The Great London [Search results for new life] 

Extra-terrestrials that resemble humans should have evolved on other, Earth-like planets, making it increasingly paradoxical that we still appear to be alone in the universe, the author of a new study on convergent evolution has claimed.

The argument is one of several that emerge from The Runes Of Evolution, a new book in which the leading evolutionary biologist, Professor Simon Conway Morris, makes the case for a ubiquitous "map of life" that governs the way in which all living things develop.

It builds on the established principle of convergent evolution, a widely-supported theory -- although one still disputed by some biologists -- that different species will independently evolve similar features.

Conway Morris argues that convergence is not just common, but everywhere, and that it has governed every aspect of life's development on Earth. Proteins, eyes, limbs, intelligence, tool-making -- even our capacity to experience orgasms -- are, he argues, inevitable once life emerges.

The book claims that evolution is therefore far from random, but a predictable process that operates according to a fairly rigid set of rules.

If that is the case, then it follows that life similar to that on Earth would also develop in the right conditions on other, equivalent planets. Given the growing number of Earth-like planets of which astronomers are now aware, it is increasingly extraordinary that aliens that look and behave something like us have not been found, he suggests.

"Convergence is one of the best arguments for Darwinian adaptation, but its sheer ubiquity has not been appreciated," Professor Conway Morris, who is a Fellow at St John's College, University of Cambridge, said.

"Often, research into convergence is accompanied by exclamations of surprise, describing it as uncanny, remarkable and astonishing. In fact it is everywhere, and that is a remarkable indication that evolution is far from a random process. And if the outcomes of evolution are at least broadly predictable, then what applies on Earth will apply across the Milky Way, and beyond."

Professor Conway Morris has previously raised the prospect that alien life, if out there, would resemble earthlings -- with limbs, heads, and bodies -- notably at a Royal Society Conference in London in 2010. His new book goes even further, however, adding that any Earth-like planet should also evolve thunniform predators (like sharks), pitcher plants, mangroves, and mushrooms, among many other things.

Limbs, brains and intelligence would, similarly, be "almost guaranteed." The traits of human-like intelligence have evolved in other species -- the octopus and some birds, for example, both exhibit social playfulness -- and this, the book suggests, indicates that intelligence is an inevitable consequence of evolution that would characterise extraterrestrials as well.

Underpinning this is Conway Morris' claim that convergence is demonstrable at every major stepping stone in evolutionary history, from early cells, through to the emergence of tissues, sensory systems, limbs, and the ability to make and use tools.

The theory, in essence, is that different species will evolve similar solutions to problems via different paths. A commonly-cited example is the octopus, which has evolved a camera eye that is closely similar to that of humans, although distinctive in important ways that reflect its own history. Although octopi and humans have a common ancestor, possibly a slug-like creature, this lived 550 million years ago and lacked numerous complex features that the two now share. The camera eye of each must therefore have evolved independently.

Conway Morris argues that this process provides an underlying evolutionary framework that defines all life, and leads to innumerable surprises in the natural world. The book cites examples such as collagen, the protein found in connective tissue, which has emerged independently in both fungi and bacteria; or the fact that fruit flies seem to get drunk in the same manner as humans. So too the capacity for disgust in humans -- a hard-wired instinct helping us avoid infection and disease -- is also exhibited by leaf-cutter ants.

The study also identifies many less obvious evolutionary "analogues," where species have evolved certain properties and characteristics that do not appear to be alike, but are actually very similar. For example, "woodpeckerlike habits" are seen in lemurs and extinct marsupials, while the mechanics of an octopus' tentacles are far closer to those of a human arm than we might expect, and even their suckers can operate rather like hands.

Conway Morris contends that all life navigates across this evolutionary map, the basis of what he describes as a "predictive biology." "Biology travels through history," he writes, "but ends up at much the same destination."

This, however, raises fascinating and problematic questions about the possibility of life occurring on other planets. "The number of Earth-like planets seems to be far greater than was thought possible even a few years ago," Conway Morris said. "That doesn't necessarily mean that they have life, because we don't necessarily understand how life originates. The consensus offered by convergence, however, is that life is going to evolve wherever it can."

"I would argue that in any habitable zone that doesn't boil or freeze, intelligent life is going to emerge, because intelligence is convergent. One can say with reasonable confidence that the likelihood of something analogous to a human evolving is really pretty high. And given the number of potential planets that we now have good reason to think exist, even if the dice only come up the right way every one in 100 throws, that still leads to a very large number of intelligences scattered around, that are likely to be similar to us."

If this is so, as the book suggests in its introduction, then it makes Enrico Fermi's famous paradox -- why, if aliens exist, we have not yet been contacted -- even more perplexing. "The almost-certainty of ET being out there means that something does not add up, and badly," Conway Morris said. "We should not be alone, but we are."

The Runes Of Evolution was six years in the making and draws on thousands of academic sources, and throws up numerous other, surprising findings as well. Sabre-teeth, for example, turn out to be convergent, and Conway Morris explains why it is that the clouded leopard of Asia, Neofelis nebulosa, has developed features that could, as it evolves "presage the emergence of a new sabre-tooth," although sadly it looks set to become extinct before this happens. Elsewhere, the study suggests that certain prehistoric creatures other than bats and birds may have attempted to evolve flight.

"It makes people slightly uneasy that evolution can end up reaching the same solutions to questions about how to catch something, how to digest something, and how to work," Conway Morris added. "But while the number of possibilities in evolution in principle is more than astronomical, the number that actually work is an infinitesimally smaller fraction."

The Runes Of Evolution, by Simon Conway Morris, is published by Templeton Press

Source: University of Cambridge [July 02, 2015]

It took 100 million years for oxygen levels in the oceans and atmosphere to increase to the level that allowed the explosion of animal life on Earth about 600 million years ago, according to a UCL-led study funded by the Natural Environment Research Council.

Before now it was not known how quickly Earth's oceans and atmosphere became oxygenated and if animal life expanded before or after oxygen levels rose. The new study, published today in Nature Communications, shows the increase began significantly earlier than previously thought and occurred in fits and starts spread over a vast period. It is therefore likely that early animal evolution was kick-started by increased amounts of oxygen, rather than a change in animal behaviour leading to oxygenation.

Lead researcher, Dr Philip Pogge von Strandmann (UCL Earth Sciences), said: "We want to find out how the evolution of life links to the evolution of our climate. The question on how strongly life has actively modified Earth's climate, and why the Earth has been habitable for so long is extremely important for understanding both the climate system, and why life is on Earth in the first place."

Researchers from UCL, Birkbeck, Bristol University, University of Washington, University of Leeds, Utah State University and University of Southern Denmark tracked what was happening with oxygen levels globally 770 - 520 million years ago (Ma) using new tracers in rocks across the US, Canada and China.

Samples of rocks that were laid down under the sea at different times were taken from different locations to piece together the global picture of the oxygen levels of Earth's oceans and atmosphere. By measuring selenium isotopes in the rocks, the team revealed that it took 100 million years for the amount of oxygen in the atmosphere to climb from less than 1% to over 10% of today's current level. This was arguably the most significant oxygenation event in Earth history because it ushered in an age of animal life that continues to this day.

Dr Pogge von Strandmann, said: "We took a new approach by using selenium isotope tracers to analyse marine shales which gave us more information about the gradual changes in oxygen levels than is possible using the more conventional techniques used previously. We were surprised to see how long it took Earth to produce oxygen and our findings dispel theories that it was a quick process caused by a change in animal behaviour."

During the period studied, three big 'snowball Earth' glaciations - Sturtian (~716Ma), Marinoan (~635Ma) and Gaskiers (~580Ma) - occurred whereby the Earth's land was covered in ice and most of the oceans were frozen from the poles to the tropics. During these periods, temperatures plummeted and rose again, causing glacial melting and an influx of nutrients into the ocean, which researchers think caused oxygen levels to rise deep in the oceans.

Increased nutrients means more ocean plankton, which will bury organic carbon in seafloor sediments when they die. Burying carbon results in oxygen increasing, dramatically changing conditions on Earth. Until now, oxygenation was thought to have occurred after the relatively small Gaskiers glaciation melted. The findings from this study pushes it much earlier, to the Marinoan glaciation, after which animals began to flourish in the improved conditions, leading to the first big expansion of animal life.

Co-author Prof. David Catling (University of Washington Earth and Space Sciences), added: "Oxygen was like a slow fuse to the explosion of animal life. Around 635 Ma, enough oxygen probably existed to support tiny sponges. Then, after 580 Ma, strange creatures shaped like pizzas lived on a lightly oxygenated seafloor. Fifty million years later, vertebrate ancestors were gliding through oxygen-rich seawater. Tracking how oxygen increased is the first step towards understanding why it took so long. Ultimately, a grasp of geologic controls on oxygen levels can help us understand whether animal-like life might exist or not on Earth-like planets elsewhere."

Source: University College London [December 17, 2015]

Medical scanners and the same software used to assess building strength after the Canterbury earthquakes, have revealed new information about the diet and dining preferences of New Zealand's extinct moa.

Researchers from Canterbury Museum, the University of Auckland, Finders University and the Universities of New England (Australia) and New South Wales have discovered that the nine species of moa were able to co-exist because differences in the structure and strength of each species' skull and bills were influenced by, or dictated by, diet.

The findings are published today in the journal >Proceedings of the Royal Society, in London.

Co-author, Dr Peter Johnston from the University of Auckland's Anatomy and Medical Imaging department, made MRI scans of the mummified moa remains to allow accurate models to be made for the research.

The moa, which roamed New Zealand until the 15th century, were herbivores and some of the largest birds to have ever existed. The largest species, the South Island Giant moa, weighed up to 240 kg whilst the smallest (the upland moa) was the size of a sheep.

Until now scientists had thought that the huge difference in size between the species determined their foraging behaviour as well as what, when and where they ate (ie their ecological niche).

Co-author Professor Paul Scofield from Canterbury Museum says that the team took the most complete skulls of each species of moa from the collections of Canterbury Museum and Te Papa Tongarewa and scanned those using medical CT (Computed Tomography) scanners.

"We then produced highly accurate 3D models of each. This wasn't a simple job as we didn't have a single skull that was perfect so we used sophisticated digital cloning techniques to digitally reconstruct accurate osteological models for each species," Professor Scofield said.

