Boffins find mystery seafaring ancestor in the Philippines

London, June 04 (ANI): Anthropologists have discovered a foot bone during an excavation of Callao cave in Luzon, which has led to researchers’ claim that humans reached the islands off south-east Asia at least tens of thousands of years earlier than previously thought.

Armand Mijares of the University of the Philippines Diliman, and his colleagues insist the bone is definitely human, and they are provisionally calling it a lightly built modern human.

Mijares pointed out that its shape was unusual, and its size fell within the ranges of Homo habilis and Homo floresiensis.

It suggests that humans arrived on Luzon, the largest and northernmost major island in the Philippines, at least 67,000 years ago.

“The arrival of people in Australia 50,000 to 60,000 years ago is a good comparison,” New Scientist quoted expedition member Florent Detroit of the National Museum for Natural History in Paris, France, as saying.

“It seems coherent for us to think that in; south-east Asia and Australia, humans had sea-faring capabilities by 60,000 to 70,000 years ago.” (ANI)

Heartbeats tapped to generate power for implant

London, May 21 (ANI): A minuscule electricity generator implanted in the body could tap heartbeats to power an early-warning system for hypoglycaemia, or other medical conditions, according to a study.

A “nanogenerator” has been implanted in a live rat and has generated electricity from the animal”s beating heart.

And researchers led by Zhong Lin Wang at the Georgia Institute of Technology in Atlanta believe that it could run in-vivo sensors.

Wang knew that at the nanoscale carefully constructed wires of zinc oxide could act as piezoelectric materials – materials that convert mechanical energy into electricity.

Thus, he collaborated with colleagues to create a flexible generator that could harvest energy from natural actions such as breathing or heartbeats.

The team deposited zinc-oxide nanowires on a flexible polymer substrate that allows the nanowires to bend in a variety of ways.

They sealed the device in a polymer to shield it from body fluids and to ensure that any electricity they measured was generated by the device, not background interference.

This 2 millimetre by 5 millimetre rectangular device was then attached to a rat”s diaphragm muscle using tissue adhesive.

“The device is so tiny, you can barely see it by eye,” New Scientist quoted Wang as saying.

With each breath, the rat”s implant stretched and twisted, deforming the nanowires and generating up to 4 picoamps of current at a potential of 2 millivolts.

Then, the researchers implanted a similar device on a different rat”s heart, generating around 30 picoamps at 3 millivolts.

While the amount of energy generated is small, researchers are hopeful that they can scale up its output enough to power simple implantable nanosensors – blood pressure or glucose sensors, for instance – that have modest power requirements and don”t need a continuous supply.

Wang said that the device can capture motion in any direction, so it does not have to be fixed in a particular alignment.

“Any deformation can drive the device,” he added.

The study has been published in the journal Advanced Materials. (ANI)

Oldest mammalian hair found in France

London, May 20 (ANI): The oldest sample of mammalian hair has been found in a 100 million-year-old lump of amber.

The scales on the hair are similar to those found on the hairs of today”s mammals.

This may signify that the structure of mammalian hair has not changed for much of our evolution, according to Romain Vullo at the University of Rennes I in France, who discovered the hair.

“Perhaps mammalian hair does its job so well that it does not need to evolve,” New Scientist quoted him, as saying.

Vullo came across the amber-encased hair in the Font-de-Benon quarry in Charente-Maritime, southwestern France.

The site was a lush tropical forest around 100 million years ago.

The hair may have belonged to a small opossum-like animal.

Four teeth discovered in the same quarry suggest the animal may have been Arcantiodelphys marchandi, one of the oldest known marsupials. (ANI)

Friendly nose bacteria could wipe off MRSA

London, May 20 (ANI): Harmless bacteria from people”s noses could destroy MRSA, and could thus be transformed into nasal spray to mimic the immunity, which allows most of us who aren”t sick to fight off the superbug.

Takayuki Iwase and colleagues at Jikei University in Tokyo, Japan, said that Staphylococcus epidermidis can wipe out colonies of methicillin-resistant S. aureus (MRSA) in the lab.

