Using a technique that can tell if a species has passed by from just a sample of water, scientists are developing new ways to assess ecosystems.
Great crested newt [Credit: Imperial College London]
All animals shed fragments of DNA as they go about their lives – in faeces, mucous, sperm and eggs, shed skin, hair and, eventually, their carcasses.
These traces of genetic material can persist in the environment for some time – a matter of weeks in water and up to a few centuries in soil. With new, more sensitive DNA amplification and sequencing techniques, scientists can collect and analyse these fragments in water and soil samples and identify individual species that have passed by.
One area where environmental DNA, or eDNA, is finding practical use is in environmental assessments, for example to check whether any protected species are present before construction works are carried out. Already, Defra in the UK have approved the use of eDNA sampling to assess the presence of protected great crested newts in ponds.
Now, in a new partnership between Imperial College London and environmental ecology consultancy Thomson Ecology, scientists are hoping to expand the use of eDNA. They want to create protocols to assess whether different areas are home to key protected species, including crayfish, water voles, otters and reptiles.
As well as looking at key protected species for conservation, the team want to use eDNA for biosecurity, by identifying invasive species. For example, as well as native crayfish, some UK waters have been occupied by invasive American Signal Crayfish, which outcompete the native species and damage the local environment. Early detection of invasive crayfish could mean they are dealt with sooner, and cause less damage.
Ultimately, the researchers hope to be able to use eDNA to profile entire ecosystems, analysing water samples to get a snapshot of all the organisms present in the local environment that have shed some DNA.
Victoria Priestley, who is taking on this task for her PhD thesis in the Department of Life Sciences at Imperial, said: "I think eDNA surveys represent a sea change in how we approach survey and monitoring of species.
"There is a lot of effort going into eDNA research globally and once it becomes more established, we should be able to assess what species are present in an area much more quickly. Ultimately we should be able to use it to create a clearer and more detailed picture of global biodiversity."
Efficient Environmental Assessments
Currently, species are assessed based on intensive field surveys, requiring taxonomic expertise and often involving tagging animals and repeat visits to a site. However, Professor Vincent Savolainen, from the Department of Life Sciences at Imperial, is developing new protocols for various species.
This is paving the way for much simpler and more cost-effective surveying for environmental assessments. Professor Savolainen said: "This research will contribute to developing new indices to meet goals of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the body that assesses the state of biodiversity and of the ecosystem services it provides to society, in response to requests from decision makers."
Although sequencing techniques have improved dramatically in the last few decades, challenges remain in analysing eDNA. The fragments degrade over time, a process enhanced by temperature, microbes, enzymes and salinity.
The rate that eDNA is 'shed' from species to species and individual to individual also requires more research, as does the role of predators in moving eDNA between sites, and especially how eDNA is distributed in aquatic environments.
However, Priestley is positive that eDNA surveys have a bright future: "There is still some way to go before whole-ecosystem eDNA monitoring is standard practice, but I believe that at least in the near future, eDNA will increasingly be one of the options in the survey toolkit, working alongside traditional methods to obtain the best ecological survey data in the most efficient way."
Positive Partnership
Professor Tom Welton, Dean of the Faculty of Natural Sciences, said partnerships like this one help translate research into real-world applications: "This exciting collaboration demonstrates that research across the whole breadth of natural sciences at Imperial, even on newts, has practical applications to real world problems.
"Our partnership with Thomson Ecology will allow our research to have a positive impact on environmental protection and conservation."
Author: Hayley Dunning | Source: Imperial College London [November 25, 2016]
A multidisciplinary research team including University of Granada (UGR) researchers has analyzed two sea bed loggings retrieved from the Alboran Sea's basin at very high resolution and reconstructed climate and oceanographic conditions over the last millennium, including the anthropogenic influence in the westernmost region of the Mediterranean Sea.
Two sea bed loggings from the Alboran Sea have been analyzed at very high resolution and have allowed to reconstruct climate and oceanographic conditions as well as anthropogenic influence in the westernmost region of the Mediterranean Sea over that period [Credit: UGRdivulga]
Global warming, climate change and their effects on health and safety are probably the worst threats in mankind's history. Recent reports from the Intergovernmental Panel on Climate Change (IPCC 2007, 2014) have accumulated scientific evidence that the observed rise in mean ground temperature all over the world from the beginning of the 20th century is probably due to anthropogenic influence.
Moreover, global mean concentration of carbon dioxide in the atmosphere has risen since the industrial revolution due to human activities. This concentration has surpassed that found in ice cores over the last 800 000 years. In January 2016, NASA and the U.S. National Oceanic and Atmospheric Administration (NOAA) revealed that global mean temperature in 2015 was the highest since 1880, when records began.
Reconstructions of the global ground temperature in the Northern Hemisphere over the last millennium show hotter conditions during the so called Medieval Climatic Anomaly (800-1300 A.C.) and cooler temperatures during the Little Ice Age (1300-1850 A.C.).