Using the medical MRI scans of the mummified remains, Dr Johnston digitally reconstructed the muscles of each species.

"Each moa species has a characteristic bill shape and the reasons for this have not previously been defined," says Dr Johnston. "Charles Darwin had an easier time investigating a similar situation in Galapagos finches, as the differences are more extreme and the diets are obvious in that group of birds."

Software used by civil engineers after the Canterbury Earthquakes to identify weak or unsound buildings, was used to test the strength and structure of each moa species' bill.

These were compared to each other and to two living relatives, the emu and cassowary. The models simulated the response of the skull to different biting and feeding behaviours including clipping twigs and pulling, twisting or bowing head motions to remove foliage.

The skull mechanics of moa were found to be surprisingly diverse. The little bush moa had a relatively short, sharp-edged bill and was superior among moa at cutting twigs and branches, supporting the proposition that they primarily fed on fibrous material from trees and shrubs.

At the opposite extreme, the coastal moa had a relatively weak skull compared to all other species which may have forced them to travel further than other moa in search of suitable food, such as soft fruit and leaves.

Dr Trevor Worthy (a New Zealander working at Flinders University in Australia) says "until now we have been limited in assessing anatomical function to examining the external aspect of bones. This new technology allows us to bring new life to old bones and to get one step closer to understanding the birds they came from."

"Little has been known about how New Zealand's ecosystem evolved, largely because we know so little about how moa lived and co-existed," says Associate Professor Stephen Wroe, leader of the Function, Evolution and Anatomy Research (FEAR) laboratory at the University of New England (Australia).

"This new research advances our understanding about the feeding behaviours of the moa species and their impact on New Zealand's unique and distinctive flora."

Source: University of Auckland [January 14, 2016]

The world's attention is now on Proxima Centauri b, a possibly Earth-like planet orbiting the closest star, 4.22 light-years away. The planet's orbit is just right to allow liquid water on its surface, needed for life. But could it in fact be habitable?

If life is possible there, the planet evolved very different than Earth, say researchers at the University of Washington-based Virtual Planetary Laboratory (VPL) where astronomers, geophysicists, climatologists, evolutionary biologists and others team to study how distant planets might host life.

Astronomers at Queen Mary University in London have announced discovery of Proxima Centauri b, a planet orbiting close to a star 4.22 light-years away. The find has been called "the biggest exoplanet discovery since the discovery of exoplanets."

Rory Barnes, UW research assistant professor of astronomy, published a discussion about the discovery at palereddot.org, a website dedicated to the search for life around Proxima Centauri. His essay describes research underway through the UW planetary lab -- part of the NASA Astrobiology Institute -- to answer the question, is life possible on this world?

"The short answer is, it's complicated," Barnes writes. "Our observations are few, and what we do know allows for a dizzying array of possibilities" -- and almost as many questions.

The Virtual Planetary Laboratory is directed by Victoria Meadows, UW professor of astronomy. UW-affiliated researchers include Giada Arney, Edward Schwieterman and Rodrigo Luger. Using computer models, the researchers studied clues from the orbits of the planet, its system, its host star and apparent companion stars Alpha Centauri A and B -- plus what is known of stellar evolution to begin evaluating Proxima b's chances.

Relatively little is known about Proxima:

• It's at least as massive as Earth and may be several times more massive, and its "year" -- the time it takes to orbit its star -- is only 11 days

• Its star is only 12 percent as massive as our sun and much dimmer (so its habitable zone, allowing liquid water on the surface, is much closer in) and the planet is 25 times closer in than Earth is to our sun

• The star may form a third part of the Alpha Centauri binary star system, separated by a distance of 15,000 "astronomical units," which could affect the planet's orbit and history

• The new data hint at the existence of a second planet in the system with an orbital period near 200 days, but this has not been proven

Perhaps the biggest obstacle to life on the planet, Barnes writes, is the brightness of its host star. Proxima Centauri, a red dwarf star, is comparatively dim, but wasn't always so.

"Proxima's brightness evolution has been slow and complicated," Barnes writes. "Stellar evolution models all predict that for the first one billion years Proxima slowly dimmed to its current brightness, which implies that for about the first quarter of a billion years, planet b's surface would have been too hot for Earth-like conditions."

Barnes notes that he and UW graduate student Rodrigo Luger recently showed that had modern Earth been in such a situation, "it would have become a Venus-like world, in a runaway greenhouse state that can destroy all of the planet's primordial water," thus extinguishing any chance for life.

Next come a host of questions about the planet's makeup, location and history, and the team's work toward discerning answers.

• Is the planet "rocky" like Earth? Most orbits simulated by the planetary lab suggest it could be -- and thus can host water in liquid form, a prerequisite for life

• Where did it form, and was there water? Whether it formed in place or farther from its star, where ice is more likely, VPL researchers believe it is "entirely possible" Proxima b could be water-rich, though they are not certain.

• Did it start out as a hydrogen-enveloped Neptune-like planet and then lose its hydrogen to become Earth-like? VPL research shows this is indeed possible, and could be a viable pathway to habitability

• Proxima Centauri flares more often than our sun; might such flares have long-since burned away atmospheric ozone that might protect the surface and any life? This is possible, though a strong magnetic field, as Earth has, could protect the surface.

Also, any life under even a few meters of liquid water would be protected from radiation.

Another concern is that the planet might be tidally locked, meaning one side permanently faces its star, as the moon does Earth. Astronomers long thought this to mean a world could not support life, but now believe planetwide atmospheric winds would transport heat around the planet.

"These questions are central to unlocking Proxima's potential habitability and determining if our nearest galactic neighbor is an inhospitable wasteland, an inhabited planet, or a future home for humanity," Barnes writes.

Planetary laboratory researchers also are developing techniques to determine whether Proxima b's atmosphere is amenable to life.

"Nearly all the components of an atmosphere imprint their presence in a spectrum (of light)," Barnes writes. "So with our knowledge of the possible histories of this planet, we can begin to develop instruments and plan observations that pinpoint the critical differences."

At high enough pressures, he notes, oxygen molecules can momentarily bind to each other to produce an observable feature in the light spectrum.

"Crucially, the pressures required to be detectable are large enough to discriminate between a planet with too much oxygen, and one with just the right amount for life.

As we learn more about the planet and the system, we can build a library of possible spectra from which to quantitatively determine how likely it is that life exists on planet b."

Our own sun is expected to burn out in about 4 billion years, but Proxima Centauri has a much better forecast, perhaps burning for 4 trillion years longer.

"If Proxima b is habitable, then it might be an ideal place to move. Perhaps we have just discovered a future home for humanity. But in order to know for sure, we must make more observations, run many more computer simulations and, hopefully, send probes to perform the first direct reconnaissance of an exoplanet," Barnes writes. "The challenges are huge, but Proxima b offers a bounty of possibilities that fills me with wonder."

Proxima Centauri b may be the first exoplanet to be directly characterized by powerful ground- and space-based telescopes planned for the future, and its atmosphere spectroscopically probed for active biology. The research was funded by the NASA Astrobiology Institute. "Whether habitable or not," Barnes concludes, "Proxima Centauri b offers a new glimpse into how the planets and life fit into our universe."

Author: Peter Kelley | Source: University of Washington [August 30, 2016]

The human-dominated geological epoch known as the Anthropocene probably began around the year 1610, with an unusual drop in atmospheric carbon dioxide and the irreversible exchange of species between the New and Old Worlds, according to new research published today in Nature.

Previous epochs began and ended due to factors including meteorite strikes, sustained volcanic eruptions and the shifting of the continents. Human actions are now changing the planet, but are we really a geological force of nature driving Earth into a new epoch that will last millions of years?

Scientists at UCL have concluded that humans have become a geological power and suggest that human actions have produced a new geological epoch.

Defining an epoch requires two main criteria to be met. Long-lasting changes to the Earth must be documented. Scientists must also pinpoint and date a global environmental change that has been captured in natural material, such as rocks, ancient ice or sediment from the ocean floor. Such a marker -- like the chemical signature left by the meteorite strike that wiped out the dinosaurs -- is called a golden spike.

The study authors systematically compared the major environmental impacts of human activity over the past 50,000 years against these two formal requirements. Just two dates met the criteria: 1610, when the collision of the New and Old Worlds a century earlier was first felt globally; and 1964, associated with the fallout from nuclear weapons tests. The researchers conclude that 1610 is the stronger candidate.

The scientists say the 1492 arrival of Europeans in the Americas, and subsequent global trade, moved species to new continents and oceans, resulting in a global re-ordering of life on Earth. This rapid, repeated, cross-ocean exchange of species is without precedent in Earth's history.

They argue that the joining of the two hemispheres is an unambiguous event after which the impacts of human activity became global and set Earth on a new trajectory. The first fossil pollen of maize, a Latin American species, appears in marine sediment in Europe in 1600, becoming common over subsequent centuries. This irreversible exchange of species satisfies the first criteria for dating an epoch -- long-term changes to Earth.

The Anthropocene probably began when species jumped continents, starting when the Old World met the New. We humans are now a geological power in our own right -- as Earth-changing as a meteorite strike

The researchers also found a golden spike that can be dated to the same time: a pronounced dip in atmospheric carbon dioxide centred on 1610 and captured in Antarctic ice-core records. The drop occurred as a direct result of the arrival of Europeans in the Americas. Colonisation of the New World led to the deaths of about 50 million indigenous people, most within a few decades of the 16th century due to smallpox. The abrupt near-cessation of farming across the continent and the subsequent re-growth of Latin American forests and other vegetation removed enough carbon dioxide from the atmosphere to produce a drop in CO2. Thus, the second requirement of a golden spike marker is met.

The researchers have named the 1610 dip in carbon dioxide the 'Orbis Spike'. They chose the Latin word for 'world' because this golden spike was caused by once-disconnected peoples becoming globally linked.

Lead author, Dr Simon Lewis (UCL Geography and University of Leeds), said: "In a hundred thousand years scientists will look at the environmental record and know something remarkable happened in the second half of the second millennium. They will be in no doubt that these global changes to Earth were caused by their own species. Today we can say when those changes began and why. The Anthropocene probably began when species jumped continents, starting when the Old World met the New. We humans are now a geological power in our own right -- as Earth-changing as a meteorite strike."

