are able to so sufficiently reduce their genome size.

"Most whole plant genomes that have been sequenced have been done, not surprisingly, on species with relatively small genomes because this smaller size makes it easier," Simonin said. "However, to really understand what is taking place during these genome rearrangements we also need to sequence the genomes of species with relatively large genomes."

The researchers also want to determine how genome size influences the ability of plants to respond to environmental changes associated with global climate change.

Angiosperms clearly survived the major extinction event that wiped out non-avian dinosaurs and numerous other animals around 66 million years ago, but some of the most endangered plants now are flowers. They include the Western prairie fringed orchid, rafflesia flower, Georgia aster, Howell's spectacular thelypody, and Ouachita mountain goldenrod.

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Mysterious Hypatia Stone Compounds Are Not Found Anywhere in Our Solar System

Researchers Jan Kramers and Georgy Belyanin found mineral compounds unlike anything on Earth, or in known meteorites or comets, in these fragments from the Hypatia stone, which was picked up in southwest Egypt in the Libyan Desert Glass Field.

A small meteorite that landed on Earth approximately 28.5 million years ago may be giving scientists an unprecedented glimpse into the time before our solar system even formed. But the findings are confounding the prevailing theories about the pre-solar dust cloud where the sun, Earth, and other planets were born.

The Hypatia stone was found in southwest Egypt in 1996, and several studies show that it contains an unusual mix of small mineral compounds that are not known to occur on Earth — or elsewhere in the solar system, for that matter. And the compounds haven’t been found in other meteorites either or in any data we have about comets, either, according to researchers from the University of Johannesburg. While there are many types of meteorites, Hypatia is unlike any other meteorite in almost every aspect.

"If it were possible to grind up the entire planet Earth to dust in a huge mortar and pestle, we would get dust with, on average, a similar chemical composition as chondritic meteorites," said researcher Jan Kramers, in a statement. "In chondritic meteorites, we expect to see a small amount of carbon and a good amount of silicon. But Hypatia's matrix has a massive amount of carbon and an unusually small amount of silicon."

Additionally, dust grains embedded in the rock contains a high amount of carbon compounds, called polyaromatic hydrocarbons, which are a major component of the interstellar dust that existed even before our solar system was formed, the researchers said.

The Hypatia stone was named after Hypatia of Alexandria, a 3rd-century female astronomer, mathematician, and inventor. Previous tests on the rock confirmed that it was of extraterrestrial origin, and with its unusual composition, it was at one time thought to be from the nucleus of a comet.

Hypatia contains microscopic diamonds, which likely formed in the shock of impact with Earth's atmosphere or surface. These diamonds make Hypatia extremely hard and resistant to weathering. In fact, when Kramers and his colleague Georgy Belyanin tried to cut the rock with an industrial diamond polisher, the stone destroyed the cutting disk in about ten minutes.

“Once we were able start our chemical analysis,” Belyanin said in a video, “we managed to look deep inside the stone this time. Besides carbon we found nickel, phosphorus, iron, and sulfur were present in significant amounts in the stone and the chemical compounds were very unusual, [ones] never reported as present on Earth or in extraterrestrial material like meteorites. So that makes Hypatia a very unusual and specific stone.”

Together, these factors lead the team to conclude that Hypatia is an assembly of unchanged pre-solar material. But if that view of Hypatia holds up, that pre-solar material may be different than originally thought.

The prevailing theory says our solar system's planets formed from the solar nebula, a huge, ancient cloud of interstellar dust. The solar nebula should be homogenous, with the same kind of dust everywhere.

But Hypatia's chemistry questions that view.

“If Hypatia itself is not pre-solar, the features indicate that the solar nebula wasn't the same kind of dust everywhere,” said Kramers, “which starts tugging at the generally accepted view of the formation of our solar system.”

There has also been some speculation that Hypatia could have come from outside our solar system. The researchers also found moissanite in the stone, which is a silicon carbide known to flow out in the solar wind of large, red giant stars called Asymptotic Giant Branch stars.