Natural climate variability
Climate models give us a coherent explanation of the progressive cooling over the last millennium due to a natural climate variability (solar cycle changes and volcanic eruptions). However, we can see that this global tendency has reverted during the 20th century. Climate models are not capable of simulating the fast warming observed during the last century without including human impact along with natural mechanisms of climate forcing.
With this in mind, a multidisciplinary team of researchers has conducted a study reconstructing climate and oceanographic conditions in the westernmost region of the Mediterranean Sea. For that purpose, they have used marine sediments retrieved from the Alboran Sea's basin.
As a semi-closed basin located in a latitude affected by several climate types, it's especially sensitive and vulnerable to anthropogenic and climate forcing. Several organic and inorganic geochemical indicators have been integrated in the model for this research, thus deducing climate variables such as sea surface temperature, humidity, changes in vegetation cover, changes in sea currents, and human impact.
These indicators have shown consistent climate signals in the two sea bed loggings—essentially hot and dry climate conditions during the Medieval Climatic Anomaly, which switched to mostly cold and wet conditions during the Little Ice Age. The industrial period showed wetter conditions than during the Little Ice Age, and the second half of the 20th century has been characterized by an increasing aridity.
Climate variability in the Mediterranean region seems to be driven by variations in solar irradiation and changes in the North Atlantic Oscillation (NAO) during the last millennium. The NAO alternates a positive phase with a negative one. The positive phase is characterized by western winds, which are more intense and move storms towards northern Europe, which resulted in dry winters in the Mediterranean region and the north of Africa during the Medieval Climatic Anomaly and the second half of the 20th century.
In contrast, the negative phase is associated with opposite conditions during the Little Ice Age and the industrial period. Our records show that during NAO prolonged negative phases (1450 and 1950 A.C.), there occurred a weakening of the thermohaline circulation and a reduction of "upwelling" events (emergence of colder, more nutrient-rich waters). Anthropogenic influence shows up in the unprecedented increase of temperature, progressive aridification and soil erosion, and an increase of polluting elements since the industrial period. On a broad scale, atmospheric circulation patterns, oceanic circulation patterns (the NAO and the Atlantic meridional overturning circulation), and variations in solar irradiance seem to have played a key role during the last millennium.
Results show that recent climate records in the westernmost region of the Mediterranean Sea are caused by natural forcing and anthropogenic influence. The main conclusions derived from this research have been published in a special volume of the >Journal of the Geological Society of London about climate change during the Holocene.
The London architectural studio «Two Create» has created a colorful interior for a new modern hospital of Queen Elizabeth in Birmingham. The hospital interior looks rather cheerful and gives only positive emotions. Green apartments give more healthy happy life.
Industrialized nations that view wildfire as the enemy have much to learn from people in some parts of the world who have learned to live compatibly with wildfire, says a team of fire research scientists.
A locale in the French Western Pyrenees, where communities practice fire management to maintain seasonally flammable grassland, shrub and woodland patches for forage and grazing animals [Credit: Michael Coughlan]
The interdisciplinary team say there is much to be learned from these "fire-adaptive communities" and they are calling on policy makers to tap that knowledge, particularly in the wake of global warming.
Such a move is critical as climate change makes some landscapes where fire isn't the norm even more prone to fire, say the scientists in a new report published in a special issue of the >Philosophical Transactions of the Royal Society B.
"We tend to treat modern fire problems as unique, and new to our planet," said fire anthropologist Christopher Roos, Southern Methodist University, Dallas, lead author of the report. "As a result, we have missed the opportunity to recognize the successful properties of communities that have a high capacity to adapt to living in flammable landscapes—in some cases for centuries or millennia."
One such society is the ethnically Basque communities in the French Western Pyrenees, who practice fire management to maintain seasonally flammable grassland, shrub and woodland patches for forage and grazing animals. But the practice is slowly being lost as young people leave farming.
Additionally, Aboriginal people in the grasslands of Western Australia use fire as part of their traditional hunting practices. Children begin burning at a very young age, and the everyday practice is passed down. These fires improve hunting successes but also reduce the impact of drought on the size and ecological severity of lightning fires.
Social institutions support individual benefits, preserve common good
Fire-adaptive communities have social institutions in place that support individual benefits from fire-maintained landscapes while preserving the common good, said Roos, whose fire research includes long-term archaeological and ecological partnerships with the Pueblo of Jemez in New Mexico.
"These institutions have been shaped by long-histories with wildfire, appropriate fire-use, and the development of social mechanisms to adjudicate conflicts of interest," said Roos, an associate professor in the SMU Department of Anthropology. "There is a wealth of tried and tested information that should be considered in designing local fire management."
The authors note that globally, a large number of people use fire as a tool to sustain livelihoods in ways that have been handed down across many generations. These include indigenous Australians and North Americans, South Asian forest dwellers, European farmers, and also hunters, farmers and herders in tropical savannahs.