Crucially, for the spray plan, S. epidermidis also cleared ordinary S. aureus in a bacterial “turf war” in the nose.

The friendly bugs oust their rivals with the help of an enzyme called Esp.

It”s possible either the enzyme, or live S. epidermis, could be used in hospitals.

Mark Enright of Biocontrol Ltd, a firm in Bedfordshire, UK, that is developing ways to pit harmless microbes against infectious ones, prefers using the live bacteria to the enzyme.

This is because the bacteria would continue growing in the nose and oust S. aureus permanently, whereas Esp alone would rapidly lose its activity.

“You would want them to knock out the opposition and take over,” New Scientist quoted Enright as saying.

He added that if a spray for MRSA can be developed the priority would be to treat the noses of all hospital staff since they can harbour and spread MRSA. (ANI)

Social network history can reveal your identity

London, May 19 (ANI): When you enrol yourself as a member on a social networking site, may be revealing more than you bargained for, an experimental website has proved.

The website has managed to identify the names of people who visit it, by harvesting information about the groups they belong to.

And the trick could act as the biggest tool for marketing teams and scammers.

The snooping site exploits the fact that your web browser keeps track of which web addresses you have visited.

Website owners can collect this information by hiding a list of web addresses in the code for their web page, reports New Scientist.

When someone accesses this page, their browser will tell the website owner which of the hidden addresses they have already visited.

Membership groups within social networks have distinct web addresses and the names of group members are publicly available.

Gilbert Wondracek at the Vienna University of Technology in Austria and his colleagues collected data on 6500 groups, containing 1.8 million users, on Xing, a business-oriented social network based in Hamburg, Germany.

On analysing the overlap between membership lists they estimated that 42 per cent of users could be uniquely identified by the groups they visit.

The researchers then built a website that read visitors” history of browsing Xing addresses.

When they asked 26 friends and colleagues who use Xing to try it, they were able to identify 15 of them.

Since Wondracek”s experiment, Xing has started adding random numbers to the addresses used to access its membership groups.

The Xing server ignores the extra numbers, but they confuse attacks by a site like Wondracek”s.

More complete protection may come in the next round of browser updates. The developers of Firefox, Chrome and Safari are working on fixes that will prevent browsing history being relayed back to website owners.

The study was presented at the IEEE Symposium on Security and Privacy in Oakland, California. (ANI)

Waking up ”sleeping” eggs may boost fertility

London, May 18 (ANI): Scientists in the US say that aging women or women who froze ovaries prior to cancer treatments may have a chance to have babies based on a novel method that can bring dormant reproductive cells into an active state.

Female mammals are born with millions of dormant eggs, but only a small fraction ever mature into cells with reproductive potential.

One factor keeping cells in this immature state is the PTEN gene, which suppresses a signalling pathway involved in cell growth.

As part of the study, Aaron Hsueh at Stanford University Medical School in California and his colleagues exposed mouse ovaries to a PTEN inhibitor and a molecule that stimulates the signalling pathway that PTEN inhibits, reports New Scientist.

Control ovaries remained untreated. The ovaries were then transplanted back into the mice, and they received a hormone to stimulate egg development.

Two weeks later, the treated ovaries contained two to six times as many mature follicles – which have the potential to release mature eggs – as the untreated ones.

Twenty healthy mouse pups were born after fertilised eggs from the treated ovaries were implanted into surrogate mothers.

Hsueh”s team has used a similar approach to stimulate fragments of human ovarian tissue. When these were implanted into mice, four times as many mature follicles were produced as in controls. But for ethical reasons, the eggs could not be fertilised.

The study has been published in the Journal Proceedings of the National Academy of Sciences. (ANI)

Bat fellatio study prompts sexual harassment row

London, May 18 (ANI): An academic at the University College Cork in Ireland found himself at the centre of a sexual harassment scandal after he discussed a scientific paper, titled ‘Fellatio in fruit bats prolongs copulation time’ with a female colleague.

