Tag Archives: Kristine l Ming Information

Elephant seals ‘recognise vocal rhythm’

Northern elephant seal calling (c) Ari Friedlaender/NMFS 19108Image copyright
Ari Friedlaender

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Male northern elephant seals can weigh more than two tonnes

Male elephant seals recognise the rhythm of one another’s voices, researchers say.

Scientists in the US “decoded” the calls of male elephant seals, revealing that vocal communication played a crucial part in their social lives.

This showed seals communicating their identity with deep, rhythmic calls.

In their Current Biology paper, the team says this is the first example of non-human mammals “using rhythm” in everyday life.

Singing elephants?

Just as humans can identify a particular song based on its distinctive rhythm, this research revealed that male elephant seals could identify each other from the pulsing pattern of their calls.

Lead author Prof Nicolas Mathevon, from the University of Lyon and St Etienne, described these grumping vocalisations as “distinctive”.

They were “very rhythmic, like a metronome”, he told BBC News.

“In the colony, everyone knows who is who… they recognise the voice of all the other males in the colony.”

And this is important in a congested beach colony – at the site the team studied, more than 4,000 seals are packed on to the beach, so it is important to know your neighbours.

Seal social networking

“If you think about the social life of a male elephant seal, it’s actually quite complicated,” said co-author Caroline Casey, from the University of California Santa Cruz.

“Within his own social network, he’s potentially interacting with 20-30 other individuals.”

In these situations, it can be crucial to distinguish quickly between dominant and subordinate males – to avoid a potentially lethal conflict.

“If he gets it wrong, the costs of that mistake are pretty high. We saw a male die last year from a canine through the skull,” Ms Casey said.

In this context, the rhythmic call of a male elephant seal acts as a distinctive “fingerprint”, helping other males decide whether to flee the vicinity.

Image copyright
Colleen Reichmuth

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Male elephant seals compete for access to females

Beachmasters

The research team spent six years studying the colony of more 4,000 elephant seals in Ano Nuevo National Park, California.

They recorded the vocalisations of dominant males, then played back those calls through loudspeakers to subordinate males.

As expected, less dominant males fled the sound of the high status seals, which are referred to as “beachmasters”.

Crucially though, when the researchers artificially modified the rhythm of a call, subordinate males no longer recognised it and did not respond.

If they did not recognise a voice, “they wait and see”, said Prof Mathevon. “It’s their strategy.”

Image copyright
Colleen Reichmuth

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Male northern elephant seals lose up to 40% of their body weight over the breeding season

While doing nothing might seem lazy, this “very efficient strategy” is also potentially life-saving.

During the breeding season, elephant seals haul out from the ocean and stay in the colony for almost 100 days without any food or water.

So, if males do not recognise the rhythm of a call, they simply do not move, and therefore avoid a waste of vital energy.

Prof Patricia Gray, from the University of North Carolina, Chapel Hill, who was not involved in the research, said it had captured “natural animal behaviour in the wild” and shown how important producing and recognising rhythm was to their survival.

She added that understanding how other species used rhythm could “unlock many answers” about how they perceived other animals and their surroundings and how these qualities related to human perception.

Article source: http://www.bbc.co.uk/news/science-environment-40668649

Farm subsidies ‘must be earned’

Michael GoveImage copyright
AFP

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Mr Gove says leaving the EU will allow Britiain to reform how it cares for the environment

Farm subsidies will have to be earned rather than just handed out in future, the Environment Secretary Michael Gove has said in a speech.

Farmers will only get payouts if they agree to protect the environment and enhance rural life, he will say.

The move is part of what he calls his vision for a “green Brexit”.

Farmers’ leaders want the current £3bn total to be spent on the environment, more infrastructure to develop farm businesses, and promoting British food.

The government has promised to keep overall payments at the same level until 2022.

The Tenant Farmers’ Association – which represents tenant farmers in England and Wales – has called for the same amount of money to remain after that time.

Under the EU’s current Common Agricultural Policy (CAP), farmers are paid based on the amount of land they own.

However, in a speech at WWF’s Living Planet Centre in Woking on Friday, Mr Gove said the current system will be abolished after the UK has left the EU.

He criticised the current system for giving money to some of the UK’s wealthiest landowners, for encouraging wastage, and for not recognising “good environmental practice”.