Global Warming will likely bring new fire problems, more flammable landscapes
Global Warming will likely bring new fire problems, such as making some landscapes more flammable, Roos said. More effort will be required to balance conflicting fire management practices between adjacent cultures. Currently most fire-related research tends to be undertaken by physical or biological scientists from Europe, the United States and Australia. Often the research treats fire challenges as exclusively contemporary phenomena for which history is either absent or irrelevant.
"We need national policy that recognizes these dynamic challenges and that will support local solutions and traditional fire knowledge, while providing ways to disseminate scientific information about fire," Roos said.
The authors point out that one of the greatest policy challenges of fire on a warming planet are the international consequences of smoke plumes and potential positive feedbacks on climate through carbon emissions. Most infamously, wildfire smoke plumes have had extraordinary health impacts during Southeast Asian "haze" events, which result in increased hospitalization and mortality in the region.
Not all fire is a disaster; we must learn to live with and manage fire
Carbon emissions from wildfires can be as much as 40 percent of fossil fuel emissions in any given year over the last decade. Although only deforestation fires and land conversion are a net carbon source to the atmosphere, the contribution of wildfires to global carbon emissions is non-trivial and should be a formal component of international climate dialogs.
"It is important to emphasize that not all fire is a disaster and we must learn how to both live with as well as manage fire," said co-author Andrew Scott, earth sciences professor at Royal Holloway University of London.
The report, "Living on a flammable planet: interdisciplinary, cross-scalar and varied cultural lessons, prospects and challenges," was published May 23, 2016 by The Royal Society, the U.K.'s independent scientific academy.
Authors call for holistic study of fire on Earth
The authors are from the United States, Great Britain, Canada, Australia, South Africa and Spain. The synthesis emerged from four days of international meetings sponsored by the Royal Society - the first of its kind for fire sciences.
The authors advocate for greater collaboration among researchers studying all aspects of fire.
Pyrogeography—the holistic study of fire on Earth, "may be one way to provide unity to the varied fire research programs across the globe," the authors write.
"Fire researchers across disciplines from engineering, the natural sciences, social sciences and the humanities need to develop a common language to create a holistic wildfire science," said Roos. "The magnitude of the wildfire challenges we face on a warming planet will demand greater collaboration and integration across disciplines, but our job won't be done unless we are also able to translate our research for policymakers, land managers, and the general public."
Source: Southern Methodist University [June 01, 2016]
A cross-party group of MPs has launched a fresh bid to return the so-called Elgin Marbles to Greece on the 200th anniversary of the British Government’s decision to buy them — a move that campaigners said could help the UK secure a better deal during the Brexit talks with the EU.
The issue has long been a source of tension between, on one side, the UK Government and British Museum, where the 2,500-year-old marbles are currently on display, and, on the other, Greece and international supporters of the reunification of the Parthenon temple's sculptures.
About half the surviving sculptures were taken from the Parthenon in Athens by Thomas Bruce, the seventh Earl of Elgin, and later bought by the British Government after parliament passed an Act that came into force on 11 July, 1816. The other half are currently in the Acropolis Museum in Greece.
The circumstances in which Lord Elgin removed about the sculptures are disputed, with some claiming he effectively stole them while Greece was ruled by the Ottoman Empire.
>The Parthenon Sculptures (Return to Greece) Bill will be presented on the anniversary by Liberal Democrat MP Mark Williams, supported by Conservative Jeremy Lefroy and 10 other MPs from Labour, the SNP and Plaid Cymru.
Mr Williams said: “These magnificent artefacts were improperly dragged and sawn off the remains of the Parthenon.
“This Bill proposes that the Parliament should annul what it did 200 years ago. In 1816 Parliament effectively state-sanctioned the improper acquisition of these impressive and important sculptures from Greece.
“It’s time we engaged in a gracious act. To put right right a 200-year wrong.”
The sculptures are some of the finest ever created and the Parthenon is arguably Europe’s greatest monument. The French Romantic poet Alphonse de Lamartine once described it as “the most perfect poem ever written in stone on the surface of the earth”.
Greece has sought the return of the sculptures ever since victory in the War of Independence in 1832. During the war, Greek fighters even gave bullets to Ottoman soldiers besieged on the Acropolis because they were damaging the Parthenon by removing lead fittings to make ammunition after running out.
Andrew George, chair of the British Association for the Reunification of the Parthenon Sculptures, said the Parthenon sculptures were “some of the most remarkable antiquities on the globe” and people should be able to see them in one place.
They were also, he said, a national symbol of Greece.
“The issue has generated strong feelings in Greece and rightly so,” Mr George said. “We have to take seriously something which is clearly of great significance to the people of Greece.”
Polls have consistently shown that a majority of the British people support reunification. A poll for the The Times newspaper found the general public backed sending the marbles back to Greece by two to one. And an Ipsos-Mori poll found 69 per cent of those familiar with the issue were in favour of returning the sculptures, compared to just 13 per cent against.
Mr George said the case for returning the sculptures was stronger following the Brexit vote.
“If we are about the negotiate a decent trade deal with our European friends, the last thing we want to do is to show the kind of raspberries and two-fingers that [Nigel] Farage was displaying in the European Parliament the other day,” he said.