He added: "Historically, the collision of the Old and New Worlds marks the beginning of the modern world. Many historians regard agricultural imports into Europe from the vast new lands of the Americas, alongside the availability of coal, as the two essential precursors of the Industrial Revolution, which in turn unleashed further waves of global environmental changes. Geologically, this boundary also marks Earth's last globally synchronous cool moment before the onset of the long-term global warmth of the Anthropocene."

The authors also considered the merits of dating the Anthropocene to 1964, which saw a peak in radioactive fallout following nuclear weapons testing. This marker is seen in many geological deposits, and by the 1960s human impact on the Earth was large. However, the researchers note that while nuclear war could dramatically alter Earth, so far it has not. While the fallout from nuclear bomb tests is a very good marker, the testing of nuclear weapons has not been -- in geological terms -- an Earth-changing event.

The beginning of the Industrial Revolution, in the late 18th century, has most commonly been suggested as the start of the Anthropocene. This linked a clear turning point in human history, and the rise of atmospheric carbon dioxide from fossil fuel use is a long-term global environmental change of critical importance. However, the researchers did not find a golden spike at that time because most effects were local, while the global exponential rise in carbon dioxide was too smooth an increase to form a precisely dated marker.

The authors' new paper ends by highlighting some implications of formally defining the Anthropocene.

Co-author, geologist Professor Mark Maslin (UCL Geography) said: "A more wide-spread recognition that human actions are driving far-reaching changes to the life-supporting infrastructure of Earth will have implications for our philosophical, social, economic and political views of our environment. But we should not despair, because the power that humans wield is unlike any other force of nature, it is reflexive and therefore can be used, withdrawn or modified. The first stage of solving our damaging relationship with our environment is recognising it."

An official decision on whether to formally recognise the Anthropocene, including when it began, will be initiated by a recommendation of the Anthropocene Working Group of the Subcommission of Quaternary Stratigraphy, due in 2016.

Source: University College London [March 11, 2015]

Scientists studying the Chicxulub crater have shown how large asteroid impacts deform rocks in a way that may produce habitats for early life.

Around 65 million years ago a massive asteroid crashed into the Gulf of Mexico causing an impact so huge that the blast and subsequent knock-on effects wiped out around 75 per cent of all life on Earth, including most of the dinosaurs. This is known as the Chicxulub impact.

In April and May 2016, an international team of scientists undertook an offshore expedition and drilled into part of the Chicxulub impact crater. Their mission was to retrieve samples from the rocky inner ridges of the crater -- known as the 'peak ring' -- drilling 506 to 1335 metres below the modern day sea floor to understand more about the ancient cataclysmic event.

Now, the researchers have carried out the first analysis of the core samples. They found that the impact millions of years ago deformed the peak ring rocks in such a way that it made them more porous, and less dense, than any models had previously predicted.

Porous rocks provide niches for simple organisms to take hold, and there would also be nutrients available in the pores, from circulating water that would have been heated inside the Earth's crust. Early Earth was constantly bombarded by asteroids, and the team have inferred that this bombardment must have also created other rocks with similar physical properties. This may partly explain how life took hold on Earth.

The study, which is published today in the >journal Science, also confirmed a model for how peak rings were formed in the Chicxulub crater, and how peak rings may be formed in craters on other planetary bodies.

The team's new work has confirmed that the asteroid, which created the Chicxulub crater, hit the Earth's surface with such a force that it pushed rocks, which at that time were ten kilometres beneath the surface, farther downwards and then outwards. These rocks then moved inwards again towards the impact zone and then up to the surface, before collapsing downwards and outwards again to form the peak ring. In total they moved an approximate total distance of 30 kilometres in a matter of a few minutes.

Professor Joanna Morgan, lead author of the study from the Department of Earth Science and Engineering, said: "It is hard to believe that the same forces that destroyed the dinosaurs may have also played a part, much earlier on in Earth's history, in providing the first refuges for early life on the planet. We are hoping that further analyses of the core samples will provide more insights into how life can exist in these subterranean environments."

The next steps will see the team acquiring a suite of detailed measurements from the recovered core samples to refine their numerical simulations. Ultimately, the team are looking for evidence of modern and ancient life in the peak-ring rocks. They also want to learn more about the first sediments that were deposited on top of the peak ring, which could tell the researchers if they were deposited by a giant tsunami, and provide them with insights into how life recovered, and when life actually returned to this sterilised zone after the impact.

Source: Imperial College London [November 17, 2016]

Scientists analysing samples from Mars' surface have so far not conclusively detected organic compounds that are indigenous to Mars, which would be indicators of past or present life. The inconclusive results mean that researchers are now suggesting that a good place to find these organic compounds would be deep underground – from rocks that have been blasted to the surface by meteor impacts. This is because such rocks have been sheltered from the Sun's harmful radiation and from chemical processes on the surface that would degrade organic remains.

Now, a team of scientists from Imperial College London and the University of Edinburgh has replicated meteorite blasts in the lab. The aim of the study was to see if organic compounds encased in rock could survive the extreme conditions associated with them being blasted to the surface of Mars by meteorites.  The study, >published in Scientific Reports, suggests that rocks excavated through meteorite impacts may incorrectly suggest a lifeless early Mars, even if indicators of life were originally present.

In the study the team replicated blast impacts of meteorites of around 10 metres in size. The researchers found that the types of organic compounds found in microbial and algal life - long chain hydrocarbon-dominated matter- were destroyed by the pressures of impact. However, the types of organic compounds found in plant matter – dominated by aromatic hydrocarbons - underwent some chemical changes, but remained relatively resistant to impact pressures. Meteorites often contain organic matter not created by life, which have some similarities in their organic chemistry to land plants. The team infer that they also should also be resistant to blast impacts.

Their study could help future missions to Mars determine the best locations and types of blast excavated rocks to examine to find signs of life. For example, it may be that meteorite impacts of a certain size may not destroy organic compounds or scientists may need to concentrate on rocks excavated from a certain depth.

Professor Mark Sephton, co-author of the research from the Department of Earth Science and Engineering at Imperial College London, said: "We've literally only scratched the surface of Mars in our search for life, but so far the results have been inconclusive. Rocks excavated through meteorite impacts provide scientists with another unique opportunity to explore for signs of life, without having to resort to complicated drilling missions. Our study is showing us is that we may need to be nuanced in our approach to the rocks we choose to analyse."

Dr Wren Montgomery, co-author of the study from the Department of Earth Science and Engineering, added: "The study is helping us to see that when organic matter is observed on Mars, no matter where, it must be considered whether the sample could have been affected by the pressures associated with blast impacts. We still need to do more work to understand what factors may play an important role in protecting organic compounds from these blast impacts. However, we think some of the factors may include the depths at which the rock records are buried and the angles at which meteorites hit the Martian surface."

Previous in situ analyses of the Martian terrain have found inconclusive evidence for the existence organic compounds – so far only finding chlorinated organic matter. The issue for scientists has been that it is not easy to look at simple chlorine-containing organic molecules and determine the origin of the organic compound components.

NASA's Viking landers in 1976 detected chlorine-containing organic compounds, but they were thought to be chemical left-overs from cleaning procedures of Viking's equipment before it left Earth. Later, the Phoenix Mission in 2008 discovered chlorine-containing minerals on the Martian surface, but no organic compounds. In 2012 the Mars Science Laboratory Mission detected chlorinated organic matter, but they thought that the analysis process, which involved heating chlorine containing minerals and carbonaceous material together, was producing chlorine-containing organic compounds. Working out whether the source of the carbon found on Mars was carried once again from Earth or was indigenous to Mars remains frustratingly difficult for scientists.

The team carried out their research by subjecting the different types of organic matter to extreme pressure and temperature in a piston cylinder device. They then did a chemical analysis using pyrolysis-gas chromatography mass spectrometry.

The next steps will see the team investigating a broader range of pressures and temperatures, which would help them understand the likely effects of a greater range of meteorite impacts. This would enable them to identify the specific conditions under which organic material may escape the destructive effects of blasts – even when excavated from deep underground by violent events. This could help future Mars missions further refine the types and locations of rocks that they can analyse for signs of past or present life.

Author: Colin Smith | Source: Imperial College London [August 08, 2016]

The Museo Civico Archeologico is hosting Egypt. Millennia of Splendour. Beneath the two towers, the splendour of a civilisation that lasted thousands of years and has always fascinated the entire world, has sprung back to life: the Egypt of the pyramids, pharaohs and multiform gods, but also that of sensational discoveries, captivating archaeology, passionate collecting and rigorous scholarship.

The exhibition ‘Egypt’, which is being held at the Museo Civico Archeologico in Bologna, is not just an exposition of high visual and scientific impact, but also an unprecedented international enterprise: the Egyptian collection of the National Museum of Antiquities in Leiden, Netherlands – among the top ten in the world – and that of the Bologna museum – among the most important in Italy for the quantity, quality and state of conservation of its collections – have been brought together in an exhibition space measuring around 1,700 metres, filled with art and history.

500 finds, dating from the Pre-Dynastic Period to the Roman Period, gave been brought from the Netherlands to the Bologna museum. And, together with the masterpieces from Leiden and Bologna, the exhibition also includes important loans from the Museo Egizio in Turin and the Museo Egizio in Florence, creating a network of the most important Italian museums.

For the first time, the masterpieces of the two collections are being displayed side by side, including the Stele of Aku (Twelfth–Thirteenth Dynasty, 1976–1648 BC), the ‘major domo of the divine offering’, with a prayer describing the otherworldly existence of the deceased in a tripartite world divided into sky, earth and the beyond; gold items attributed to General Djehuty, who led the Egyptian troops to victory in the Near East for the great conqueror Pharaoh Thutmose III (1479–1425 BC); the statues of Maya, superintendent of the royal treasury of Tutankhamen, and Merit, a chantress of the god Amun, (Eighteenth Dynasty, reigns of Tutankhamen and Horemheb, 1333–1292 BC), the most important masterpieces in the National Museum of Antiquities in Leiden have left the Netherlands for the first time for the Bologna exhibition; and, among the numerous objects attesting to the refined lifestyle of the most wealthy Egyptians, a Mirror Handle (1292 BC) in the shape of a young woman holding a small bird in her hand.

Lastly, for the first time 200 years after the discovery of his tomb in Saqqara, the exhibition offers the unique and once-in-a-lifetime opportunity to see the important Reliefs of Horemheb reunited: Horemheb was the head commander of the Egyptian army during the reign of Tutankhamen, then rising to become the final sovereign of the Eighteenth Dynasty, from 1319 to 1292 BC and the reliefs are divided between the collections in Leiden, Bologna and Florence.