Mr Gove described Brexit as “a once-in-a-lifetime opportunity to reform how we care for our land, our rivers and our seas, how we recast our ambition for our country’s environment, and the planet”.

Loss of wildlife

Critics say under the CAP wealthy UK landowners are given subsidies of up to £3m a year.

The issue was highlighted last year when BBC News revealed that taxpayers are paying more than £400,000 a year to subsidise a farm where a billionaire Saudi prince breeds racehorses.

The Newmarket farm of Khalid Abdullah al Saud – owner of the legendary horse Frankel – is among the top recipients of farm grants, along with the Queen.

Environmentalists will applaud the promise of change; they blame the CAP for the huge loss of wildlife in the British countryside.

The question for Mr Gove will be what detailed policy takes its place.

Image copyright
Getty Images

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The Environment Secretary says that CAP puts resources in the hands of the already wealthy

Mr Gove said in his speech: “There are very good reasons why we should provide support for agriculture. Seventy per cent of our land is farmed – beautiful landscape has not happened by accident but has been actively managed.

“Agriculture is an industry more susceptible to outside shocks and unpredictable events – whether it’s the weather or disease. So financial assistance and mechanisms which can smooth out the vicissitudes farmers face make sense.”

He also expressed a desire to protect the “human ecology” of Britain’s highlands, where farming without subsidy is impossible.

This won’t please radical environmentalists, who want Mr Gove to save money (and in their view enhance the environment) by letting sheep farming wither, and allowing the uplands to revert to natural forest.

The Country Land and Business Association, known as the CLA, accepts the need for reform and has launched a plan for a land management contract.

Ross Murray, president of the CLA – which represents owners of land, property and businesses in England and Wales – said there is “vital work to be done”, including to support farming practices, to manage soils and preserve land.

When pressed on whether rich landowners should received public money, he told BBC Radio 4′s Today programme he was open to change but practices such as tree planting – which are good for the environment but provide landowners with little benefit – should still be recognised.

Asked if farming subsidies could be reduced in the future, he added: “In the long term perhaps, but in the meantime I think we’re going to have to support farmers who provide public goods which could never be provided by the market.”

Craig Bennett, head of Friends of the Earth, welcomed the speech, but said: “Current EU rules aimed at tackling air pollution and climate change and protecting our birds, bees and nature must not be watered down, and mechanisms must be put in place to enforce them post-Brexit.”

One crucial question will be who has the final say on proposed developments in the UK’s prime wildlife sites. At the moment they are protected by the EU as part of Europe’s common heritage. That protection may disappear after Brexit.

Follow Roger on Twitter.


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Article source: http://www.bbc.co.uk/news/science-environment-40673559

UK rhino eggs ‘could save last northern whites’

Egg collection at LongleatImage copyright
Longleat

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Scientists have extracted eggs from rhinos at Longleat Safari park in Wiltshire

A UK zoo is taking part in a radical plan to save the world’s last three northern white rhinos from extinction.

At Longleat safari park, scientists have collected eggs from southern white rhinos – a closely related sub species – to use for IVF.

The eggs will help researchers to develop the technology to help the remaining northern whites to reproduce.

A back-up plan is to mix eggs from the southern white rhinos with sperm from northern whites to create a hybrid.

It means that if the bid to produce a pure northern white rhino fails, at least some of the critically endangered animal’s genes will live on.

Darren Beasley, head of animal operations at Longleat, added: “Effectively the female rhinos would act as IVF mothers, with embryos partly derived from northern white male sperm.

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Sudan is the only male northern white rhino on the planet

“If the procedure works, the hope would be that southern white females would carry the developing embryos for up to 18 months before giving birth.”

Experimental fertility technology may be the last hope for northern white rhinos.

The animals were once found across central Africa, but illegal poaching, fuelled by the demand for rhino horn, wiped out the wild population.

Today, there are just three of the animals left: a male, who is over 40, and two younger females. The former zoo animals, which are inter-related, are kept under tight security at Ol Pejeta Conservancy in Kenya.

However, a combination of age and fertility problems means that none is able to breed.

Dvůr Králové Zoo in the Czech Republic, which owns the animals, has now enlisted the help of wildlife fertility experts from Germany and Italy.

Image copyright
Longleat

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The team used ultrasound to look inside the rhino’s ovaries

The team believes the northern white’s cousin – the southern white rhino – could be the key to saving the species.

Professor Thomas Hildebrandt, from the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany, said: “We are trying to find a solution for a very critical situation: we have a doomed species.”