It would be in the British interest to demonstrate that leaving the EU “doesn’t involve us becoming inward-looking and xenophobic towards the EU, but more confident, more able to be gracious”.
“And there could be no better demonstration of that generosity and graciousness than to do what would be the right thing by the Greeks,” Mr George said.
Professor Athanasios Nakasis, president of the Hellenic branch of the International Council On Monuments and Sites, said allowing reunification would mean a lot for his country, but would also be welcomed around the world.
“Emotionally, the return of the marbles to the place where the rest of the monument resides would be a source of pride for Greeks, since the Athenian Acropolis is an important symbolic centre of the modern nation,” he said.
“From the perspective of the International Council on Monuments and Sites, the reunification of the scattered fragments of the Parthenon would be a positive development, since one of the fundamental principles of our organisation is that the integrity of monuments ought to be preserved, both internally and with respect to their historical contexts.”
The British Museum argues that it "tells the story of cultural achievement throughout the world, from the dawn of human history over two million years ago until the present day".
"The Parthenon Sculptures are a vital element in this interconnected world collection. They are a part of the world’s shared heritage and transcend political boundaries," it says.
"The Acropolis Museum allows the Parthenon sculptures that are in Athens (approximately half of what survive from antiquity) to be appreciated against the backdrop of ancient Greek and Athenian history. The Parthenon sculptures in London are an important representation of ancient Athenian civilisation in the context of world history."
Under David Cameron, the UK Government has remained opposed to allowing the reunification of the Parthenon sculptures, which would require an Act of Parliament to change the laws governing the British Museum.
In 2011, he joked, predictably, that Britain was not going to "lose its marbles".
________________________
PARTHENON SCULPTURES (RETURN TO GREECE) BILL
CONTENTS 1 Return of the Parthenon Sculptures 2 Amendment of the British Museum Act 1963 3 Other artefacts 4 Short title and commencement
A BILL TO Make provision for the transfer of ownership and return to Greece of the artefacts known as the Parthenon Sculptures, or Elgin Marbles, purchased by Parliament in 1816; to amend the British Museum Act 1963 accordingly; and for connected purposes.
BE IT ENACTED by the Queen’s most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:
1 Return of the Parthenon Sculptures
(1)Ownership of the collection of artefacts known as the ‘Parthenon Sculptures’, or the ‘Elgin Marbles’, is transferred to the government of the Hellenic Republic, subject only to subsections (2) and (4). (2)The artefacts comprising the collection in subsection (1) shall be determined by the Secretary of State by regulation. (3)Before making a determination under subsection (2), the Secretary of State must consult— (a)the Trustees of the British Museum, (b)representatives of the Government of the Hellenic Republic, and (c)any other person, body or institution that the Secretary of State believes to be appropriate. (4)Subsection (1) has effect on the coming into force of an agreement between the Government of the United Kingdom and the Government of the Hellenic Republicin which terms are agreed relating to— (a)arrangements for the suitable transportation of the collection determined under subsection (2); (b)responsibility for the costs of such transportation; (c)arrangements and conditions for the maintenance and display of the collection; and (d)access to the collection for: (i)experts (ii)students, and (ii)members of the public. (5)The power to— (a) make regulations under subsection (2), or (b) enter into an agreement under subsection (4) is exercisable by statutory instrument which may only be made after a draft of the instrument has been laid before, and approved by a resolution of, each House of Parliament.
2 Amendment of the British Museum Act 1963
(1)In section 5 of the British Museum Act 1963 (disposal of objects), after subsection (4) insert— “(5)Nothing in this section may be interpreted as applying to an artefact that— (a)has been determined to be part of the collection under section 1(1) of the Parthenon Sculptures (Return to Greece) Act 2016, or (b)is under active consideration by the Secretary of State for determination as to whether or not the artefact is part of that collection.” (2)In section 9 of the British Museum Act 1963 (transfers to other institutions) after subsection (1) insert— “(2)Nothing in this section may be interpreted as applying to an artefact that— (a)has been determined to be part of the collection under section 1(1) of the Parthenon Sculptures (Return to Greece) Act 2016, or (b)is under active consideration by the Secretary of State for determination as to whether or not the artefact is part of that collection.”
3 Other artefacts
Nothing in this Act shall be interpreted as applying to any artefact forming part of a collection within a national museum or gallery other than the artefacts mention in section 1.
4 Short title and commencement
(1)This Act may be cited as the Parthenon Sculptures (Return to Greece) Act 2016. (2)This Act comes into force on the day after the day on which it receives Royal Assent.
________________________
Author: Ian Johnston | Source: Independent [July 11, 2016]
We needed an identity that could reflect what's special about our product, capture ITV's humanness and warmth and make the brand feel alive. We needed a logo that could wrap itself around a broad range of content rather than feel like a corporate badge.
Our creative platform was born from the fact that at ITV, we don't just make TV programmes, we capture life in all its glory and put it centre stage for everyone to enjoy. The new identity needed to bridge all these areas.