The first known interstellar asteroid, 1I/2017 U1, aka Oumuamua, flew past Earth in October 2017 and shows extra-solar, “alien” material invading our solar system isn’t completely out of the question.

But no one should jump to any conclusions, University of Central Florida planetary physicist Philip Metzger told Seeker.

“You don’t want to be like the guy that says, ‘I don’t want to say it’s aliens, but it’s aliens,’” Metzger, who is not involved in the Hypatia research, said. “Is this rock possibly from outside the solar system? Parts of it almost certainly are but that’s not unusual. A lot of material in the solar system contains pre-solar grains.”

But, Metzger added, the pre-solar grains in Hyptia are different than anything we’ve seen before.

Read more at Seeker

New limit on the definition of a planet proposed

Pluto hogs the spotlight in the continuing scientific debate over what is and what is not a planet, but a less conspicuous argument rages on about the planetary status of massive objects outside our solar system. The dispute is not just about semantics, as it is closely related to how giant planets like Jupiter form.

Johns Hopkins University astrophysicist Kevin Schlaufman aims to settle the dispute.

In a paper just published by the Astrophysical Journal, Schlaufman has set the upper boundary of planet mass between four and 10 times the mass of the planet Jupiter.

Schlaufman, an assistant professor in the university's Department of Physics and Astronomy, says setting a limit is possible now mainly due to improvements in the technology and techniques of astronomical observation. The advancements have made it possible to discover many more planetary systems outside our solar system and therefore possible to see robust patterns that lead to new revelations.

"While we think we know how planets form in a big-picture sense, there's still a lot of detail we need to fill in," Schlaufman said. "An upper boundary on the masses of planets is one of the most prominent details that was missing."

The conclusions in the new paper are based on observations of 146 solar systems, Schlaufman said. Almost all the data he used was measured in a uniform way, he said. The data are more consistent from one solar system to the next, and so more reliable.

Defining a planet, distinguishing it from other celestial objects, is a bit like narrowing down a list of criminal suspects. It's one thing to know you're looking for someone who is taller than 5-foot-8, it's another to know your suspect is between 5-foot-8 and 5-foot-10.

In this instance, investigators want to distinguish between two suspects: a giant planet and a celestial object called a brown dwarf. Brown dwarfs are more massive than planets, but less massive than the smallest stars. They are thought to form as stars do.

For decades brown dwarfs have posed a problem for scientists: how to distinguish low-mass brown dwarfs from especially massive planets? Mass alone isn't enough to tell the difference bzween the two, Schlaufman said. Some other property was needed to draw the line.

In Schlaufman's new argument, the missing property is the chemical makeup of a solar system's own sun. He says you can know your suspect, a planet, not just by itssize, but also by the company it keeps. Giant planets such as Jupiter are almost always found orbiting stars that have more iron than our sun. Brown dwarfs are not so discriminating.

That's where his argument engages the idea of planet formation. Planets like Jupiter are formed from the bottom-up by first building-up a rocky core that is subsequently enshrouded in a massive gaseous envelope. It stands to reason that they would be found near stars heavy with elements that make rocks, as those elements provide the seed material for planet formation. Not so with brown dwarfs.

Brown dwarfs and stars form from the top-down as clouds of gas collapse under their own weight.

Schlaufman's idea was to find the mass at which objects stop caring about the composition of the star they orbit. He found that objects more massive than about 10 times the mass of Jupiter do not prefer stars with lots of elements that make rocks and therefore are unlikely to form like planets.

Read more at Science Daily

New Eocene fossil data suggest climate models may underestimate future polar warming

Foraminifera, small single-celled marine organisms, form their shells in concert with the ocean's temperature and chemistry. Like tiny time capsules, they can reveal the climate conditions of millions of years ago.

A new international analysis of marine fossils shows that warming of the polar oceans during the Eocene, a greenhouse period that provides a glimpse of Earth's potential future climate, was greater than previously thought.

By studying the chemical composition of fossilized foraminifera, tiny single-celled animals that lived in shallow tropical waters, a team of researchers generated precise estimates of tropical sea surface temperatures and seawater chemistry during the Eocene Epoch, 56-34 million years ago. Using these data, researchers fine-tuned estimates from previous foram studies that captured polar conditions to show tropical oceans warmed substantially in the Eocene, but not as much as polar oceans.