They have been collecting eggs from female southern whites living in zoos around Europe.

Longleat Safari Park is the first UK zoo to take part, and on Monday and Tuesday, the team managed to harvest nine eggs from three females.

The rhinos have not mated naturally with the zoo’s male, which is why they were put forward to take part in the study.

Extracting the eggs required millimetre precision.

Prof Hildebrand said: “We have a two-tonne animal, and the ovaries are more than two metres inside.

“We operate on an ovary that is lying next to a blood vessel and if we poke that with our needle, there is a very high risk that the animal dies.

“We have developed a very sophisticated technique to make sure we don’t do any harm to the animals.”

Image copyright
Longleat

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The scientists managed to extract nine eggs from three rhinos

The eggs have now been rushed back to the Avantea clinic in Italy, a lab that specialises in assisted reproduction in animals, where they will be prepared for fertilisation.

A rhino has never been born through IVF before, and the first aim of the project is to refine the technology using southern white rhinos.

So far the team has mixed southern white eggs with southern white sperm, and has achieved cell division in early embryos, which have been cryogenically frozen and stored. None have yet been implanted back into a a rhino.

Later this year, the researchers plan to head to Kenya to harvest eggs from the last two female northern white rhinos. The scientists believe their extraction technique is now so well established it will not put these animals at any risk.

These northern white eggs will be mixed with northern white sperm – and implanted in a surrogate southern white mother – in a bid to produce new offspring.

The fertility scientists admit the chances of success may be slim – but they are optimistic that the technology could help.

Prof Hildebrandt said: “The classical conservationists would not even call this a conservation approach, because it is so technical, so far beyond what you normally do.

“But we hope future generations will understand that this is the way to go. It is a technology that allows us to bring a species back form the brink of extinction that would normally be impossible – and that is our goal.

“We are extremely optimistic that we will achieve that.”

Image copyright
Longleat

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The scientists may create hybrids between southern white and northern white rhinos

But the scientists also have a plan B: mixing the eggs they have collected from southern whites with sperm from northern whites. This would create a hybrid species.

This would not be the first: a cross was born at a zoo in the 1970s after the two sub-species accidentally bred.

But it was little studied. And despite the fact southern and northern white rhinos are very closely related, some questions remain, such as whether a hybrid could breed to produce further offspring.

But with the northern white at such a critical conservation status, it could mean that at least some of its genetic material survives.

Dr Robert Hermes, also from the Leibniz Institute for Zoo and Wildlife Research, said: “Our great hope is to go to Africa to collect eggs from these last two northern white females and the fertilise them so we would have a pure bred northern white rhino embryo.

Image copyright
Longleat

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The technology developed with the Longleat rhinos could also help other species

“But the last northern whites could die any time: anything could happen to them, then all their genetics would be lost. If we have at least 50% of this preserved in a hybrid – we would preserve at least half for future generations.”

This rescue plan – which is also examining the role that stem cell technology could play in the future – is conservation science at its most extreme.

And some wildlife experts believe that rather than pouring money and resources into a species that is nearly doomed, more effort should be put in saving more viable rhinos species, whose numbers have plummeted in recent years as poaching has surged.

But Jan Stejskal, from Dvůr Králové Zoo, says that every effort should be made to save the last northern whites – and this could help other animals too.

He told BBC News: “Rather than conservation, I call this a rescue operation. There is no other option for these animals to reproduce.

“Of course, I have to admit we might not be successful. But on the other hand, we are gathering so much information that could be used for other species.

“I’m convinced this is worth trying, even if we don’t succeed.”

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Article source: http://www.bbc.co.uk/news/science-environment-40655273

Poaching pushes pangolin closer to extinction

African white-bellied pangolinImage copyright
National Botanic Garden of Belgium

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African white-bellied pangolin

Millions of pangolins are being hunted and killed in Africa, raising fears that they are being pushed to extinction.

The pangolin is the world’s most trafficked and poached mammal, because of the demand for its meat and scales.

Conservationists say an international trade ban announced last year must be strictly enforced.

There are concerns that traders are illegally supplying African pangolins to Asian markets.

Populations of Asian pangolins have declined dramatically since the 1960s, leaving the creatures highly endangered.

Daniel Ingram of the University of Sussex worked with researchers in Africa on the first study to assess hunting levels of pangolins in the forests of Central Africa.