ITV is home to the biggest and best loved shows and talent in British popular culture; we reflect and enhance British life and at times define it. We've never told anyone who we are or why we matter. As a result, their affection was with our shows, not the brand. We were a faceless corporation without a heart.
Our brief was to create an identity that could build an emotional connection with the nation and turn them from pure viewers into fans of ITV, not just our programming.
We required a unique and approachable identity to reflect ITV's position as a human and friendly broadcaster 'at the heart of popular culture'. We based the marque on handwriting, its curves signalling an intimacy with audiences without jeopardizing the organisation's status as large and corporate.
The logotype was divided into five segments: each of which 'picks' a different colour from its background. The ability to pick colours from the background allowed the logo to compliment its surroundings. This creates a unique innovation where no two logos are ever alike.
By Week 5 of the rebrand, 52% like or love the new logo. Prompted Awareness of the new logo is now on par with the weekly reach of ITV. Reactions are really positive; it is seen as modern and eye catching. Just over half of those who were aware of a change to ITV, either loved or liked it. When compared with other broadcasters' logos, ITV's was seen as modern, colourful, bright and attractive while BBC, Channel 4 and FIVE were stronger for being boring, old fashioned and dull.
Type of entry: Graphic Design & Design Crafts;
Category: Large Scale Logo and Visual Design;
Advertiser: ITV;
Product/Service: ITV NETWORK;
Agency: ITV CREATIVE London, UNITED KINGDOM;
Executive Creative Director: Phil Lind (ITV Creative);
Head Of Design: Neill Pitt (ITV Creative);
Head Of Design: Mark Gouldie (ITV Creative);
Designer: Jason Ford (ITV Creative);
Designer: Joe Lewis (ITV Creative);
Brand Designer: Matt Rudd (Rudd Studio).
At the Heart of Popular Culture, 7 out of 10 [based on 218 votes]
A new study presents evidence that the rise of atmospheric oxygenation did indeed occur 2.4-2.1 billion years ago. It also shows that biological usage of copper became prominent after the so called 'Great Oxidation Event.' An international team of researchers has recently published the study in the Proceedings of the National Academy of Sciences.
According to a new study the rise of atmospheric oxygenation occurred 2.4-2.1 billion years ago and that biological usage of copper became prominent after the so called 'Great Oxidation Event' [Credit: Catarina Nilsson/Mostphotos]
"Our findings make it possible to reconstruct nutrient content in early marine settings and demonstrate that the iron-rich content of the early oceans must have severely restricted the availability of nutrients important for life", says Dr Ernest Chi Fru of Stockholm University, who has led the research group.
The study suggests a gradual shift in mainly negative copper isotopic composition of marine carbon-rich sediments, beginning at 2.4 billion years ago (Ga), to permanently positive values after 2.3 Ga. The authors argue that the change reflects the drawn-out nature of the Great Oxidation Event (GOE), when atmospheric oxygen content went from virtually nothing, starting at 2.4 Ga, to peak at near present day levels by 2.3 Ga.
Fundamentally, the high iron content of the early oceans are suggested to have played a critical role in determining trace metal availability, whereby copper levels increased when decreasing marine iron content fell by about 1 000 times after the GOE. The research has been made by examining carbon-rich rocks deposited at the bottom of ancient oceans 2.66-2.1 billion years ago.
"The appearance of oxygen in the atmosphere is one of the most important changes in Earth's geological history that enabled the evolution of oxygen based life. Understanding the chemistry of the very early oceans and how nutrients were made available, guide our steps towards understanding the processes that govern our own evolution", says Dr Ernest Chi Fru of Stockholm University.
The study provides a tool for tracking how oxygen levels have fluctuated through Earth's history and the evolutionary changes that accompanied these fluctuations.
"Our study is highlighting how the isotopic ratios of copper can unlock the evolution of Earth's early oceans from being oxygen-poor to more like they are today. We now hope to apply this technique to understanding other major geological events in the Earth's history", says Professor Dominik Weiss, co-author from Imperial College London.
Fluctuating sea levels and global cooling caused a significant decline in the number of crocodylian species over millions of years, according to new research.
Image of Sarcosuchus [Credit: Imperial College London and Robert Nicholls]
Crocodylians include present-day species of crocodiles, alligators, caimans and gavials and their extinct ancestors. Crocodylians first appeared in the Late Cretaceous period, approximately 85 million years ago, and the 250 million year fossil record of their extinct relatives reveals a diverse evolutionary history.
Extinct crocodylians and their relatives came in all shapes and sizes, including giant land-based creatures such as Sarcosuchus, which reached around 12 metres in length and weighed up to eight metric tonnes. Crocodylians also roamed the ocean -- for example, thalattosuchians were equipped with flippers and shark-like tails to make them more agile in the sea.
Many crocodylians survived the mass extinction that wiped out almost all of the dinosaurs 66 million years ago, but only 23 species survive today, six of which are classified by the International Union for Conservation of Nature as critically endangered and a further four classified as either endangered or vulnerable.