Dylan Evans, a psychologist at the university”s school of medicine, has been saddled with a two-year period of intensive monitoring and counselling after discussing the paper with a colleague.

And now his university is coming under international pressure to lift the punishment meted out to Dylan.

As part of what he says was an ongoing discussion on human uniqueness, Evans showed a copy of the fellatio paper to a female colleague in the school of medicine.

“There was not a shred of a sign of offence taken at the time. She asked for a copy of the article,” New Scientist quoted Evans as saying.

A week later he got a letter informing him that he was being accused of sexual harassment.

Evans said that the whole case is “utterly bizarre”.

The complainant”s side of the argument is that she was “hurt and disgusted”, and asked Evans to leave a copy of the paper with her as way of cutting short the meeting.

Apparently, there was more to the grievance between Evans and the complainant than the fellatio paper incident, but an independent investigation found that Evans was not guilty of sexual harassment.

The investigation stated that it was reasonable for the colleague to have been offended and that showing the paper was a joke with a sexual innuendo, but that it was not Evans” intention to cause offence.

Nevertheless, the university”s president, Michael Murphy, imposed a censure, which Evans says has prevented him getting tenure.

An online petition calling on the university authorities to back down has been set up and has been signed by high-profile academics including philosopher Daniel Dennett of Tufts University in Medford, Massachusetts, and Steven Pinker of Harvard University.

Dennett called the punishment “an outrageous violation of academic freedom” and Pinker says the “absurd and shameful” judgment “runs contrary to the principle of intellectual freedom and freedom of speech, to say nothing of common sense”.

The paper, which was carried out by many popular journals, had a certain prurient interest, which was only heightened by an explicit video that went with itMovie Camera.

The Irish Federation of University Teachers has written to Murphy asking him to rescind the two-year period of monitoring. (ANI)

New fire-fighter system to prevent tunnel fire

London, May 16 (ANI): Experts are set to test a system that picks out cars and trucks at risk of catching fire before they enter a tunnel.

Engineers at Siemens in Germany will install their experimental system at Aubinger road tunnel near Munich this month.

Tunnel fires, in most cases, start when defects in a vehicle”s brakes or engine cause them to run dangerously hot, reports New Scientist.

The new system will look for hotspots on each vehicle by pointing infrared cameras at them 1 kilometre before the tunnel”s entrance.

The resulting images will be automatically compared with reference images for each vehicle type to identify signs of overheating in the brakes, tyres, engine or other components. Warned by an audible alarm, staff closer to the tunnel will then be able to pull over suspect vehicles for inspection.

Some of the loads carried by commercial vehicles can feed a fire once it starts.

A truck fire in the Mont Blanc road tunnel in the French Alps that killed 39 people in 1999 was made worse by the vehicle”s cargo of margarine also catching fire.

To deal with such situation in the future, Siemens is developing long-range battery-powered radio-frequency identification (RFID) tags that transmit details of what trucks are carrying to readers at the tunnel entrance.

It will help firefighters know precisely what hazards they are faced with, when fire breaks out. (ANI)

Fat lipped fish evolving at record speed

London, May 15 (ANI): In what could be called one of the fastest evolutionary change in an organism, fish in a remote crater lake in Nicaragua are developing a new physical feature— very fat lips.

It has taken the lake cichlids just 100 generations and as many years to evolve this feature.

Most estimates of how fast species evolve new features are based on models, which generally indicate that it could take up to 10,000 generations.

While some models suggest just tens of generations are enough, but such rapid change has never been documented before.

Axel Meyer at the University of Konstanz in Germany and his team say the fat-lipped fish occupy a different ecological niche from their thin-lipped cousins, despite living in the same lake, which fills a volcanic crater formed 1800 years ago.

They don”t eat the same diet nor do they like to mate with each other – though lab experiments show they can still interbreed.

Meyer said that the fact that they do not mate with each other in the wild suggests they are well on the way to becoming separate species.

