Sharks have survived some 400 million years on Earth. Could their longevity be due in part to an extraordinary resistance to cancer and other diseases? If so, humans might someday benefit from shark secrets—but leading researchers caution that today's popular shark cartilage "cancer cures" aren't part of the solution.

New research provides the first experimental evidence that hermaphrodite animals, like plants, focus resources on their male side during times of stress. Challenging environmental conditions have also been shown to affect the ratio of male to female offspring in non-hermaphroditic animals.

The world's oceans are in crisis. Pollution, overfishing, invasive species, habitat destruction are daily threats. Attention to marine conservation science lags far behind that paid to conservation of firm ground, says a scientist.

Scientists at the University of California in San Diego are studying ocean mixing at the Hawaiian Ridge, a 1,600-mile (2,600-kilometer) long chain of largely submerged volcanic mountains. Their findings may shed light on global climate and oceanic temperature variations.

Paleontologists are familiar with mostly gray and brown fossils, the color determined by the rock they are embedded in. Now scientists have found and described a spectacular beetle fossil that still retains bright blue metallic wing cases after 50 million years.

Humans and gorillas share much of the same genetic makeup—but that doesn't mean they always get along. Researchers in the dense forests of central Africa are working to bring the two together for ecotourism. Ensuring that the animals are worth more alive than dead may be their only shot at survival. This story airs on Ultimate Explorer, in the U.S. Sunday, 8 p.m. ET/PT on MSNBC.

A recent discovery that the so-called "fixed" hot spot of molten magma, which created the Hawaiian Islands, actually drifted southward between 81 and 47 million years ago and is causing geologists to revise their descriptions of the interior workings of the Earth.

A new species of dinosaur was announced by Indian and American scientists today: a 30-foot (9-meter), horned carnivore that hunted other dinosaurs 65 million years ago. The research was supported in part by the National Geographic Society. Includes a gallery of Rajasaurus images, charts, and maps.

Sky watchers are readying their telescopes for a close look at Mars. On August 27, the red planet will be the closest it's been to Earth in 60,000 years. Mark your calendar, because the next time Mars gets as close won't be until the year 2287.

Scientists ruled out green cheese several centuries ago. But while the composition of the moon hasn't been in doubt since the first lunar landings, the prime source of that material has. A new study suggests an answer based on analysis of Earth, moon, Mars, and meteorite rock samples.

According to the "small world" theory, you should be just six handshakes or e-mail messages away from Madonna, Tiger Woods, or Nelson Mandela. But can anyone in the world really reach anyone else through a chain of just six friends? Yes, say researchers at Columbia University. 

Decades of counting India's wild tiger population by studying pug (paw) marks in the earth have come to nil. Indian and U.S. researchers have concluded that the technique is misleading. The data collected in this way has led to wrong estimates of the size of the population of the country's wild tigers and, as a result, to "poor conservation practices," the experts say.

For years, scientists have been stumped as to how water striders, an insect commonly found on freshwater ponds, rivers, and lakes, "walk" on water. A team of researchers from MIT believed the insects rowed by novel means, and to prove their theory, they built an aluminum robot.

Twenty years ago, scientists discovered a hole in the Earth's ozone layer above Antarctica. The protective atmospheric layer showed signs of other widespread damage. Now after a decade-long ban on ozone-depleting chemicals, scientists report on the first hints of recovery.

The Southern Ocean ecosystem is threatened by overfishing, say scientists. The warning came at a major conference in London in July, with Antarctic researchers forecasting increased pressure on krill and fish stocks. They fear this could have a devastating impact on sea birds and marine mammals.