In a new study published in Nature Communications, researchers from Imperial College London, the University of Oxford, the Smithsonian Institution and the University of Birmingham compiled a dataset of the entire known fossil record of crocodylians and their extinct relatives and analysed data about Earth's ancient climate. They wanted to explore how the group responded to past shifts in climate, to better understand how the reptiles may cope in the future.
Crocodylians are ectotherms, meaning they rely on external heat sources from the environment such as the Sun. The researchers conclude that at higher latitudes in areas we now know as Europe and America, declining temperatures had a major impact on crocodylians and their relatives.
At lower latitudes the decline of crocodylians was caused by areas on many continents becoming increasingly arid. For example, in Africa around ten million years ago, the Sahara desert was forming, replacing the vast lush wetlands in which crocodylians thrived. In South America, the rise of the Andes Mountains led to the loss of a proto-Amazonian mega wetland habitat that crocodylians lived in around five million years ago.
Marine species of crocodylians were once widespread across the oceans. The team found that fluctuations in sea levels exerted the main control over the diversity of these creatures. For example, at times when the sea level was higher it created greater diversity because it increased the size of the continental shelf, providing the right conditions near the coast for them and their prey to thrive.
Interestingly, the Cretaceous-Paleogene mass extinction event, which wiped out many other creatures on Earth nearly 66 million years ago including nearly all of the dinosaurs, had positive outcomes for the crocodylians and their extinct relatives. The team found that while several groups did go extinct, the surviving groups rapidly radiated out of their usual habitats to take advantage of territories that were now uninhabited.
In the future, the team suggest that a warming world caused by global climate change may favour crocodylian diversification again, but human activity will continue to have a major impact on their habitats.
Dr Philip Mannion, joint lead author from the Department of Earth Science and Engineering at Imperial College London, said: "Crocodylians are known by some as living fossils because they've been around since the time of the dinosaurs. Millions of years ago these creatures and their now extinct relatives thrived in a range of environments that ranged from the tropics, to northern latitudes and even deep in the ocean. However, all this changed because of changes in the climate, and crocodylians retreated to the warmer parts of the world. While they have a fearsome reputation, these creatures are vulnerable and looking back in time we've been able to determine what environmental factors had the greatest impact on them. This may help us to determine how they will cope with future changes."
The next step for the researchers will be for them to look at similar patterns in other fossil groups with long histories, such as mammals and birds to determine how past climate influenced them.
Source: Imperial College London [September 24, 2015]
Global populations of vertebrates -- mammals, birds, reptiles, amphibians, and fish -- have declined by 58 percent between 1970 and 2012, states a new report from World Wildlife Fund (WWF). Animals living in the world's lakes, rivers, and freshwater systems have experienced the most dramatic population declines, at 81 percent. Because of human activity, the report states that without immediate intervention global wildlife populations could drop two-thirds by 2020.
"This research delivers a wake-up call that for decades we've treated our planet as if it's disposable," said Carter Roberts, WWF president and CEO. "We created this problem. The good news is that we can fix it. It requires updating our approach to food, energy, transportation, and how we live our lives. We share the same planet. We rely on it for our survival. So we are all responsible for its protection."
The top threat to wildlife is habitat loss and degradation, driven primarily by increasing demand for food and energy. According to the report, global food production is the leading cause for destruction of habitats and overexploitation of wildlife. Agriculture currently occupies approximately one-third of Earth's total land area and accounts for 70 percent of all freshwater use.
Wild animals are not the only ones at risk; the report states that increased pressure threatens the natural resources that all life -- including humanity -- depend on.
The report demonstrates the need to rethink how we produce, consume, measure success and value the natural environment, and calls for an urgent system change by individuals, businesses and governments. The report also illustrates the positive momentum that is building by highlighting recent global agreements on climate change and sustainable development. In particular, the report recognizes the 2030 Agenda for Sustainable Development as an essential guide to decision-making that can ensure that the environment is valued alongside economic and social interests.
"A strong natural environment is the key to defeating poverty, improving health and developing a just and prosperous future," said Marco Lambertini, WWF director general. "We have proven that we know what it takes to build a resilient planet for future generations, we just need to act on that knowledge."
>Living Planet Report 2016: Risk and resilience in a new era is the eleventh edition of WWF's biennial flagship publication. The report tracks over 14,000 vertebrate populations of over 3,700 species from 1970 to 2012 and includes research from the Global Footprint Network and the Zoological Society of London.
In the summer of 430 B.C., a mass outbreak of disease hit the city of Athens, ravaging the city’s population over the next five years. In his History of the Peloponnesian War, the historian Thucydides, who witnessed the epidemic, described victims’ “violent heats in the head,” “redness and inflammation in the eyes,” and tongues and throats “becoming bloody and emitting an unnatural and fetid breath.” Patients would experience hot flashes so extreme, he wrote, that they “could not bear to have on [them] clothing or linen even of the very lightest description.” In the later stages of infection, the disease would end with “violent ulceration” and diarrhea that left most too weak to survive.