The new variety have narrower, pointy heads, ideal for nibbling insects and larvae from crevices in the volcanic rock, and fat lips to cushion their ventures into the sharp crags.

The thin-lipped variety has sturdier jaws and extra teeth to crack the shells of the snails they feed on.

“When scientists catch incipient species in the process of divergence, it is important, because it is difficult to catch the process in action,” New Scientist quoted Todd Streelman of the Georgia Institute of Technology in Atlanta, who also studies cichlid evolution, as saying.

“This new work nicely matches theories developed in the 1990s suggesting that species could develop rapidly even when they share the same environment,” he added.

The study was published in the journal BMC Biology. (ANI)

Boffins create artificial skin graft that promises to make you sweat

London, May 15 (ANI): Scientists have produced artificial skin containing sweat glands.

The researchers, who tested it in mice, hope that, unlike conventional skin substitutes, the new skin will allow patients with large grafts to sweat to keep their bodies cool, reports New Scientist.

“This system promises to restore normal sweating activity,” says Xiaobing Fu of the Burns Institute of the General Hospital of the People”s Liberation Army in Beijing, China.

For the discovery, Fu and colleagues seeded beds of collagen with immature skin cells called keratinocytes. To this they added microspheres of gelatin whose surfaces were loaded with sweat-gland cells extracted from donated skin samples plus epidermal growth factor, which triggers cell growth. After two weeks, layers of skin containing gland-like islands had formed.

When this skin was grafted to wounds 3 millimetres square on the hindpaws of mice, healing was faster and more extensive than with conventional skin grafts, and the wounds had almost vanished after six weeks.

However, the boffins have not shown that the sweat glands actually produce sweat.

The development has been explained in Biomaterials. (ANI)

Bonding hormone-based nasal spray helps men recognise emotions

London, May 15 (ANI): A nasal spray made of the hormone vasopressin can help boost men’s ability to recognise the emotions of both happy and angry, say scientists.

However, the spray doesn’t improve males’ ability to detect emotions of the neutral, reports New Scientist.

Just like “cuddle chemical” oxytocin improves bonding, vasopressin too drives less cosy aspects of social behaviour, such as aggression.

In their study, Adam Guastella at the University of Sydney in Australia compared the ability of 24 men given the spray to recognise neutral, angry and happy faces with peers given a placebo spray.

The study has been published in Biological Psychiatry.

“There may be an application in people with inadequate recognition of social cues,” Guastella says. (ANI)

Monkeys” fighting behaviour could give insights into human wars

London, May 14 (ANI): A study on monkeys’ choices while deciding to fight or remaining at peace could help shed light on human wars, says a new study.

Competition for resources is often assumed to be a main cause of conflict in both humans and other animals, says Jessica Flack at the Santa Fe Institute in New Mexico, but that might be wrong, reports New Scientist.

“We find that fighting is based on memories of what other individuals did last,” she added.

The researchers analysed data from 160 days of field observations of a group of 84 pigtailed macaques at the Yerkes National Primate Research Center in Lawrenceville, Georgia.

The team paid particular attention to which animals fought and how long each fight lasted.

Instead of explaining the monkey”s fighting ways by dreaming up a strategy based, for example, on the reward value of winning a fight for food or a mate, the researchers decided to look for strategies suggested by the data alone.

They made no assumption about the reasons for the monkeys” behaviour and looked only at patterns of behaviour leading up to fights.

Thus, they could determine the relative importance of the factors that led up to a fight.

They found that the strategy that best explained involvement in a fight was one in which decisions were based on the presence or absence of pairs of other monkeys.

This suggests that social dynamics play a central role.

Flack said that previous work has shown that monkeys often react to changes in the social structure of their group.

A monkey might decide to fight because a rival was gaining dominance, for example, or to defend another monkey that they wanted to make into an ally.

The new finding that previous conflicts shape future decisions suggests that fights may not be directly linked to immediate competition for resources.

However, in the long term, the motivations behind the strategy are linked to the fight for status and the access to resources that status brings, said Flack.