Thousands of years of the history of a unique civilisation revealed in a major exhibition that brings together masterpieces from important world collections and tells of the pyramids and pharaohs, the great captains and priests, the gods and other divinities, and the people that made Egyptian history and that, thanks to discoveries, archaeology and collecting, never stop enchanting, revealing, intriguing, fascinating and charming generation after generation.

The Seven Exhibition Sections

The Pre-Dynastic and Archaic Periods – At the Origins of History: The transition from raw material to form, from the oral tradition to the written one and from prehistory to history was a fundamental moment for Egyptian civilisation. The Leiden collection is rich in materials documenting the central role played by nature during this long cultural and artistic evolution.

The exhibition opens with a selection of these objects, which are strikingly modern in style, including a vase from the Naqada IID Period (named for a site in Upper Egypt and datable between 3375 and 3325 BC) decorated with ostriches, hills and water motifs. The scene depicted on this vase takes us back to an Egypt characterised by a flourishing landscape later changed over time by climatic changes. Ostriches, here painted red, along with elephants, crocodiles, rhinoceros and other wild animals were common in the Nile region at the time.

The Old Kingdom – A Political/Religious Model Destined for Success and its Weaknesses: The historic period of the Old Kingdom (from the Third to the Sixth Dynasty, roughly between 2700 and 2192 BC) is known for the pyramids and for the consolidation of a bureaucracy at the apex of which stood an absolute sovereign, considered a god on earth and lord of all of Egypt.

This definition of State and its worldly and otherworldly rules, which were highly elitist, are well documented by funerary objects, of which the Leiden museum has a particularly rich collection, including a calcite (alabaster) table for offerings.

Offerings to the deceased were a fundamental part of the funerary ritual, ensuring life after death. The uniqueness of this table, which belonged to a high state official named Defdj, lies in its circular shape, which was unusual, as well as the repetition of the concept of the offering as indicated by the inscription, the sculpted receptacles and, most importantly, the central depiction corresponding to the hieroglyph hotep (offering), or a table upon which one places a loaf of bread.

The Middle Kingdom – The God Osiris and a New Perspective on Life in the Afterworld: The end of the Old Kingdom and the period of political breakdown that followed it led to major changes in Egyptian society, within which the individual had greater responsibility for his own destiny, including in the afterworld. Any Egyptian with the means to build a tomb complete with a sufficient funerary assemblage could now aspire to eternal life. The god Osiris, lord of the afterworld, became Egypt’s most popular divinity.

Many steles now in Leiden and Bologna came from his temple in Abydos, one of Egypt’s most important cult centres. Among them is that of Aku, major domo of the divine offering, who dedicated the stele to Min-Hor-nekht, the form of the ithyphallic god Min worshipped in the city of Abydos. Aku’s prayer to the god describes an otherworldly existence in a tripartite world: the sky, where the deceased were transfigured into stars, the earth, where the tomb was the fundamental point of passage from life to death, and the beyond, where Osiris granted the deceased eternal life.

From the Middle to the New Kingdom – Territorial Control at Home and Abroad: The defeat of the Hyksos, ‘princes from foreign lands’ who invaded and governed northern Egypt for a few generations, marked the beginning of the New Kingdom. An extremely aggressive foreign policy enriched Egypt, and this was one of its periods of greatest splendour. The social class of professional warriors rose to the top of the state hierarchy and spawned a number of ruling dynasties.

The wealth and prestige of these soldiers was also expressed in the production of sophisticated objects, including the gold items attributed to Djehuty, a general under the pharaoh Thutmose III. The Egyptian goldsmith’s art has survived in works of high artistic and economic value, an example being the pectoral element on view in the exhibition.

This piece is a sophisticated exemplar attributed to the tomb of General Djehuty, the man to whom the sovereign Thutmose III entrusted control of his foreign territories. Representing a blue lotus flower, a symbol of rebirth and regeneration, it must have served as the central element of an elaborate pectoral. The scroll engraved on the back suggests that the piece was given personally by Thutmose III.

The Saqqara Necropolis of the New Kingdom: The Leiden and Bologna museums can be considered ‘twins’ in a certain sense, since they house two important groups of antiquities from Saqqara, one of the necropolises of the city of Memphis. During the New Kingdom, this early Egyptian capital returned to its role as a strategic centre for the expansionist policy of the sovereigns of the Eighteenth Dynasty.

This is seen in the funerary monuments of high state officials who held administrative, religious and military roles, including the tombs of the superintendent of Tutankhamen’s royal treasury, Maya, and his wife, Merit, chantress of Amun, and that of Horemheb, head commander of Tutankhamen’s army and the pharaoh’s crown prince.

The statues of Maya and Merit arrived in the Netherlands in 1829 as part of the collection of Giovanni d’Anastasi. More than a century and a half would pass before, in 1986, a British/Dutch archaeological expedition identified the tomb from which they came, southeast of the pyramid of Djoser at Saqqara. These statues, which are the greatest masterpieces in the collection of the National Museum of Antiquities in Leiden, left the Dutch museum for the first time to be displayed in the exhibition.

It should be noted that, when the Egypt Exploration Society of London and the National Museum of Antiquities in Leiden began excavation work southeast of the Djoser pyramid in 1975, the goal was to find the tomb of Maya and Merit. It was therefore a great surprise when they instead discovered the burial of General Horemheb, who had capped off his stunning career by becoming the last sovereign of the Eighteenth Dynasty.

His tomb, which has a temple structure, is characterised by a pylon entrance, three large courts and three cult chapels facing onto the innermost court, which has a peristyle structure. This court is where most of the reliefs preserved in Leiden and Bologna were found, narrating Horemheb’s most important military feats against the populations bordering Egypt: the Asians, Libyans and Nubians.

The New Kingdom – Prosperity after the Conquest: Refined furnishings, musical instruments, table games and jewellery: these are just a few of the luxury goods attesting to the widespread prosperity enjoyed in Egypt as a result of the expansionist policy of the sovereigns of the New Kingdom. Through these sophisticated objects, it is possible to conjure up moments of everyday life, imagining what it was like living inside a royal palace or the residence of a high official. One example in the exhibition is a mirror handle in the graceful, sensual shape of a young women holding a small bird in her hand.

Egypt in the First Millennium: In the first millennium BC, Egypt was characterised by the increasingly clear weakness of its central power to the advantage of local governors who gave themselves the role of ruling dynasts. The loss of political and territorial power weakened Egypt’s defence capacity at its borders, opening the way for Nubian, Assyrian and Persian invasions. The temples remained strong centres of power, and managed a sizeable portion of the economy and the transmission of knowledge, taking on the role of a political intermediary between the ruling power and the devout populace.

Many of the masterpieces on view in the exhibition were part of the funerary assemblages of priests and came from important temple areas. Among them is the sarcophagus of Peftjauneith, which represents the likeness of the god Osiris, wrapped in a linen shroud and with a green face evoking the concept of rebirth. The refined decoration of this sarcophagus confirms the high rank of its owner (the superintendent of the possessions of a temple in Lower Egypt) in the temple sphere. Of particular note is the interior scene of the sky goddess Nut swallowing the sun every evening (to the west) to then give birth to it in the morning (to the east).

Alexander the Great’s conquest of Egypt in 332 BC ended the ‘pharaonic’ phase of Egyptian history. The period of Greek domination was begun by his successors, the Ptolemies, the last of whom was the renowned Cleopatra VII.

The golden decline of Egypt would continue for many more centuries, beyond the Roman conquest in 31 BC up to Arab domination in the sixth century AD.

The dialogue between old and new, local and foreign that distinguished the Greco-Roman period brought a return to high artistic achievements, including the celebrated Fayum portraits, exquisite examples of which from the Leiden collection are on view in the exhibition

Source: Museo Civico Archeologico in Bologna [October 19, 2015]

A new study published by PeerJ documents injuries inflicted in life and death to a large tyrannosaurine dinosaur. The paper shows that the skull of a genus of tyrannosaur called Daspletosaurus suffered numerous injuries during life, at least some of which were likely inflicted by another Daspletosaurus. It was also bitten after death in an apparent event of scavenging by another tyrannosaur. Thus there's evidence of combat between two large carnivores as well as one feeding on another after death.

Daspletosaurus was a large carnivore that lived in Canada and was only a little smaller than its more famous cousin Tyrannosaurus. Like other tyrannosaurs it was most likely both an active predator and scavenger. The individual in question, from Alberta Canada, was not fully grown and would be considered a 'sub-adult' in dinosaur terms (approximately equivalent to an older teenager in human terms). It would have been just under 6 m long and around 500 kg when it died.

Researchers found numerous injuries on the skull that occurred during life. Although not all of them can be attributed to bites, several are close in shape to the teeth of tyrannosaurs. In particular one bite to the back of the head had broken off part of the skull and left a circular tooth-shaped puncture though the bone. The fact that alterations to the bone's surface indicate healing means that these injuries were not fatal and the animal lived for some time after they were inflicted.

Lead author Dr David Hone from Queen Mary, University of London said "This animal clearly had a tough life suffering numerous injuries across the head including some that must have been quite nasty. The most likely candidate to have done this is another member of the same species, suggesting some serious fights between these animals during their lives."

There is no evidence that the animal died at the hands (or mouth) of another tyrannosaur. However, the preservation of the skull and other bones, and damage to the jaw bones show that after the specimen began to decay, a large tyrannosaur (possibly of the same species) bit into the animal and presumably ate at least part of it.

Combat between large carnivorous dinosaurs is already known and there is already evidence for cannibalism in various groups, including tyrannosaurs. This is however an apparently unique record with evidence of both pre- and post-mortem injuries to a single individual.

Source: PeerJ [April 09, 2015]

Hot vents on the seabed could have spontaneously produced the organic molecules necessary for life, according to new research by UCL chemists. The study shows how the surfaces of mineral particles inside hydrothermal vents have similar chemical properties to enzymes, the biological molecules that govern chemical reactions in living organisms. This means that vents are able to create simple carbon-based molecules, such as methanol and formic acid, out of the dissolved CO2 in the water.

