In just five decades, Brazil has lost 80 percent of the coral reef once found along 3,000 kilometers (1,864 miles) of its northeastern coast, according to a study cited by local media Sunday.

Brazil's reef ecosystems -- with 18 species of coral, algae and at least three types of fish -- lie not far out to sea, near major Brazilian cities like Fortaleza, Recife and Natal.

The U.S. space shuttle Endeavour took its final flight Friday, making a spectacular series of flypasts over California before landing in Los Angeles where it will retire near its birthplace.

Riding piggyback on a specially fitted Boeing 747, the shuttle flew over San Francisco's Golden Gate Bridge before heading south to take in the Hollywood sign and Disneyland, later landing at LA international airport (LAX).

Southern Africa's bushmen, and their relatives the Khoe, veered off on their own path of genetic development 100,000 years ago, according to a new study this week.

The split, gleaned from an analysis of genetic data, is the earliest divergence scientists have discovered in the evolution of modern humans.

Brazil, China, India and South Africa urged industrialized nations to commit to deeper cuts in greenhouse gas emissions at a United Nations meeting later this year.

Representatives from the four states, which along with Russia are part of the BRICS bloc of emerging nations, also dismissed current cuts by rich states as inadequate.

Psychopaths have a remarkably poor sense of smell, according to a study published on Thursday.

Researchers in Australia tested a theory that psychopathy -- a severe personality disorder characterised by lack of empathy, antisocial behaviour and callousness -- may be linked to impaired smell ability.

How does a tabby cat earn its stripes? With the right DNA.

Scientists say they've found the gene that sets the common tabby pattern — stripes or blotches.

The world's first flight powered entirely by bio jet fuel will take off next month from Ottawa, the fuel makers announced Thursday.

Applied Research Associates and Agrisoma Biosciences partnered with the National Research Council of Canada (NRC) to develop a "sustainable source of renewable energy" for the commercial airline industry.

The U.S. space shuttle Endeavour arrived Thursday in California, where it will make a spectacular series of flypasts before finally heading into retirement near where it was built.

Riding piggyback on a specially fitted Boeing 747, the shuttle landed at Edwards Air Force base north of Los Angeles after stopping overnight in Texas, while en route from Cape Canaveral, Florida.

NASA's Curiosity Rover will study its first martial rock Friday, more than a month after landing on the Red Planet, mission officials said.

Mars Science Laboratory project scientist John Grotzinger said the rover drove for another 100 feet (30 meters) last night, for a total travel distance of 950 feet so far.

Arctic sea ice has shrunk to its smallest surface area since record-keeping began, taking the world into "uncharted territory" as climate change intensifies, U.S. scientists warned Wednesday.

Satellite images show the ice cap has melted to 1.32 million square miles (3.4 million square kilometers) as of September 16, the predicted lowest point for the year.