“Pangolins have been hunted across Africa for centuries,” Dr Ingram told BBC News. “Because we don’t have population estimates we can’t tell if hunting for food is at sustainable levels or not.

“What we can say is that there is widespread pressure on pangolins from hunting in Central Africa, but we can’t ascertain whether hunting is at sustainable levels or not because we need biology data and population estimates.”

Image copyright
SPL

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Long-tailed pangolin, Congo

The team used data from more than 100 bush markets and hunting sites in 14 African countries to estimate how many pangolins are being killed.

They estimate that 0.4 to 2.7 million pangolins are hunted annually in Central African forests.

Prof Jörn Scharlemann, from the University of Sussex, said overexploitation was one of the main pressures driving wildlife, like the pangolins, closer to extinction, yet data to evaluate the pressures underlying species’ declines was scarce.

“Collating data from local studies collected by hundreds of researchers allows us to provide vital information on the regional exploitation of African pangolins at a critical time for the survival of these species,” he said.

“Bringing these individual studies together allows us to see the bigger picture that can help inform conservation policy and provide the evidence to governments across the world required to take action to use natural resources more sustainably.”

Since 2014, all eight pangolin species in the world have been classified as threatened with extinction on The IUCN Red List of Threatened Species.

The Chinese and Sunda species are now listed as Critically Endangered, the Indian and Philippine pangolins as Endangered, and the four African species as Vulnerable.

It is estimated that since 2000, more than one million pangolins have been traded illegally internationally, which makes them the most trafficked wild mammal in the world.

The research is published in the journal Conservation Letters.

The price of the giant pangolin has risen 5.8 times since the 1990s, despite it being protected.

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Article source: http://www.bbc.co.uk/news/science-environment-40668420

Why dogs are friendly

WolfImage copyright
Monty Sloan

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Some wolves are more sociable than others

Being friendly is in dogs’ nature and could be key to how they came to share our lives, say US scientists.

Dogs evolved from wolves tens of thousands of years ago.

During this time, certain genes that make dogs particularly gregarious have been selected for, according to research.

This may give dogs their distinctive personalities, including a craving for human company.

“Our finding of genetic variation in both dogs and wolves provides a possible insight into animal personality, and may even suggest similar genes may have roles in other domestic species (maybe cats even),” said Dr Bridgett vonHoldt of Princeton University.

The researchers studied the behaviour of domestic dogs, and grey wolves living in captivity. They carried out a number of tests of the animals’ skills at problem-solving and sociability.

Image copyright
Monty Sloan

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Captive wolves gave humans only brief attention

These showed that wolves were as good as dogs at solving problems, such as retrieving pieces of sausage from a plastic lunchbox.

Dogs, however, were much more friendly. They spent more time greeting human strangers and gazing at them, while wolves were somewhat aloof.

DNA tests found a link between certain genetic changes and behaviours such as attentiveness to strangers or picking up on social cues.

Similar changes in humans are associated with a rare genetic syndrome, where people are highly sociable.

Dr Elaine Ostrander of the National Institutes of Health, who was a co-researcher on the study, said the information would be useful in studying human disease.

“This exciting observation highlights the utility of the dog as a genetic system informative for studies of human disease, as it shows how minor variants in critical genes in dogs result in major syndromic effects in humans,” she said.

Image copyright
Daniel Stahler/NPS

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Wolves playing at Yellowstone

Dogs were domesticated from wolves between 20,000 and 40,000 years ago.

New story for domestication of dogs

This process began when wolves that were tolerant of humans sneaked into hunter gatherer camps to feed on food scraps.

Over the course of history, wolves were eventually tamed and became the dogs we know today, which come in all shapes and sizes.

The finding of genetic changes linked to sociability in dogs shows how their friendly behaviour might have evolved.

“This could easily play into the story then of how these wolves leave descendants that are also ‘friendlier’ than others, setting the path for domestication,” said Dr vonHoldt.

The research is published in the journal, Science Advances.

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Article source: http://www.bbc.co.uk/news/science-environment-40655634

LISA Pathfinder: Time called on Europe’s gravity probe

LPF artist's impressionImage copyright
ESA

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Artwork: The LISA Pathfinder demonstration took place more than a million km from Earth

The European Space Agency (Esa) has turned off one of its most successful ever missions.