The discovery, published in the journal Chemical Communications, explains how some of the key building blocks for organic chemistry were already being formed in nature before life emerged - and may have played a role in the emergence of the first life forms. It also has potential practical applications, showing how products such as plastics and fuels could be synthesised from CO2 rather than oil.

"There is a lot of speculation that hydrothermal vents could be the location where life on Earth began," says Nora de Leeuw, who heads the team. "There is a lot of CO2 dissolved in the water, which could provide the carbon that the chemistry of living organisms is based on, and there is plenty of energy, because the water is hot and turbulent. What our research proves is that these vents also have the chemical properties that encourage these molecules to recombine into molecules usually associated with living organisms."

The team combined laboratory experiments with supercomputer simulations to investigate the conditions under which the mineral particles would catalyse the conversion of CO2 into organic molecules. The experiments replicated the conditions present in deep sea vents, where hot and slightly alkaline water rich in dissolved CO2 passes over the mineral greigite (Fe3S4), located on the inside surfaces of the vents. These experiments hinted at the chemical processes that were underway. The simulations, which were run on UCL's Legion supercomputer and HECToR (the UK national supercomputing service), provided a molecule-by-molecule view of how the CO2 and greigite interacted, helping to make sense of what was being observed in the experiments. The computing power and programming expertise to accurately simulate the behaviour of individual molecules in this way has only become available in the past decade.

"We found that the surfaces and crystal structures inside these vents act as catalysts, encouraging chemical changes in the material that settles on them," says Nathan Hollingsworth, a co-author of the study. "They behave much like enzymes do in living organisms, breaking down the bonds between carbon and oxygen atoms. This lets them combine with water to produce formic acid, acetic acid, methanol and pyruvic acid. Once you have simple carbon-based chemicals such as these, it opens the door to more complex carbon-based chemistry."

Theories about the emergence of life suggest that increasingly complex carbon-based chemistry led to self-replicating molecules - and, eventually, the appearance of the first cellular life forms. This research shows how one of the first steps in this journey may have occurred. It is proof that simple organic molecules can be synthesised in nature without living organisms being present. It also confirms that hydrothermal vents are a plausible location for at least part of this process to have occurred.

The study could also have a practical applications, as it provides a method for creating carbon-based chemicals out of CO2, without the need for extreme heat or pressure. This could, in the long term, replace oil as the raw material for products such as plastics, fertilisers and fuels.

This study shows, albeit on a very small scale, that such products, which are currently produced from non-renewable raw materials, can be produced by more environmentally friendly means. If the process can be scaled up to commercially viable scales, it would not only save oil, but use up CO2 - a greenhouse gas - as a raw material.

Source: University College London [April 27, 2015]

Early Earth was an inhospitable place where the planet was often bombarded by comets and other large astrophysical bodies.

Some of those comets contained complex prebiotic materials, such as amino acids and peptides (chains of amino acids), which are some of the most basic building blocks of life on Earth.

“The survivability of these compounds under impact conditions is mostly unknown,” said Lawrence Livermore’s Nir Goldman, who recently received a NASA grant to continue his astrobiology research. “Our research hopes to answer these questions and give an indication for what types of potentially life-building compounds would be produced under these conditions.”

Basically, Goldman is trying to figure out if life on Earth really did come from out of this world.

Goldman’s early research found that the impact of icy comets crashing into Earth billions of years ago could have produced a variety of small prebiotic or life-building compounds. His work using quantum simulations predicted that the simple molecules found in comets (such as water, ammonia, methanol and carbon dioxide) could have supplied the raw materials, and the impact with early Earth would have yielded an abundant supply of energy to drive the synthesis of compounds like protein forming amino acids. In later work, researchers from Imperial College in London and University of Kent conducted a series of experiments very similar to Goldman’s simulations in which a projectile was fired using a light gas gun into a typical cometary ice mixture. The result: Several different types of amino acids formed.

“Impact events could have not only delivered prebiotic precursors to the primitive planet, but the sudden increase in pressure and temperature from the impact itself was likely a driving factor in synthesizing their assembly into these primary structures,” Goldman said.

Specifically, this new $500,000 grant will fund quantum simulation studies to understand aqueous mixtures of pre-formed amino acids under impact conditions. Goldman’s current efforts will extend his previous work by looking at one step higher in complexity, where extreme pressures and temperatures from impact could induce the formation of more intricate chemical structures like peptide chains or simple proteins.

“Large astrophysical bodies such as comets likely already contain more complex prebiotic materials, like amino acids. It’s possible that pre-existing amino acids would have experienced additional impacts during periods of heavy bombardment on early Earth,” Goldman said. “Our quantum simulations hope to help answer these questions, and to give an indication as to what set of thermodynamic conditions promotes their assembly into larger structures.”

How and when prebiotic organic material appeared on early Earth has been debated for close to 60 years, starting with the seminal Miller-Urey experiments, which showed that amino acids could be produced in aqueous mixtures subjected to electrical discharges, simulating lightning on early Earth.

Large bodies from space are carriers of prebiotic materials. Previous analysis of dust samples from comet Wild 2 has shown the presence of the amino acid glycine in the captured material. In addition, dipeptides (i.e., an amino acid dimer) likely exist in interstellar ices. Assuming survival upon delivery to Earth, these could have acted as catalysts in the formation of a number of prebiotic compounds, including sugars and enzymes.

“Our predictions will help spur future collaboration with experimental groups to characterize the synthesis of primary biomaterials due to exposure to extreme pressures and temperatures,” Goldman said.

Source: Lawrence Livermore National Laboratory [July 07, 2015]

Planet Earth may contain millions fewer species than previously thought and estimates are converging, according to research led by Griffith University.

In a paper published by the journal Proceedings of the National Academy of Sciences (PNAS), Professor Nigel Stork of Griffith’s Environmental Futures Research Institute reveals findings that narrow global species estimates for beetles, insects and terrestrial arthropods.

The research features an entirely new method of species calculation derived from samples of beetles from the comprehensive collection at London’s Natural History Museum.

“It has been said we don’t know to the nearest order of magnitude just how many species with which we share the planet. Some say it could be as low as two million; others suggest up to 100 million,” says Professor Stork.

“By narrowing down how many species exist within the largest group – the insects and other arthropods — we are now in a position to try to improve estimates for all species, including plants, fungi and vertebrates.

“Understanding how many species there are and how many there might have been is critical to understanding how much humans have impacted biodiversity and whether we are at the start of, or even in the middle of, an extinction crisis.”

About 25 per cent of all species that have been described are beetles. However, when combined with other insects the figure climbs to more than half of all described and named species on Earth.

New method of estimation

For this reason, Professor Stork and his colleagues focused on asking how many species of beetles and insects there actually are, in the process applying a new method of estimation arising from a tendency for larger species of British beetles to be described before smaller species.

“Because of the global spread of major beetle lineages, we made the assumption that the size distribution of the very well known British beetles might be similar to that of beetles worldwide,” says Professor Stork.

“So, if we could get a measurement of the body sizes of the beetles from around the world, we might be able to plot where these fitted in time against the British beetles.”

After measuring a sample from the Natural History Museum’s worldwide collection of beetles, Professor Stork compared the mean body size with the changing body sizes of British beetles to reveal that roughly 10 per cent of the world’s beetles have been named and described.

This figure sheds intriguing light on previous estimates of global species richness.

In the 1980s, there were just two methods of estimating species. In the case of beetles, these gave a mean of 17.5 million species and a range of 4.9-40.7 million. For all terrestrial arthropods, the mean was 36.8 million and a range of 7-80 million.

However, the new research shows that four current methods of estimation – dating from 2001 onwards — suggest much lower figures, namely a mean of 1.5 million for beetles (range 0.9-2.1 million) and 6.8 million for terrestrial arthropods (range 5.9-7.8 million).

“While all methods of estimating global species richness make assumptions, what is important here is that four largely unrelated methods, including the new body size method, produce similar estimates,” says Professor Stork.

“With estimates converging in this way, this suggests we are closer to finding the real numbers than before.

“It also means we can improve regional species richness. For Australian fauna and flora, for example, we should be able to make better estimates of just how many species there are and which groups need more taxonomic attention.”

Diversity of life

Professor Ian Owens, Director of Science at the Natural History Museum, says this research is a great example of how natural history collections support high-impact scientific research that addresses challenging questions such as the diversity of life.

“The Natural History Museum’s beetle collection is one of the most important and extensive in the world, so I’m delighted that it has played such a fundamental part in this study that uses a novel approach to estimating how many species of beetle exist,” says Professor Owens.

“The results are very exciting and are a big step forward to establishing a baseline for biodiversity.”

Meanwhile, co-author of the PNAS paper — the University of Melbourne’s Associate Professor Andrew Hamilton – says efforts to come up with new or modified ways of resolving how many species exist are beginning to prove fruitful.

Professor Stork says the research has important conservation ramifications.

“Success in planning for conservation and adopting remedial management actions can only be achieved if we know what species there are, how many need protection and where,” he says. “Otherwise, we have no baseline against which to measure our successes.

“Furthermore, it is arguably not only the final number of species that is important, but what we discover about biodiversity in the process.

“The degree to which we can or cannot accurately estimate the number of species or the scale of organismal diversity on Earth is a measure of our ignorance in understanding the ecological and evolutionary forces that create and maintain the biodiversity on our planet.

“Attacking this question also drives scientific enquiry and is of public interest. Society expects science to know what species exist on Earth, as it expects science to discover nuclear particles and molecules.

“These discoveries open doors to more utilitarian interests.”

Source: Griffith University [June 02, 2015]

Opening April 27 (and running until July 24, 2016) at New York’s Metropolitan Museum of Art, the landmark international loan exhibition Court and Cosmos: The Great Age of the Seljuqs features spectacular works of art created in the 11th through 13th century from Turkmenistan to the Mediterranean.

One of the most productive periods in the history of the region from Iran to Anatolia (in modern Turkey) corresponds to the rule of the Seljuqs and their immediate successors, from 1038 to 1307.

The Seljuqs were a Turkic dynasty of Central Asian nomadic origin that established a vast, but decentralized and relatively short-lived, empire in West Asia (present-day Turkmenistan, Iran, Iraq, Syria, and Turkey).

Under Seljuq rule, the exchange and synthesis of diverse traditions—including Turkmen, Perso-Arabo-Islamic, Byzantine, Armenian, Crusader, and other Christian cultures—accompanied economic prosperity, advances in science and technology, and a great flowering of culture within the realm.