The Plague at Ashdod by Nicolas Poussin [Credit: WikiCommons]
More than 2,000 years later, the Plague of Athens remains a scientific mystery. Thucydides’ account—the only surviving description of the epidemic—has been the basis for dozens of modern-day theories about its cause, including bubonic plague, cholera, typhoid fever, influenza, and measles. And in June, an article in the journal Clinical Infectious Disease suggested another answer: Ebola.
The article, written by the infectious-disease specialist Powel Kazanjian, is the latest in a string of papers arguing that Athens was once the site of an Ebola outbreak. The surgeon Gayle Scarrow first raised the suggestion in The Ancient History Bulletin in 1988. Eight years later, the epidemiologist Patrick Olson published a letter in Emerging Infectious Diseases, a journal of the Centers for Disease Control and Prevention, comparing the symptoms of the Athens plague to those of Ebola, which had broken out in the Democratic Republic of Congo (then Zaire) and Sudan in 1976. “The profile of the ancient disease,” he concluded, “is remarkably similar.”
But not everyone was on board with Olson’s theory. In a 1996 interview with the The New York Times, the epidemiologist David Morens argued that Thucydides wasn’t the most reliable source: Unlike his contemporary, Hippocrates, he wasn’t a physician, and many of the terms he used to describe the disease’s symptoms were ambiguous. For example, the ancient Greek phlyktainai could refer to either blisters or callouses. Noting Thucydides’ claim that the epidemic had originated “in the parts of Ethiopia above Egypt” (today’s sub-Saharan Africa), Morens also questioned how people with Ebola, a highly contagious and deadly disease, could make it all the way to Greece without dying along the way.
The duration of the Athens epidemic also presented another problem: At five years, it was much longer than any known Ebola outbreaks, the majority of which lasted less than a year. And finally, Morens asked, if Ebola had made it out of Africa millennia ago, why were there no other accounts of the disease re-appearing anywhere on Earth until 1976?
Unfortunately for both Olson and Morens, however, neither had a more concrete way to back up their arguments. Their efforts to identify the Plague of Athens, like all the other efforts before them, could only rely on the written record left by Thucydides, which made confirmation more or less impossible.
This, in a nutshell, is the challenge of ancient pathology: With DNA testing, it’s often possible to identify the cause of an epidemic that took place centuries or even millennia ago. Finding remains of those victims to test, though, is another story.
Sometimes, scientists get lucky. In 2001, for example, a mass grave was uncovered at a construction site in Vilnus, Lithuania. Based on uniform fragments found in the grave, the bodies were identified as belonging to soldiers in Napoleon’s army—somewhere between 2,000 and 3,000 of them, hurriedly buried during the retreat from Moscow. When a team of anthropologists examined dental pulp taken from the bodies, they found that around one-third of them had died of typhus, a finding confirmed by tests of dead lice found at the site (the disease is transmitted through lice). Researchers had long suspected that typhus had contributed to Napoleon’s eventual defeat, but because knowledge of the disease was scant during his lifetime, historical accounts alone had never been enough to confirm it.
For the Plague of Athens, it seemed like a similar turning point had arrived in 1994, when during excavations for a planned Athens metro station at Kerameikos, an ancient graveyard used from the early Bronze age through Roman times. The excavators uncovered thousands of previously undiscovered tombs—including a set of seemingly hurried, unceremonious mass burials dating to 430 B.C., the year of the Plague of Athens.
Control of the site was turned over from the construction company to the Greek Ministry of Culture, which handles the discoveries of ancient ruins. In 2000, archaeologists turned over three teeth found at the site to a University of Athens team led by Manolis Papagrigorakis, an orthodontist and professor of dentistry, for DNA testing. Examining the dental pulp found in the teeth, Papagrigorakis’ team ran tests for seven diseases that had previously been suggested by other scholars: plague, typhus, anthrax, tuberculosis, cowpox, cat-scratch disease, and typhoid fever. The only match they identified on all three teeth was with the pathogen for typhoid fever. The researchers published the findings from their analysis in the International Journal of Infectious Diseases in 2006.
Far from solving the mystery, though, Papagrigorakis’s team only muddled it further. In a letter to the editor in the same journal, zoologists from Oxford University and the University of Copenhagen argued that Papagrigorakis’s methodology was flawed because he failed to do a phylogenetic analysis (a way of examining evolutionary relationships) on the teeth. Using the DNA data published in Papagrigorakis’s study, they conducted their own phylogenetic analysis, concluding that the DNA of the tooth bacteria was related to, but not the same as, that of the pathogen for typhoid fever. “The Athens [DNA] sequence and typhoid would have shared a common ancestor in the order of millions of years ago,” they wrote.
The authors also suggested another possibility: that the DNA found in the teeth wasn’t from the Plague of Athens pathogen at all. “While we cannot exclude the possibility that the Athens sequence is a previously unidentified infectious agent,” they concluded, “it is quite reasonable to assume that the sequence is actually that of a modern, free-living soil bacterium, a possibility that could have been explored by extracting DNA from surrounding soil samples as additional negative controls.”
