Bottlenose dolphins that have learnt to use sea sponges as hunting tools form cliques with others that do the same -- the first evidence of animal grouping based on mutual interest, a study said Tuesday.

The finding may represent the first known proof of cultural behavior in the animal kingdom, U.S.-based researchers wrote in a paper in Nature Communications.

A prominent U.S. skeptic of the human causes of climate change, Richard Muller, has reversed course and said on Monday that he now believes greenhouse gases are responsible for global warming.

"I was not expecting this, but as a scientist, I feel it is my duty to let the evidence change my mind," Muller, a professor of physics at the University of California, Berkeley, said in a statement.

The first signs of poison darts and beeswax used in tool making have been found in a South African cave, suggesting that a modern hunter-gatherer culture emerged earlier than previously thought.

Artifacts at the Border Cave, an archeological site on the border of Kwa Zulu Natal and Swaziland, have been reanalyzed and dated to 44,000 years ago, about twice as old as widely believed, said the research in the Proceedings of the National Academy of Sciences.

The notion that women and children are rescued first during a shipwreck is a myth, scientists said Monday after analyzing 18 maritime disasters that show men generally save themselves.

The sinking of the Titanic -- in which 70 percent of the women and children on board were saved compared to 20 percent of the men -- is a rare exception to the rule, said the study by Swedish researchers in the Proceedings of the National Academy of Sciences.

China will next year attempt to land an exploratory craft on the moon for the first time, state media reported, in the latest project in the country's ambitious space program.

China's third lunar probe will blast off in the second half of 2013, the state Xinhua news agency reported late Monday. Other reports said it would land and transmit back a survey of the moon's surface.

Scientists said Sunday they had unraveled the mechanism by which Earth-warming carbon is sucked deep into the Southern Ocean to be safely locked away -- a process that may itself be threatened by climate change.

Wind, eddies and currents work together to create carbon-sucking funnels, said the research team from Britain and Australia in a discovery that adds to the toolkit of scientists attempting climate warming predictions.

A sperm whale that was rescued and returned to sea after being stranded for four days in shallow waters off the coast of West Java in Indonesia has died, a rescuer said Monday.

Fishermen found the 11-metre (36-feet) whale in waters near the beach in Muara Gembong Sunday evening, "dozens of miles" from the Pakis Jaya beach where it had been stranded, said Benvika, a rescuer from the Jakarta Animal Aid Network.

Once the preserve of science fiction, increasingly sophisticated robotic devices are vying for a place side by side with humans in the real world.

At Italy's Sant'Anna university, a bionic arm commanded by the human brain or a limb extension that allows rescuers to lift rubble after earthquakes are just some of the futuristic innovations in the pipeline.

Beijing on Friday denied accusations of solar panel dumping, saying it hoped Chinese and EU manufacturers could negotiate an end to a dispute that threatens a trade war.

EU ProSun, a group of more than 20 European solar panel makers, suspects Beijing of providing their Chinese rivals with loans and other subsidies enabling them to sell their goods below cost.

A university study that claimed fracking for gas deep beneath the Earth's surface did not cause water contamination was led by a U.S. professor with financial ties to the gas industry, a watchdog group said Friday.

Lead author Charles "Chip" Groat, of the University of Texas, told reporters when the research on hydraulic fracturing was presented at a major science conference in Canada in February that the university had turned down all industry funds for the study.