Approximately 270 objects—including ceramics, glass, stucco, works on paper, woodwork, textiles, and metalwork—from American, European, and Middle Eastern public and private collections are shown. Many of the institutions have never lent works from their collections before. Among the highlights are a dozen important loans from Turkmenistan—the exhibition marks the first time that Turkmenistan as an independent country has permitted an extended loan of a group of historical objects to a museum in the United States.

Under the Great Seljuqs of Iran, the middle class prospered, spurring arts patronage, technological advancements, and a market for luxury goods. In contrast, in Anatolia, Syria, and the Jazira (northwestern Iraq, northeastern Syria, and southeastern Turkey)—which were controlled by the Seljuq successor dynasties (Rum Seljuqs, Artuqids, and Zangids)—art was produced under royal patronage, and Islamic iconography was introduced to a predominantly Christian area.

Furthermore, a number of artists had immigrated to the region from Iran in response to the Mongol conquest in 1220. Because patrons, consumers, and artists came from diverse cultural, religious, and artistic backgrounds, distinctive arts were produced and flourished in the western parts of the Seljuq realm.

Exhibition Overview

Arranged thematically, the exhibition opens with a display of artifacts that name the Seljuq sultans and members of the ruling elite. In Central Asia and Iran, inscriptions appeared on coins and architecture. Stucco reliefs representing royal guards, amirs, and courtiers serve to evoke the courts of the Great Seljuq rulers whose names did not appear on objects.

In Anatolia, Syria, and the Jazira, names of Seljuq successor rulers and images appeared on a range of objects. Here, the famous 12th-century cloisonné dish bearing the name of Rukn al-Dawla Dawud, a leader of the Artuqids, is featured.

In the second section, the courtly environment and activities associated with the sultans and their courtiers appear on stucco reliefs, ceramics, metalwork, and other media. While depictions of the Seljuq elite on these works were not intended as actual portraits, the distinctive Central Asian facial type was a standard of beauty under Seljuq rule.

The earliest extant manuscript of the Shahnama (Book of Kings)—the Persian national epic—created in Anatolia in 1217 is a highlight of this section. Additionally, the remarkable Blacas ewer, with its myriad details of life connected to the court, is prominently exhibited.

The three centuries under Seljuq rule were also a period of inventions; and the many advances in science, medicine, and technology were reflected in the manuscripts, scientific instruments, and medical implements of the time. Pages from the early 13th-century illustrated manuscript The Book of Knowledge of Ingenious Mechanical Devices feature some of the fanciful inventions of the Muslim polymath and creative genius Ibn al-Razzaz al-Jazari, whose inventions ranged from clocks and water wheels to automata (robots).

Also noteworthy is an early Islamic astrolabe. (Among the many things that could be determined by means of this complex navigational instrument was the direction of Mecca, and hence the direction of prayer.) Also on view is an intricate pharmacy box with separate compartments for musk, camphor, and other ingredients typical of the medieval pharmacopoeia.

Seljuq art abounds with depictions of real, mythological, and hybrid animals on objects large and small. Animal combat was a favorite theme in Iranian art. The double-headed eagle was adopted as the standard of the Seljuq successor states in Anatolia and the Jazira. Harpies (composite creatures having the body of a bird and the face of a human) and sphinxes (beasts with the body of a lion, face of a human, and occasionally the wings of a bird) appear frequently.

The exquisite Vaso Vescovali—a lidded bowl engraved and inlaid with silver and decorated with complex astrological imagery—features eight personifications of planets on the lid along with the 12 signs of the zodiac and their associated planets on the base, within a profusion of other ornamentation.

The Seljuqs actively promoted Sunni Islam throughout their territory, building madrasas and mosques, and sponsoring the production of Qur’ans and other religious texts. A number of rare and beautifully ornamented examples of the book arts from the time of the Seljuqs are on view. In Syria, the Jazira, and Anatolia—where the majority of the local population, including some of the ruling elite, was Christian—artifacts bearing Christian iconography continued to be made. And a ritual vessel from Georgia, with a Hebrew inscription, attests to the presence of Jewish populations as well. The same artists often served various religious communities. Hence, the styles and artistic traditions of one group merged with those of another.

The sixth and final section of the exhibition focuses on the funerary arts. A variety of tomb markers, cenotaphs, funerary furniture, and patterned textiles discovered in Seljuq tombs are shown. In a proper Muslim burial, the deceased is wrapped in two or three sheets of plain white cloth; the presence of expensive textiles in a funerary context indicates that popular customs and official practice differed significantly.

The exhibition is made possible by the NoRuz at The Met Fund and the Iranian-American Community.

Source: Metropolitan Museum, New York [April 30, 2016]

Various specimens of Africa’s earliest coelacanth have been found in a 360 million year-old fossil estuary near Grahamstown, in South Africa’s Eastern Cape.

More than 30 complete specimens of the new fossil species, Serenichthys kowiensis, were collected from the famous Late Devonian aged Waterloo Farm locality, by palaeontologist Dr Robert Gess and described by him in collaboration with Professor Michael Coates of the University of Chicago.

Gess did the research whilst he was completing his PhD at the Evolutionary Studies Institute at the University of the Witwatersrand. An article describing the new species will be published in the in the prestigious Zoological Journal of the Linnean Society of London on Monday, 21 August.

“Remarkably, all of the delicate whole fish impressions represent juveniles. This suggests that Serenichthys was using a shallow, waterweed-filled embayment of the estuary as a nursery, as many fish do today,” says Gess.

The fossils come from black shales originally disturbed by road works at Waterloo Farm. These shales are the petrified compacted remains of mud, which was deposited in the quiet reaches of an estuary not unlike some of those along the Eastern Cape coast today.

“This earliest known record of a coelacanth nursery foreshadows a much younger counterpart, known from the 300 million year old Mazon Creek beds of Illinois in the United States,” says Gess.

“This glimpse into the early life history of ancient coelacanths raises further questions about the life history of the modern coelacanth, Latimeria, which is known to bear live young, but whether they, too, are clustered in nurseries remains unknown,” explains Coates.

360 million years ago, Africa was part of the southern supercontinent Gondwana, made up of Africa, India, Australia, Antarctica and South America. At that time, the rocks of Waterloo Farm were forming along the shores of the semi-enclosed Agulhas Sea, not far from the South Pole.

Gess originally identified coelacanth remains from the locality whilst carrying out excavations at Waterloo Farm in the mid-1990s under the supervision of Dr Norton Hiller, of the Rhodes University Geology Department. These fossils were not, however, well enough preserved to be reconstructed and described. His painstaking excavation of tons of shale salvaged during subsequent roadworks has now shed light on dozens more specimens, a few of which are preserved in exquisite detail.

These were prepared under a microscope and have allowed the species to be reconstructed in minute detail. They prove to be a new genus and species.

Coelacanths are believed to have arisen during the Devonian Period (about 419.2 ± 3.2 million years ago), however only five species of reconstructable Devonian coelacanths have previously been described, in addition to a number of very fragmentary remains. None of these came from Africa, but rather from North America, Europe, China and Australia. The new species gives important additional information on the early evolution of coelacanths.

“According to our evolutionary analysis (conducted by Gess and Coates), it is the Devonian species that most closely resembles the line leading to modern coelacanths,” says Gess.

The new species was discovered a mere 100km from the mouth of the Chalumna River, off which the type specimen of Latimeria chalumnae (the first discovered modern coelacanth) was caught in 1938.

Furthermore, the Geology Department at Rhodes, where Gess was based when he found his first fossil coelacanth, is on the site of the former Chemistry Department where Latimeria was first described. In keeping with the naming of its living relative (after an Eastern Cape river), the species name of the new fossil form, kowiensis, is after the Kowie River which rises among the hills where it was found, and the genus name, Serenichthys, honours Serena Gess, who provided land for the storage of more than 70 tons of black shale rescued from roadworks for ongoing research – in which all the new material was found.

All specimens have been deposited in the palaeontological collection of the Albany Natural History Museum, in Grahamstown, Eastern Cape Province, South Africa.

Source: University of the Witwatersrand [September 21, 2015]

The copper used to make Ötzi’s axe blade did not come from the Alpine region as had previously been supposed, but from ore mined in southern Tuscany. Ötzi was probably not involved in working the metal himself, as the high levels of arsenic and copper found in his hair had, until now, led us to assume.

His murder over 5,000 years ago seems to have been brought about due to a personal conflict a few days before his demise, and the Iceman, despite his normal weight and active life-style, suffered from extensive vascular calcification.

Scientists from all over the world presented these and other new insights, at the 3rd Bolzano Mummy Congress. To celebrate the 25th anniversary of Ötzi’s discovery, the three days of the Congress, from 19th to 21st September, are all dedicated to the Iceman.

Since the Iceman came on the scene on 19th September 1991, he has not ceased to fascinate scientists from all over the world. No corpse has been more thoroughly investigated. “In terms of his significance for science, Ötzi is not simply an isolated mummy discovery. He could be seen as a typical European from earlier times and is precious for this reason alone,” explained the anthropologist Albert Zink from EURAC Research, the scientific leader of the congress.

“Ötzi is so well preserved as a glacier mummy and through this alone, he serves us researchers as a model for developing scientific methods which can then be used on other mummies,” said Zink.

“What concerns us most these days is to know who the Iceman was, what role he played in society and what happened to him in the last days of his life. Sophisticated procedures, now available to scientists, are continually supplying us with new evidence,” said Angelika Fleckinger, Director of the South Tyrol Museum of Archaeology which co-organised the Congress.

Links to Central Italy

One surprising new fact has been unearthed which concerns the most extraordinary item amongst Ötzi’s equipment – the valuable copper axe. In contrast to what had previously been presumed, the copper used in the blade does not derive from the Alpine region (researchers had suggested East or North Tyrol as the most likely provenance) but from Central Italy. Professor Gilberto Artioli‘s archaeometallurgy research group at the University of Padua has discovered that the metal had been obtained from ore mined in South Tuscany.

In order to determine its origin, Italian scientists took a tiny sample from the blade and compared the proportion of lead isotope – a kind of “finger print” of the ore deposits which remains unchanged in any objects subsequently made from the ore – with the corresponding data from numerous mineral deposits in Europe and the entire Mediterranean region. The result pointed unequivocally to South Tuscany.