LISA Pathfinder was sent into orbit in 2015 to prove key technologies that could be used on some future project to detect gravitational waves – the ripples that disturb space-time whenever black holes collide.

The satellite spectacularly surpassed the objectives set for it.

And that success led directly to the selection in June of the LISA mission.

This billion-euro venture, which is envisaged as a trio of satellites, is expected to launch between 2030 and 2034.

It will incorporate many of Pathfinder’s systems, including its all-important laser interferometer instrumentation that we now know has the means necessary to catch gravitational waves (GW) in space.

“LISA Pathfinder has shown that LISA is feasible at full sensitivity, more than we could hope for,” said principal investigator Stefano Vitale.

“I think it has been a stepping stone for GW astronomy, and an incredibly rewarding experience for all the team involved. Thank you, and stay tuned on LISA!” he told BBC News.

  • Europe selects grand gravity mission
  • Third detection of deep space warping
  • Gravity probe exceeds performance goals
  • Europe picks Plato planet-hunter

Image copyright
ESA

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Prof Vitale sends the final commands to LISA Pathfinder

Prof Vitale was invited to send the final “kill commands” to Pathfinder, which has been conducting its measurement demonstration 1.5 million km from Earth in the sunward direction.

The commands, despatched from Esa’s mission control centre in Darmstadt, Germany, tricked Pathfinder to reboot itself on to software that had already been corrupted.

It meant the gravity probe was locked down, unable to run its subsystems including its transmitter.

“The only way you could recover the spacecraft would be to go up there and attach an umbilical and restart from another computer,” explained Pathfinder’s spacecraft operations manager, Ian Harrison.

The kill procedure, more properly known as “passivating” the satellite, ensures there is no hazard to future missions through a collision or interference of radio communications.

The Darmstadt team in April had already fired the thrusters on Pathfinder to move it away from its station – a popular location for many Sun-studying missions.

It should now drift harmlessly around our star.

“There’s a very, very small chance it could return to the Earth-Moon system; it’s so remote but you can’t actually say it’s zero,” said Ian Harrison.

“The mission analysis actually looked at the planetary positions 500 years into the future.”


Gravitational waves – Ripples in the fabric of space-time

Image copyright
IGO/Caltech/MIT/Sonoma State

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Artwork: Two coalescing black holes spinning in a non-aligned fashion

  • Gravitational waves are a prediction of the Theory of General Relativity
  • It took decades to develop the technology to directly detect them
  • They are ripples in the fabric of space-time generated by violent events
  • Accelerating masses will produce waves that propagate at the speed of light
  • Detectable sources ought to include merging black holes and neutron stars
  • LIGO fires lasers into long, L-shaped tunnels; the waves disturb the light
  • LISA will fire lasers between three spacecraft separated by 2.5 million km
  • Detecting the waves opens up the Universe to completely new investigations

Gravitational waves are the big thing in science right now.

Ground-based laboratories in the US have recently begun detecting them from coalescing objects that are 20-30 times the mass of our Sun.

But by sending an observatory into space, scientists would expect to discover sources that are millions of times bigger still, and to sense their activity all the way out to the edge of the observable Universe.

It should significantly advance our understanding of gravity and how it works; and perhaps even highlight some chinks in Einstein’s so-far flawless equations.

LISA will detect gravitational waves by bouncing laser light between three spacecraft flying in a triangle formation, where the sides of the triangle are 2.5 million km long. The light beams will be measuring the precise positions of small, free-floating blocks inside the satellites.

When gravitational waves pass through the triangle, the distance between blocks of the different spacecraft should change by tiny amounts – just fractions of the width of an atom.


Laser science: Lisa Pathfinder’s technology demonstration

Image copyright
ESA

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A cutaway impression of the laser interferometer system inside Lisa Pathfinder

  • Lisa Pathfinder carried a laser interferometer to measure the behaviour of two free-falling blocks made from a platinum-gold alloy
  • Placed 38cm apart, these “test masses” were held inside cages that were engineered to insulate them against all disturbing forces
  • Whenever this super-quiet environment is maintained, the falling blocks should follow a “straight line” that is defined only by gravity
  • And it is under such conditions that a passing gravitational wave could be noticed by ever so slightly changing the blocks’ separation
  • Lisa Pathfinder demonstrated sub-femtometre sensitivity, but the satellite itself could not make a detection of the famous ripples
  • For that, a space-borne observatory would need to reproduce the same performance but with blocks positioned 2.5 million km apart
  • Lisa Pathfinder, however, proved the measurement principle and paved the way for the LISA mission’s selection by Esa nations

Image caption

The industrial production of LISA Pathfinder was led from the UK, at Airbus Defence and Space


LISA Pathfinder’s laser and gold-block monitoring system was shrunk down to fit inside a single satellite. As such, it could not itself detect gravitational waves, but the exquisite sensitivity of the instrumentation demonstrated that the metrology principles were sound.