Papagrigorakis currently has a new study underway, using more modern techniques and a greater number of tooth samples, that he hopes will help to settle the debate. In the decade since he published his Athens study, advancements in DNA-sequencing technology have enabled scientists to answer a number of lingering questions about ancient epidemics, making new discoveries from very old tooth samples. In 2011, for example, scientists used teeth taken from bodies in one of London’s so-called “plague pits” to sequence the genome of the bacterium y. pestis, the source of the Black Death epidemic that had swept Europe in the 14th century. By comparing the old genome to modern-day strains, the researchers were able to reconstruct the bacterium’s evolutionary path over the centuries, finding support for the idea that the 14th-century pathogen was likely the root of the evolutionary tree leading to more recent outbreaks.
And in a 2014 study published in the Lancet Infectious Diseases, scientists were able to prove for the first time that the Plague of Justinian—which killed about 50 million people in Europe and the Byzantine Empire between 600 and 800 A.D.—was actually a strain of y. pestis, making it the first known outbreak. The team made its discovery by sequencing DNA from teeth taken from human remains that had been found in a German graveyard and dated to the time of the epidemic.
Even when ancient specimens are available, though, they may not be enough to identify a disease. Bacteria, like typhoid and plague, can be identified through DNA sampling, but this isn’t always the case with viruses. Many of them, including the viruses for Ebola, influenza, and measles, require an RNA sample for positive identification—and thus far, the oldest preserved RNA viral genome belongs to a 700-year-old specimen of caribou feces, much more recent than the Athens samples from in the 5th century B.C. The structure of RNA makes it much more unstable—and therefore more prone to degradation—than DNA, meaning that if the Plague of Athens was viral rather than bacterial, its source may remain a mystery.
“If Ebola virus was there, we will never know,” said Vinent Racaniello, a professor of microbiology at Columbia University professor and the host of the podcast This Week in Virology. “For that, we’ll need a time machine to bring us back to get samples.”
Partially due to these limitations, Kazanjian’s recent study doesn’t delve into dental-pulp analysis data. His argument is based on the similarity between the symptoms of the Plague of Athens and those of Ebola, an argument that he believes is strengthened by observations from the latest Ebola outbreak. The paper ends with a chart of the symptoms described by Thucydides, listed side-by-side against the symptoms of eight modern diseases that had previously been floated as possible explanations; of all of them, the symptoms for Ebola have the most overlap.
Even so, Kazanjian cautioned against referring to Ebola as a “probable” or even a “likely” cause. “The most accurate statement is that the cause remains unknown, and there are several possibilities,” he said, including that the Plague of Athens may have been a now-extinct disease with Ebola-like symptoms.
He also acknowledges the difficulty of making rigorous comparisons between Thucydides’s descriptions and modern-day medical knowledge: “I try not to get into the trap of saying what the most likely thing is,” he said.
But for Kazanjian—also a historian—solving the puzzle of the Plague of Athens is less compelling than exploring all the possibilities. The inquiry is “clearly fun to do,” he said, “no matter what your background is.”
Author: Simon Davis | Source: The Atlantic [September 16, 2015]
An application has been lodged with the Culture and Tourism Ministry to conduct a surface survey to investigate the ancient city of Satala, which served as a military headquarters in the Roman Empire in the northern Turkish province of Gümüşhane’s Kelkit district.
A surface survey will be carried out in the ancient city of Satala, which served as a military headquarters in the Roman Empire Gümüşhane [Credit: AA]
According to historical records, the city, which is 28 kilometers from the city center, was established by the 15th Apollo Legion, a legion of the Imperial Roman army. It served as a headquarters in the ancient era and also served as an intersection of military roads passing through Anatolia and Cappadocia.
The city was controlled at various times by the Assyrian, Graeco-Macedonian, Roman and Byzantine civilizations.
A 47-arched aqueduct was built to bring water to the ancient city of Satala but only one arch survives today.
The city is believed to cover a very large area. Candles, rings, arms, pots, metal pieces and coins have all been discovered at the site and are now on display at the Istanbul Archaeology Museum, while a bronze bust of Aphrodite is at London’s British Museum.
Kelkit Mayor Ünal Yılmaz said the ancient city of Satala, which is under protection as an archaeological site, had been examined by university academics.
As a result of the examination, a report was prepared by the Gümüşhane Governor’s Office, Kelkit Municipality and academics. In line with the report, an application was made to the Culture and Tourism Ministry to conduct a surface survey.
Yılmaz said no serious work had been carried out in the historical city.
“No work has been implemented here although there were discussions from time to time. Evaluations were also made but nothing was done in practice. Because it is an archaeological site, people were not able to build structures there. I hope the applications will receive a positive response and that works will be initiated,” Yılmaz said.
“Our academics are very hopeful on the issue. We think this area will add a lot to tourism for our province and district after the pre-excavation work is completed,” Yılmaz said.