“No one was prepared for this finding. We will commission further analyses in order to double-check these first results” stressed Angelika Fleckinger. If the original results are confirmed, this new evidence will give researchers some interesting food for thought.

Was Ötzi as a trader travelling possibly as far as the area around today’s Florence? What was the nature of the trading and cultural links with the south in those days? Did the exchange of goods also involve movements of the population? That is to say, did people from the south venture into the Alpine region and vice versa?

“This is a particularly exciting insight especially with respect to questions about population development”, explained Albert Zink.

Was he or was he not involved in smelting copper?

Another question long debated amongst the scientific community, is whether Ötzi was perhaps involved himself in the process of copper smelting. Scientists have advocated this thesis because raised arsenic and copper levels have been measured in the mummy’s hair, a fact which might possibly be explained, for example, by breathing in the smoke which is released when melting and pouring metal.

Geochemist Wolfgang Müller of Royal Holloway, University of London, who had already used isotope analysis to establish Ötzi’s South Tyrol origins, has now turned to this question once more. Using highly developed methods of analysis such as laser mass spectrometry and speciation analysis, Müller’s team examined not just hairs but also samples from Ötzi’s nails, skin and organs for possible heavy metal contamination.

His, so far still provisional, findings suggest that the hypothesis that Ötzi was involved in processing metal was premature. Müller did indeed find slightly raised arsenic values in the nail sample, but not in other tissue samples. Raised copper levels were only present at the extremities and this correlates with other change indicators, and thus it is doubtful if one can establish a heavy metal contamination for Ötzi’s actual life time: raised values might also be due to environmental influences over the 5,000 years since his death.

Radiological investigations with the latest CT equipment

A new computer tomography (CT) scan of the Iceman was undertaken by radiologists Paul Gostner and Patrizia Pernter in January 2013 in the Department of Radiology of Bozen-Bolzano Hospital. To do this they used a CT-scanner of the latest generation which, thanks to its large opening, allowed the doctors to run Ötzi rapidly through the machine from head to toe despite the way his arm is angled. In addition to the vascular calcification in the arteries of his stomach and legs which had already been known about, the superior image allowed doctors to spot three small areas of calcification near to the outflow tracts of the heart which had hitherto escaped their notice. This substantiates the earlier finding made by molecular biologists in EURAC that Ötzi had a strong genetic predisposition to cardiovascular diseases and that this was probably also the main reason for his general arteriosclerosis.

Investigations of a “profiler”

Ötzi was murdered. The arrow head discovered in 2001 in his left shoulder suggests this. But what were the circumstances surrounding the crime? In 2014 the South Tyrol Museum of Archaeology commissioned Chief Inspector Alexander Horn of the Munich Criminal Investigation Department to investigate the “Ötzi Murder Case” using the latest criminological methods.

Horn interrogated various “acquaintances” of the murder victim such as archaeologists from the museum who had been looking after Ötzi for years, or experts from forensic medicine, radiology and anthropology. Members of the project team also took part in an on-site inspection of the location in Schnals Valley in South Tyrol Italy where the body was found.

The results of this investigation were that Ötzi probably did not feel threatened shortly before his murder, because the situation at the Tisenjoch location where he was found indicates that he had been resting while enjoying a hearty meal. In the days prior to the murder he had incurred an injury to his right hand, probably as a result of defensive action during the course of a physical altercation. No further injuries could be found, and this might serve to indicate that he had not been defeated in this particular conflict.

The arrow shot, which was probably fatal, seems to have been launched from a great distance and took the victim by surprise, from which we may infer that it was an act of treachery. Further medical findings suggest that the victim fell and that the perpetrator used no further violence. The perpetrator probably did not wish to risk a physical altercation, but instead chose a long distance attack to kill the Iceman. As valuable objects such as the copper axe remained at the crime scene, theft can be excluded as the motive.

The reason for the offence is more likely to be found in some sort of personal conflict situation, in a previous hostile encounter – “a behavioural pattern which is prevalent even today in the bulk of murder crimes”, as Alexander Horn explained.

Source: Eurac Research [September 20, 2016]

The Museum of London today announced a ground-breaking research project to explore the effects of industrialisation on Londoners. The research hopes to uncover new clues about the very nature of disease and how it has affected people as Britain has moved into the age of industrialisation.

The research has been made possible by a City of London Archaeological Trust grant from a bequest made by the late Rosemary Green.

John Schofield, Secretary of the City of London Archaeological Trust, said: “The City of London Archaeological Trust is very happy that the Rosemary Green bequest is used to gather this cutting-edge data on the signs of industrialisation in the skeletal collections on the Museum of London.”

Leading the project is Jelena Bekvalac, based at the Museum of London’s Centre for Human Bioarcheology, along with her research team, Gaynor Western and Mark Farmer.

Jelena Bekvalac, said: “The most tangible evidence we have for the long-term consequences of the industrialisation process upon us is, quite simply, written in our bones. Using the very latest digital technology, we will examine the skeletal remains of over 1,000 adult men and women from industrial-era London in addition to a further 500 skeletons from the medieval metropolis.

“Modern health trends have seen a shift towards increasing life expectancy but we want to look again at what are often thought of as ‘man-made’ conditions like obesity and cancer. Given today’s more sedentary lifestyles, far removed from the physically active and natural existence of most of our forebears, there are some big questions about the origins of these diseases and how they relate to the modern environment.”

The research aims to address some of these questions by analysing diseases affecting the human skeleton. The museum will use the latest clinical techniques, including direct digital radiography, CT scanning and 3D modelling, to get a better understanding of what the bones tell us and to assess their change over time. The research aims to examine the influence of the industrial revolution, a pivotal catalyst in the formation of the modern age, on the changing nature of disease – from the medieval and post-medieval periods through to the present day.

The project offers an exciting opportunity to digitise some of London’s most important skeletal collections, while simultaneously telling a new story about the health of Londoners over time.

This work will culminate in the creation of an extensive new interactive digital resource that can be explored online. Jelena Bekvalac plans to make an immediate start on the digital scanning. She aims to publish her team’s findings as soon as possible and deliver a series of lectures about the work.

Source: Museum of London [April 24, 2015]

The Mesozoic played host to some of the most dangerous predators to ever swim the Earth's oceans. Among these, pliosaurs were lethal hunters, and some of the largest predators ever on this planet. They were the shorter-necked cousins of the plesiosaurs, which are often spoken of in reference to their superficial similarity to the Loch Ness Monster, which we're definitely not going to do here. Together, pliosaurs and plesiosaurs form a group known as Sauropterygia, which existed in the oceans from the Triassic right until the end of the Cretaceous, when they went extinct along with the non-avian dinosaurs and other vertebrate groups. This actually makes sauropterygians the longest living group of marine-adapted tetrapods (animals with four limbs), which is quite an impressive feat!

New discoveries show that perhaps this evolutionary success can be attributed to the ecological diversity that this group possessed, and in particular an ability to adapt to different feeding styles.

Valentin Fischer from the University of Oxford and an international team of researchers have discovered a new pliosaur from western Russia, named Makhaira rossica. The name dreives from the Latinized Ancient Greek word 'mákhaira', which describes a blade with a curved outline, as well as the Latin word 'rossica', which means Russian. The specimen comprises a fragmentary skeleton of a sub-adult animal, found within a series of limestone nodules along the banks of the Volga River.

Makhaira comes from a period in Earth's geological history, known as the earliest part of the Cretaceous, where our knowledge of vertebrate life is relatively poor due to the way in which fossils are differentially preserved through time. Sadly, this lack of knowledge means that our understanding of how faunas changed from the latest part of the Jurassic period into the first part of the Cretaceous is relatively poor compared to other important geological boundaries.

Analysis of the evolutionary placement of this new species places it as the most basal member of a group known as Brachaucheninae, which survived through the Cretaceous. However, the new species is different in being a little smaller than some of its more advanced relatives.

The weirdest feature of the new beasty has to be the teeth. The teeth occur in pairs, and have a trihedral form, meaning they had three peaks on each alveolus, and the edges of the teeth were adorned with wicked serrations. They were also very large, similar even to some teeth from theropod dinosaurs roaming the lands at the time!

The morphology of these teeth suggest that they were equipped just for one thing – devouring other large animals! This form of feeding is known as macrophagy, and was a common form of predation at the time for giant marine crocodyliforms (the ancestors of modern crocodiles) called metriorhynchids. Importantly, this feeding style previously seemed to have been lost in the early evolution of other brachauchenine pliosaurs, but now appears to have been present in at least one species from this group. This shows that Early Cretaceous pliosaurs were still well adapted to hypercarnivory, and retained a high feeding diversity at the beginning of the Cretaceous, and not lost from their Jurassic ancestors.

Recently, Alessandro Chiarenza, a colleague of mine at Imperial College London, reported on what appeared to be the oldest metriorhynchid remains currently known, from a fossil site in Sicily. Based on a single fossilised tooth from a period known as the Aptian, later on in the Cretaceous than when Makhaira was found, these remains extended the duration of metriorhynchids, and their eventual extinction, by several millions of years.

However, the morphology of the teeth of Makhaira wasn't known at the time of publishing the crocodyliform fossils, and it seems that it is actually impossible to distinguish between these and the teeth of some metriorhynchids. This means that the Sicilian tooth cannot be referred unequivocally to either a metriorhynchid or a pliosaur – the teeth of some species is just too similar to say for certain! What does this imply though? Well, it seems that the fate of metriorhynchids is still a mystery concealed by the fossil record, and is only something that future study of these fossils, their other monstrous counterparts, and discovery of new fossils can hope to solve!

The findings are published in the >Royal Society Open Science journal.

Author: Victoria Costello | Source: Public Library of Science [January 16, 2016]

New research has revealed that fewer than predicted planets may be capable of harboring life because their atmospheres keep them too hot.

When looking for planets that could harbor life, scientists look for planets in the 'habitable zones' around their stars - at the right distance from the stars to allow water to exist in liquid form. Traditionally, this search has focused on looking for planets orbiting stars like our Sun, in a similar way to Earth.

However, recent research has turned to small planets orbiting very close to stars called M dwarfs, or red dwarfs, which are much smaller and dimmer than the Sun. M dwarfs make up around 75 per cent of all the stars in our galaxy, and recent discoveries have suggested that many of them host planets, pushing the number of potentially habitable planets into the billions.