“LISA Pathfinder did more than we ever asked for,” said Paul McNamara, Esa’s Pathfinder project scientist.

“It met its requirements on day one, the day we switched on its science. But we then met and surpassed the requirements of LISA. So, it’s been a phenomenal mission. It’s sad to turn Pathfinder off but at some point we have to look to the future,” he told BBC News.

Image copyright
Airbus DS

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Artwork: LISA envisages three spacecraft linked by laser arms that are 2.5 million km in length

Article source: http://www.bbc.co.uk/news/science-environment-40644104

Mighty T. rex ‘walked rather than sprinted’

T rex was a fierce carnivoreImage copyright
Getty Images

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T. rex was a fierce carnivore

The size and weight of a T. rex would have prevented it from moving faster than 20km/h (12mph), research suggests.

University of Manchester scientists used a new computer simulation to assess the speed of the massive biped.

Based on T. rex‘s muscles alone, the model came up with a maximum speed of 30km/h, but this dropped to 20km/h when skeletal strength was assessed too.

Had it moved from a brisk walk to a sprint, the dinosaur’s legs would have snapped under the weight of its body.

T. rex is everyone’s favourite dinosaur, and palaeontologists have been arguing for years about how fast it could run because this would tell us something about its hunting style and the way it caught its prey,” said Prof William Sellers.

”This project used a highly realistic computer simulation to predict how T. rex moved, and it shows that running would have been impossible because its skeleton just isn’t strong enough.

”That means that T. rex was actually quite slow and therefore not a pursuit predator.”

Hollywood makeover

Fossil footprints had already hinted that the mighty dinosaur was not as agile as its Hollywood image suggests.

However, Dr Eric Snively, of UW-La Crosse, US, who was not involved in the research, said it would still have been a scary creature.

The top speeds calculated for T. rex ”are still beyond those of most fast human joggers or distance runners and would be rather frightening to behold”, he said.

Referring to a scene in the sci-fi film, he added: ”It might well have caught Jeff Goldblum in Jurassic Park, had he stayed outside the Jeep and in the slippery mud.”

Image copyright
University of Manchester

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The research used sophisticated methods and tremendous computing power to calculate speeds

Prof Sellers said: “We can basically say that running was unlikely in any of the big predatory dinosaurs, but that doesn’t mean that the smaller ones were not fast.

“That means that as it grows up, T. rex would get larger and slower and we would expect to see the hunting behaviour change.

“This really helps fill out the picture of what life was like in the cretaceous [period], when we have large numbers of dinosaurs roaming around.”

The study is published in the journal Peer J.

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Article source: http://www.bbc.co.uk/news/science-environment-40632751

How did dogs become our best friends? New evidence

DogImage copyright
Getty Images

Dogs most likely evolved from wolves at a single location around 20,000 to 40,000 years ago, a study suggests.

Previously, it had been thought that dogs were tamed from two populations of wolves living thousands of miles apart.

Researchers studied DNA from three dogs found at archaeological sites in Germany and Ireland that were between 4,700 and 7,000 years old.

The ancient canines share ancestry with modern European dogs.

By looking at the rates of change to the DNA from the oldest specimen, scientists were able to place the timing of the domestication of dogs to between 20,000 and 40,000 years ago.

Krishna Veeramah of Stony Brook University in New York is a researcher on the study.

He said the process of dog domestication began when a population of wolves moved to the outskirts of hunter-gatherer camps to scavenge for leftovers.

”Those wolves that were tamer and less aggressive would have been more successful at this,” he explained.

“While the humans did not initially gain any kind of benefit from this process, over time they would have developed some kind of symbiotic relationship with these animals, eventually evolving into the dogs we see today.”

Image copyright
Amelie Scheu

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DNA was obtained from the skull of an ancient dog

The story of how dogs came to be tamed from wolves is complex and hotly debated.

Scientists believe dogs started moving around the world, perhaps with their human companions, about 20,000 years ago.