A better understanding of the real-world strategies used by monkeys could help predict the shape of future conflicts. (ANI)

Breastfeeding mechanics revealed

London, May 13 (ANI): While breastfeeding, it may look like a baby is chewing on the mother”s nipple, but ultrasound images show that the infant actually removes milk by creating a vacuum – also known as sucking.

The finding holds significance as it could explain why some babies fail to take to the breast. It may also shed new light on why breastfeeding really can be a painful experience for some women.

“There have been two theories about how breast milk is expressed,” New Scientist quoted Donna Geddes of the University of Western Australia in Crawley, as saying.

“One is that the baby uses a peristaltic or compression motion to actually push the milk out of the nipple and breast. The other theory is that vacuum is primary in removing the milk,” Geddes added.

Until now, most studies examining the mechanics of breastfeeding have focused on bottle-feeding infants, or on old X-rays that were of poor quality.

Instead, Geddes and her colleagues combined ultrasound imaging of infants suckling on the breast with measurements of the strength of the vacuum created by the baby”s mouth in 20 infants aged 3 to 24 weeks as they breastfed.

“What we see is that when the tongue is lowered and the vacuum is applied, that”s when the milk is coming out of the breast, and that doesn”t involve any compression of the nipple,” Geddes said.

They also found that infants who struggled to breastfeed generated much weaker vacuums than successful breastfeeders.

This may explain why babies with a cleft palate often fail to breastfeed, as do premature babies: preterm infants don”t have strong enough mouth muscles to suck hard enough.

According to researchers, the next step is to devise a simple and universal test that could be used to assess babies” ability to suck. This could reassure mothers whose infants are struggling to feed that it”s not their fault, they said.

The research was presented at the Medela breastfeeding and lactating symposium in Venice, Italy. (ANI)

Study suggests Neanderthals not the only one humans bred with

London, May 13 (ANI): A new study has found that Neanderthals were not the only other Homo species early Homo sapiens mixed with.

João Zilhão at the University of Bristol, UK, suggests H. sapiens migrated from Africa to meet and interbred with other Homo species that have now become extinct.

Swedish biologist Svante Svante Pääbo”s team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany have found the first definitive evidence of interbreeding.

They reported last week that the genome of humans today is roughly 1 to 4 per cent Neanderthal.

The fact that all non-Africans have this percentage, suggests that H. sapiens and Neanderthals interbred sometime between 100,000 and 45,000 years ago, after the first humans left Africa but before they split into regional populations.

Another genetic study confirmed the suggestion made by Svante Pääbo”s team.

Jeffrey Long at the University of New Mexico in Albuquerque presented results from nearly 100 modern human populations at a meeting of the American Association for Physical Anthropologists in April.

The experts found proof that Eurasians became genetically diverse by breeding with other Homo species after they left Africa, reports New Scientist.

Also, they observed a spike in genetic diversity in Indo-Pacific peoples, dating to around 40,000 years ago. Again, it”s unlikely the diversity came from H. sapiens interbred with Neanderthals, as the latter never travelled that far south.

Meanwhile, Zilhão”s team in Portugal discovered the 25,000-year-old bones of a child they are convinced is a human-Neanderthal hybrid. Zilhão says fossils from Romania and the Czech Republic also bear Neanderthal features, though others dispute this.

Moreover, decorative artefacts characteristic of humans have cropped up at Neanderthal sites, dated to around the time of contact with humans in Africa and the Middle East. Further east, 40,000-year-old human bones from a cave near Beijing, China, have features that recall other Homo species, says Erik Trinkaus of Washington University in St Louis, Missouri.

In March, Pääbo”s team reported the discovery of DNA from a hominin that is probably neither human nor Neanderthal that lived 50,000 to 30,000 years ago in a cave in southern Siberia. They dubbed the creature X-woman, and sequencing machines are already decoding its genome, says Pääbo”s colleague Ed Green of the University of California, Santa Cruz.