This month, both the TRAPPIST and Kepler planet-hunting telescopes have announced the discovery of multiple near-Earth-sized planets orbiting M dwarf stars, some within the habitable zones.

New research from Imperial College London and the Institute for Advanced Studies in Princeton, published in the >Monthly Notices of the Royal Astronomical Society, has revealed that although they orbit smaller and dimmer stars, many of these planets might still be too hot to be habitable.

The scientists suggest that some of the planets might still be habitable, but only those with a smaller mass than Earth, comparable to Venus or Mars.

Dr James Owen, Hubble Fellow and lead author of the study from the Institute for Advanced Studies in Princeton, said: "It was previously assumed that planets with masses similar to Earth would be habitable simply because they were in the 'habitable zone'. However, when you consider how these planets evolve over billions of years this assumption turns out not to be true."

It was known previously that many of these planets are born with thick atmospheres of hydrogen and helium, making up roughly one percent of the total planetary mass. In comparison, the Earth's atmosphere makes up only a millionth of its mass. The greenhouse effect of such a thick atmosphere would make the surface far too hot for liquid water, rendering the planets initially uninhabitable.

However, it was thought that over time, the strong X-ray and ultraviolet radiation from the parent M dwarf star would evaporate away most of this atmosphere, eventually making the planets potentially habitable.

The new analysis reveals that this is not the case. Instead, detailed computer simulations show that these thick hydrogen and helium envelopes cannot escape the gravity of planets that are similar to or larger in mass than the Earth, meaning that many of them are likely to retain their stifling atmospheres.

However, all is not lost, according to the researchers. While most of the M dwarf planets that are Earth-mass or heavier would retain thick atmospheres, smaller planets, comparable to Venus or Mars, could still lose them to evaporation.

Dr Subhanjoy Mohanty, the other study author from the Department of Physics at Imperial College London, said: "There are hints from recent exoplanet discoveries that relatively puny planets may be even more common around red dwarfs than Earth mass or larger ones, in which case there may indeed be a bonanza of potentially habitable planets whirling around these cool red stars."

Ongoing ground- and space-based searches, and new space missions to be launched in the near future, should provide a definitive answer to this question as well as other questions about the potential suitability of these planets for life.

Author: Hayley Dunning | Source: Imperial College London [May 26, 2016]

The diversity of mammals on Earth exploded straight after the dinosaur extinction event, according to UCL researchers. New analysis of the fossil record shows that placental mammals, the group that today includes nearly 5000 species including humans, became more varied in anatomy during the Paleocene epoch - the 10 million years immediately following the event.

Senior author, Dr Anjali Goswami (UCL Genetics, Evolution & Environment), said: "When dinosaurs went extinct, a lot of competitors and predators of mammals disappeared, meaning that a great deal of the pressure limiting what mammals could do ecologically was removed. They clearly took advantage of that opportunity, as we can see by their rapid increases in body size and ecological diversity. Mammals evolved a greater variety of forms in the first few million years after the dinosaurs went extinct than in the previous 160 million years of mammal evolution under the rule of dinosaurs."

The Natural Environment Research Council-funded research, published today in the Biological Journal of the Linnean Society, studied the early evolution of placental mammals, the group including elephants, sloths, cats, dolphins and humans. The scientists gained a deeper understanding of how the diversity of the mammals that roamed the Earth before and after the dinosaur extinction changed as a result of that event.

Placental mammal fossils from this period have been previously overlooked as they were hard to place in the mammal tree of life because they lack many features that help to classify the living groups of placental mammals. Through recent work by the same team at UCL, this issue was resolved by creating a new tree of life for placental mammals, including these early forms, which was described in a study published in Biological Reviews yesterday.

First author of both papers, Dr Thomas Halliday (UCL Earth Sciences and Genetics, Evolution & Environment), said: "The mass extinction that wiped out the dinosaurs 66 million years ago is traditionally acknowledged as the start of the 'Age of Mammals' because several types of mammal appear for the first time immediately afterwards.

"Many recent studies suggest that little changed in mammal evolution during the Paleocene but these analyses don't include fossils from that time. When we look at the mammals that were present, we find a burst of evolution into new forms, followed by specialisation that finally resulted in the groups of mammals we see today. The earliest placental mammal fossils appear only a few hundred thousand years after the mass extinction, suggesting the event played a key role in diversification of the mammal group to which we belong."

The team studied the bones and teeth of 904 placental fossils to measure the anatomical differences between species. This information was used to build an updated tree of life containing 177 species within Eutheria (the group of mammals including all species more closely related to us than to kangaroos) including 94 from the Paleocene - making it the tree with the largest representation from Paleocene mammals to date. The new tree was analysed in time sections from 140 million years ago to present day, revealing the change in the variety of species.

Three different methods were used by the team to investigate the range and variation of the mammals present and all showed an explosion in mammal diversity after the dinosaur extinction. This is consistent with theories that mammals flourished when dinosaurs were no longer hunting them or competing with them for resources.

Dr Anjali Goswami (UCL Genetics, Evolution & Environment), added: "Extinctions are obviously terrible for the groups that go extinct, non-avian dinosaurs in this case, but they can create great opportunities for the species that survive, such as placental mammals, and the descendants of dinosaurs: birds."

Professor Paul Upchurch (UCL Earth Sciences), co-author of the Biological Reviews study, added: "Several previous methodological studies have shown that it is important to include as many species in an evolutionary tree as possible: this generally improves the accuracy of the tree. By producing such a large data set, we hope that our evolutionary tree for Paleocene mammals is more robust and reliable than any of the previous ones. Moreover, such large trees are very useful for future studies of large-scale evolutionary patterns, such as how early placental mammals dispersed across the continents via land bridges that no longer exist today."

The team are now investigating rates of evolution in these mammals, as well as looking at body size more specifically. Further work will involve building data from DNA into these analyses, to extend these studies to modern mammals.

Source: University College London [December 21, 2015]

The appearance of infectious diseases in new places and new hosts, such as West Nile virus and Ebola, is a predictable result of climate change, says a noted zoologist affiliated with the Harold W. Manter Laboratory of Parasitology at the University of Nebraska-Lincoln.

In an article published online today in conjunction with a special issue of the Philosophical Transactions of the Royal Society B, Daniel Brooks warns that humans can expect more such illnesses to emerge in the future, as climate change shifts habitats and brings wildlife, crops, livestock, and humans into contact with pathogens to which they are susceptible but to which they have never been exposed before.

"It's not that there's going to be one 'Andromeda Strain' that will wipe everybody out on the planet," Brooks said, referring to the 1971 science fiction film about a deadly pathogen. "There are going to be a lot of localized outbreaks putting pressure on medical and veterinary health systems. It will be the death of a thousand cuts."

Brooks and his co-author, Eric Hoberg, a zoologist with the U.S. National Parasite Collection of the USDA's Agricultural Research Service, have personally observed how climate change has affected very different ecosystems. During his career, Brooks has focused primarily on parasites in the tropics, while Hoberg has worked primarily in Arctic regions.

Each has observed the arrival of species that hadn't previously lived in that area and the departure of others, Brooks said.

"Over the last 30 years, the places we've been working have been heavily impacted by climate change," Brooks said in an interview last week. "Even though I was in the tropics and he was in the Arctic, we could see something was happening." Changes in habitat mean animals are exposed to new parasites and pathogens.

For example, Brooks said, after humans hunted capuchin and spider monkeys out of existence in some regions of Costa Rica, their parasites immediately switched to howler monkeys, where they persist today. Some lungworms in recent years have moved northward and shifted hosts from caribou to muskoxen in the Canadian Arctic.

But for more than 100 years, scientists have assumed parasites don't quickly jump from one species to another because of the way parasites and hosts co-evolve.

Brooks calls it the "parasite paradox." Over time, hosts and pathogens become more tightly adapted to one another. According to previous theories, this should make emerging diseases rare, because they have to wait for the right random mutation to occur.

However, such jumps happen more quickly than anticipated. Even pathogens that are highly adapted to one host are able to shift to new ones under the right circumstances.

Brooks and Hoberg call for a "fundamental conceptual shift" recognizing that pathogens retain ancestral genetic capabilities allowing them to acquire new hosts quickly.

"Even though a parasite might have a very specialized relationship with one particular host in one particular place, there are other hosts that may be as susceptible," Brooks said.

In fact, the new hosts are more susceptible to infection and get sicker from it, Brooks said, because they haven't yet developed resistance.

Though resistance can evolve fairly rapidly, this only changes the emergent pathogen from an acute to a chronic disease problem, Brooks adds.

"West Nile Virus is a good example - no longer an acute problem for humans or wildlife in North America, it nonetheless is hhere to stay," he said.

The answer, Brooks said, is for greater collaboration between the public and veterinary health communities and the "museum" community - the biologists who study and classify life forms and how they evolve.

In addition to treating human cases of an emerging disease and developing a vaccine for it, he said, scientists need to learn which non-human species carry the pathogen.

Knowing the geographic distribution and the behavior of the non-human reservoirs of the pathogen could lead to public health strategies based on reducing risk of infection by minimizing human contact with infected animals, much likethose that reduced the incidence of malaria and yellow fever by reducing human contact with mosquitos.

Museum scientists versed in understanding the evolutionary relationships among species could use this knowledge to anticipate the risk of the pathogen becoming established outside of its native range.

Brooks, who earned his bachelor's and master's degrees from the University of Nebraska-Lincoln, was a zoology professor at the University of Toronto for 30 years until he retired early in 2011 to devote more time to his study of emerging infectious disease. In addition to being a senior research fellow with UNL's Manter Laboratory, he is a visiting senior fellow at the Universidade Federal do Parana, Brazil, funded by the Ciencias sem Fronteiras (Sciences without Borders) of the Brazilian government, and a visiting scholar with Debrecen University in Hungary.

Brooks' and Hoberg's article, "Evolution in action: climate change, biodiversity dynamics and emerging infectious disease," is part of a Philosophical Transactions of the Royal Society B issue on "Climate change and vector-borne diseases of humans," edited by Paul Parham, a specialist in infectious disease epidemiology at Imperial College in London.

"We have to admit we're not winning the war against emerging diseases," Brooks said. "We're not anticipating them. We're not paying attention to their basic biology, where they might come from and the potential for new pathogens to be introduced."

Source: University of Nebraska-Lincoln [February 16, 2015]