By 7,000 years ago, they were pretty much everywhere, although they were not the kind of dogs that we would consider pets.

”They would likely have resembled dogs we today call village dogs, which are free-breeding that did not live in specific peoples’ houses and have a similar look to them across the world,” said Dr Veeramah.

The dogs were later bred for their skills as hunters, herders or gundogs, eventually creating hundreds of modern breeds.

The research, published in Nature Communications, suggests even the dog breeds and village dogs found in the Americas and Pacific Islands are almost completely derived from recent European dog stock.

This is probably due to prolific dog breeding in Victorian times.

Image copyright
Timo Seregely

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The dog skull inside an ancient burial chamber

”In this regard, it appears therefore that our 7,000-year, Neolithic-old dog from Europe is virtually an ancestor to most modern breed dogs found throughout the world,” said Dr Veeramah.

”This ancestral relationship may even stretch back to the oldest dog fossil we know of, which is approximately 14,000 years old from Germany.”

Previous evidence suggested that the first domestic dogs appeared on opposite sides of the Eurasian continent more than 12,000 years ago.

Later, the eastern dogs moved with migrating humans and bred with those from the west, according to this theory.

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Article source: http://www.bbc.co.uk/news/science-environment-40638584

Why the cheetah is a champion sprinter

CheetahImage copyright
Getty Images

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The cheetah has a recorded speed of 68-75 mph (109.4-120.7 km/h)

They’re the sprinters of the animal world – cheetahs on land, falcons in the air and marlins in the sea.

But, why are they so fast when bigger, more muscular animals might be expected to outpace them?

Now, scientists have come up with a new theory to explain the gold medal-winning performance of animal athletes.

It appears it is all down to the energy required to get off the starting blocks.

“Scientists have long struggled with the fact that the largest animals are not the fastest,” said Prof Walter Jetz, from the US’s Yale University.

“In our work, we explain this with the simple fact that animals run out of readily mobilised energy before they are able to get their bodies to the maximum possible speed.

“So, while the largest animals in theory could be the fastest, the energy and time required to accelerate their larger bodies keep them from ever attaining it. “

The theory, outlined in the journal Nature Ecology Evolution, explains why lean, medium-sized animals are generally built for speed.

Image copyright
Getty Images

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The black marlin is one of the fastest fish species in the ocean

It applies to animals from fruit flies to blue whales and could even help predict the maximum running speed of animals that have long disappeared.

Results from the model were compared with data on hundreds of animal species, from flying animals to whales.

Researchers found the data generally fits with their predictions that maximum speed drops off sharply as animals grow beyond medium sizes.

“The theory is able to explain the maximum speeds of over 450 terrestrial, aerial and aquatic species varying from less than a gram to 10 tonnes in size,” said Prof Jetz, who worked on the study with colleagues at the EcoNetLab in Germany.

“It is also able to predict maximum speeds of long extinct species such as birds and dinosaurs.”

Speedy animals like the cheetah have evolved bodies primed to catch prey. They are the optimal size for maximum speed.

Accelerating takes a lot of energy, and muscles can only function at such intensity for a short time.

Thus, an elephant will never be able to overtake a cheetah because the fuel for acceleration (involving anaerobic respiration) will run out before it has reached its maximum (theoretical) speed.

The information will help scientists understand more about the ecology and behaviour of a species, including diet, hunting, migration and the search for a mate.

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Image caption

The peregrine is renowned for its speed, reaching more than 320 km/h (200 mph)

“The exciting part of this proposal is that it applies equally well to animals on land, in the air and in water,” write Australian scientists Peter Bishop and Christofer Clemente in a commentary in the journal.

“With this refined explanation of why animals move as fast as they do (or don’t), we can expect to gain further insight into how locomotion and ecology has evolved in various groups throughout the history of life.”

There are a few finer differences to iron out, however, including our own performance.

Humans fall short of the capability of our animal cousins of a similar size.

“In body mass, we humans are actually not too far from cheetahs,” said Prof Jetz.

“But obviously, being primates rather than part of the cats family, our body type has not, over millions of years, adapted to outrun fast prey.

“Our limbs and bipedal movement instead signal a less specialised diet and many other trade-offs that ultimately have us readily overtaken – or worse – by a lion or cheetah, whose body types are fully optimised for speed.”

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Article source: http://www.bbc.co.uk/news/science-environment-40632745