Green does not wish to dismiss the idea that X-woman or its kind have bred with humans. (ANI)

Pyramids ”are most efficient shape for filling a container randomly”

London, May 13 (ANI): Pyramids are the best shape for packing candies, according to a new American research.

Graduate student Alexander Jaoshvili of New York University and his colleagues filled and shook containers of tetrahedral game dice.

The tetrahedra were packed tightly to occupy 76 percent of their containers, they found. In comparison, randomly packed spheres fill up to 64 percent of space, while squashed spheres, or ellipsoids, can fill as much as 74 percent.

The research can help develop stronger materials – MRI studies by the team demonstrate that a tetrahedral die can be locked into place by its immediate neighbours alone, making it harder to nudge out of place.

Jumbled collections of spheres, by contrast, are less rigid because any sphere can be moved by objects as far away as six diameters.

The finding can aid the development of nearly unbreakable plates.

“If, for instance, you wanted to make a very dense, rigid, hard ceramic, you would probably be better off making the powder from tetrahedra,” New Scientist quoted Jaoshvili”s adviser, Paul Chaikin, as saying.

According to Salvatore Torquato of Princeton University, tetrahedra may be able to pack together randomly even more efficiently.

In a recent simulation, Torquato and student Yang Jiao found a way to pack tetrahedra that took up more than 82 percent of space.

But this configuration may be more ordered than the one in Jaoshvili”s study.

The question is important as it”s still not known what kind of packing – random or ordered – is most efficient for tetrahedra.

Ordered, crystalline arrangements of tetrahedra can fill more than 85 percent of available space, recent simulations have found, but randomly assembled objects might be able to pack more tightly.

“Nobody knows whether the densest packing is ordered or random,” Chaikin said.

Torquato said: “People tend to think that the densest packings are always ordered, but there”s no fundamental reason why that has to be true.

“We can”t rule out the possibility that the densest packings of tetrahedra will be disordered.”

Jaoshvili”s study has appeared in the journal Physical Review Letters. (ANI)

Nanotube transistor may help humans bond with machines

London, May 13 (ANI): Scientists in the U.S. have taken a big step toward bridging the gap between the mind and the machine.

Using ATP – adenosine triphosphate, the molecular medium of energy exchange present in nearly all living cells – Aleksandr Noy at the Lawrence Livermore National Laboratory in California and colleagues have created a novel transistor that could allow electronic devices that can be hooked directly into the nervous system.

The new transistor is made up of a carbon nanotube, which behaves as a semiconductor, bridging the gap between two metal electrodes and coated with an insulating polymer layer that leaves the middle section of the nanotube exposed.

The entire device is then coated again, this time with a lipid bi-layer similar to those that form the membranes surrounding our body”s cells.

The team then applied a voltage across the transistor”s electrodes and poured a solution containing ATP and potassium and sodium ions onto the device.

This caused a current to flow through the electrodes – and the higher the concentration of ATP was, the more strongly current flowed.

The device responds in this way because the lipid bi-layer incorporates a protein that, when exposed to ATP, acts as an ion pump, shuttling sodium and potassium ions across the membrane.

“The ion pump protein is an absolutely critical element of this device. Each cycle, it hydrolyses an ATP molecule and moves three sodium ions in one direction and two potassium ions in the opposite direction,” New Scientist quoted Noy as saying.

This results in the net pumping of one charge across the membrane to the nanotube.

The build-up of ions creates an electric field around the exposed portion of the semiconducting nanotube, increasing its conductivity in proportion to the strength of the field. When the supply of ATP is reduced, ions leak back across the membrane and the flow of current through the transistor falls.

Noy has claimed that this is the first example of a truly integrated bioelectronic system.

“I hope that this type of technology could be used to construct seamless bioelectronic interfaces to allow better communication between living organisms and machines,” Noy said.

The study has been published in the Journal Nano Letters. (ANI)

Witness brain scan doesn’t help

London, May 12 (ANI): Monitoring brain activity of witnesses reveals no more than what they say they remember, a study has shown.