Importantly, when modern climate models -- the same as those used in the United Nations' recent Intergovernmental Panel on Climate Change reports -- were run under Eocene conditions, many could not replicate these findings. Instead, the models consistently underestimated polar ocean warming in the Eocene.

This discrepancy may result from a gap in our understanding of the climate system or from what we know about the Eocene, said David Evans, the study's lead author and Leverhulme Research Fellow at the University of St Andrews' School of Earth and Environmental Sciences. If it does indeed relate to the climate system, it raises the possibility that predictions of future polar warming are also too low.

"Yes, the tropics are warming but nowhere near to the same degree as the polar regions," Evans said. "That's something we really need to be able to understand and replicate in climate models. The fact that many models are unable to do that at the moment is worrying."

The researchers published their findings this week in the Proceedings of the National Academy of Sciences.

Scientists frequently look to the Eocene to understand how the Earth responds to higher levels of carbon dioxide. During the Eocene, the concentration of carbon dioxide in the atmosphere was more than 560 parts per million, at least twice preindustrial levels, and the epoch kicked off with a global average temperature more than 8 degrees Celsius -- about 14 degrees Fahrenheit -- warmer than today, gradually cooling over the next 22 million years. These characteristics make the Eocene a good period on which to test our understanding of the climate system, said Laura Cotton, study co-author and curator of micropaleontology at the Florida Museum of Natural History.

One of the challenges has been accurately determining the difference between sea surface temperatures at the poles and the equator during the Eocene, with models predicting greater differences than data suggested.

The research team used large bottom-dwelling forams as "paleothermometers" to gain a more precise temperature reading. Forams have an exceptionally long fossil record, spanning more than 540 million years, and they are often well-preserved in ocean sediments. Most are small enough to fit into the eye of a needle -- Cotton describes them as "an amoeba with a shell" -- but they were so abundant during the Eocene that there are entire rocks composed of them.

"If you look at the pyramids, they're full of these tiny little lentil-like things -- those are forams," Cotton said. "The ancient Greeks thought the pyramids were made from the fossilized lentils of slaves, but it's just the limestone from one of these deposits that is absolutely filled with them."

Forams form their shells in concert with ocean temperatures and chemistry, acting as miniscule time capsules, each containing a precise record of the temperature and ocean chemistry during its lifetime. Their shells are primarily made of calcium, carbon and oxygen. Heavy isotopes of carbon and oxygen bond together as a foram makes its shell -- the cooler the temperature, the more they bond to each other.

By analyzing these clumped isotopes from fossil specimens found in India, Indonesia and Tanzania, the researchers could get an accurate reading of sea surface temperature across the tropics in the Eocene. They also lasered a small hole in each specimen to measure the amount of magnesium and calcium that vaporized, revealing the seawater chemistry.

They found that tropical sea surface temperature in the Eocene was about 6 degrees Celsius -- about 10 degrees Fahrenheit -- warmer than today.

"This was the first time we had samples that were good enough and this method was well-known enough that it could all come together," Cotton said.

The team then used their dataset from the tropics to back-calculate the temperature and chemistry of polar oceans, relying on previous studies of forams that captured the conditions of those regions.

With this correction factor in place, they investigated the degree to which polar oceans warmed more than the tropics, a feature of the climate system known as polar amplification. Their data showed that the difference between polar and equatorial sea surface temperatures in the Eocene was an estimated 20 degrees Celsius, about 36 degrees Fahrenheit. Today the difference is 28 degrees Celsius, indicating that polar regions are more sensitive to increases in atmospheric carbon dioxide than the tropics.

Troublingly, said Evans, when the team compared their data with various modern climate models under Eocene conditions, most models underestimated polar amplification by about 50 percent.

The two models that came closest to reproducing the team's data had one key aspect in common -- they modified the way they accounted for cloud formation and the longevity of clouds in the atmosphere, particularly in the polar regions.

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