Chameleon colour not to blend in

The reptiles change colour for a variety of purposes - communication, camouflage and temperature control.

However, the reason why they first evolved this ability to flash bright colours was previously unclear.

Scientists report in the journal Plos Biology that it was to allow them to signal to other chameleons.

Co-author Dr Devi Stuart-Fox, from The University of Melbourne, Australia, told BBC News: "[Our research] suggests that chameleons evolved colour change for signalling, to fend off rivals or attract a mate, and not so they could match a greater variety of backgrounds."

Dr Stuart-Fox's team looked at the colour changing ability of 21 southern African dwarf chameleon species (Bradypodion spp), to compare species colour changing ability and consider evolutionary relationships.

As chameleons have a different visual system to humans, they have a fourth type of cone which is ultra-violet (UV) sensitive, the researchers had to first measure what the chameleons were actually seeing.

The Melbourne-based researcher explained: "We measured colour with a spectrometer, which measures both the UV and visual colour range, and combined this with information on the chameleon visual system to model chameleon colour perception.

By setting individual chameleons up in a duel with a series of opponents, the colour range between the submissive and dominant colours could be measured.

"If a male is challenged by another male they both begin by showing their brightest colours - until one figures out the other is going to win and changes to a submissive, dark, 'don't beat me up colour'," said Dr Stuart-Fox.

The team also looked at how chameleons change colour in response to a predator, by presenting them with a model bird or snake.

It was shown that the most dramatic colour changes were used to socially signal to other chameleons.

"We found that chameleon species that changed colour the most had displays that were most conspicuous to other chameleons. But they didn't have a greater range of background colours in their habitats

Asteroid makes close Earth pass

There was no chance of it hitting the planet, but astronomers trained telescopes and radar on the object to learn as much about it as they can.

The asteroid - which carries the rather dull designation 2007 TU24 - passed by at a distance of 538,000km (334,000 miles), just outside Moon's orbit.

Scientists who study so-called near-Earth objects say similar-sized rocks come by every few years.

The moment of closest approach for 2007 TU24 is 0833 GMT. The asteroid is only expected to be visible through amateur telescopes that are three inches (7.6cm) or larger.

Detailed observations of 2007 TU24 could reveal whether the asteroid is a solid object or simply a loose pile of space rubble.

Knowledge of how asteroids are put together will be key to working out how we might defend ourselves against future, more threatening rocks.

An explosive attack - so popular with Hollywood scriptwriters - may not be the most effective approach. Many scientists believe that giving a hostile object a gentle nudge over a long period of time may in fact be our best strategy.

Given the estimated number of near-Earth asteroids of this size (about 7,000 discovered and undiscovered objects, says the US space agency), an object similar to 2007 TU24 would be expected to pass this close to Earth, on average, about every five years or so.

The average interval between actual Earth impacts for an object of this size would be about 37,000 years, Nasa adds.

A little over a year-and-a-half ago, a 600m-wide (2,000ft) asteroid known as 2004 XP14 flew past the Earth at just about the Earth-Moon distance.

The asteroids' names include the year in which they were first identified.

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Zidane Wants To Return To Real Madrid

The French superstar met with president Ramón Calderón and sporting Pedja Mijatovic in the Spanish captial to discuss if there could be a role for him at the Bernabéu.

In a private meeting, Zidane met with the Madrid officials and was accompanied by his agent, Alain Migliacio, and explained hs desire to go back.

"I want to return to football to help in any way I can be useful and Madrid still feels like my home," AS quote him as saying.

Calderón was already aware of the Zidane's desire having spoken to him on the phone as the two have known each other since the midfielder's arrival from Juventus.

In an interview with L'Equipe recently, the 35-year-old said he wanted to be back in the game but did not know in what way.

While Madrid were considering him in a ambassadorial role, Zidane is reported to have told Calderón that he misses the day-to-day involvement and would like to coach the junior players.

Both his children play in the Madrid youth teams with Enzo in the Infantil B side and Luca learning the game in the Benjamin B team.

The suggestion that he could return to playing looks to have been dismissed as Zidane was linked with a move to Major League Soccer last year.

Bond may marry in next film

Gemma Arterton, who is starring in the next Bond film, has inadvertently revealed that the secret agent might get married.

Thesun.co.uk reports Arterton saying that she and Bond actor Daniel Craig were filming a scene in a honeymoon suite.

A shocked reporter immediately asked: "Honeymoon suite?" The embarrassed Arterton replied, "I think I've said too much."

Bond had got married in the 1969 hit On Her Majesty's Service, but his rival Blofeld killed the wife.

MARIA SHARAPOVA TO PLAY IN FED CUP

Russia tennis star Maria Sharapova along with members of the Russian team attend a press conference on Tuesday in Herzliya, prior to their Fed Cup match against Israel which will take place later this week in Tel Aviv. Australian Open champion Maria Sharapova committed herself to making her belated Fed Cup debut for Russia next weekend. The 20-year-old will spearhead the opening round of Russia's Fed Cup defence away to Israel in the February 2-3 World Group tie.

Snoring found to lead to bronchitis

People who snore are more likely to develop chronic bronchitis, the hacking cough most often associated with cigarette smoking or breathing polluted air, Korean researchers reported on Monday.

Why snoring might lead to bronchitis is not clear, said a team led by Inkyung Baik of Korea University Ansan Hospital in South Korea.

The report, published in the Archives of Internal Medicine, covered 4,270 men and women between 2001 and 2006. Of the group, 314 came down with chronic bronchitis.

"We collected information on snoring at baseline and identified incident cases of chronic bronchitis during a four-year follow-up period," Baik's team wrote.

After taking into account whether those in the study smoked or were otherwise at risk for bronchitis, the investigators concluded that people who snored five nights a week or less were 25 percent more likely to develop bronchitis than those who never snored.

The risk was 68 percent higher for those who snored six to seven times a week.

"Our findings provide support for the hypothesis that snoring is associated with chronic bronchitis," the researchers wrote.

It could be that snoring vibrates the upper airways, stressing them and leading to inflammation, the researchers said.