The study by Jesse Rissman and his team at Stanford University in California comes amid controversy over whether to admit functional MRI scans as evidence in US courts.

As part of their research, the team asked 16 volunteers to view 200 mugshots, reports New Scientist.

An hour later, they were again shown pictures of faces, some of which they had seen before and others that were new.

The researchers recorded fMRI scans of the volunteers” brains as they reported which faces they recognised.

While the brain scans matched the volunteers” decisions on whether the faces were familiar, they could not predict if the recollection was accurate.

The team also don”t know how easily a witness could cheat the system: remembering a recent event or fabricating a lie may look the same to the scanner.

The study has been published in the Journal Proceedings of the National Academy of Sciences. (ANI)

Now, a robot to hire, pay workers

The next step in the corporate world may just have been unveiled – the one where software is the ultimate arbiter.

Well, it could soon be a reality, for a web service has been launched software algorithms to automatically recruit, hire and pay workers to do a wide variety of tasks.

The website normally provides a forum for companies wanting to outsource their work.

Now it has been upgraded so that developers can write software to post job adverts on the site, take on respondents and pay them for the results without human input.

“For the last 60 years, humans have controlled software – now we”re getting to the stage where software can control humans,” New Scientist quoted Matt Barrie of Australian website Freelancer.com as saying.

For example, a program written for a store with a large inventory could automatically recruit salespeople to sell its products and send more work the way of people that do the best job.

As the software is doing the commissioning and assessing the results, it avoids the need for a company to hire other people to rate the work that was done.

Barrie said that there are enough programmers on the site”s books for it to be possible to write software that can even improve itself, by recruiting people to improve its own code.

Study sheds light on the evolution of lizards

London, May 10 (ANI): A new research has confirmed that competition, and not predation, is the primary selective force in island lizards.

In one of its kind ecological field experiment, entire islands in the Bahamas were wrapped with netting, snakes introduced to two other islands and the fitness of hundreds of lizards was measured using treadmills.

The research has resolved a long-standing question about the evolution of lizards.

As part of their research, Ryan Calsbeek and Robert Cox of Dartmouth College in Hanover, New Hampshire, excluded predators from two small, uninhabited islands in the Bahamas by wrapping the islands – about 1000 square metres each – with netting to keep out predatory birds. Meanwhile, they enhanced predation on two other islands by introducing lizard-eating snakes.

Also, they seeded one of each pair of islands with high densities of Anolis sagrei lizards, and the other with lower densities of the animals.

Before release, they marked and measured each one and tested its stamina by running it to exhaustion on a treadmill.

“Your Lance Armstrong lizards can run about 7 minutes. Your overweight field-biologist lizard runs for about 2 minutes. We spent several hours a day just running the animals, and we did that day in and day out for several weeks,” New Scientist quoted Calsbeek, as saying.

After a period of four months, the experts returned to the island and recaptured every remaining lizard.

Larger, longer-legged and higher-stamina lizards had survived better than smaller, wimpier ones on higher-density islands where competition was more intense, they found.

However, these traits did not affect the chance of survival in the face of predation. This supports the idea that competition, and not predation, is the primary selective force in these island lizards, says Calsbeek.

David Reznick, an evolutionary biologist at the University of California, Riverside, said: “To me, that”s surprising. I would have thought that predation would matter.”

The study has been published in the Journal Nature. (ANI)

Protein jab mends broken bones

London, May 10 (ANI): Scientists have found a novel way to significantly speed up the healing of broken bones in mice, a feat which, if replicated in humans, could mean people with fractures would be free of their casts a lot sooner.

Jill Helms, Roel Nusse and team at Stanford University in California drilled small holes into the shin bones of mice, and injected them with Wnt proteins.

These proteins prompt bone stem cells to divide, reports New Scientist.

Three days later, bone growth was three times greater than in mice injected with a placebo, it was observed.

The approach could prove to be better than adding new stem cells, which can divide uncontrollably.

The research has appeared in the journal Science Translational Medicine. (ANI)