Bowhead whales (弓头鲸) can live 200 years or longer. How they do it is no longer among the secrets of the deep.

Scientists have mapped the genetic code of this long lived whale species. The international effort found unusual features in the Arctic whale’s genes. Those features likely protect the species against cancer and other problems related to old age. The researchers hope their findings will one day translate into ways to help people too.

“We hope to learn what is the secret of bowhead whales living longer, healthier lives,” says Joao Pedru de Magalhes. He is a gerontologist at the University of Liverpool in England. (Gerontology is the scientific study of old age. ) He is also a co-author of the study that appeared in Cell Reports. His team hopes, he says, that its mew findings might one day be used to improve human health and preserve human life.

Dr. Magalhäes’ team wanted to understand how the bowhead can live so long. To find out this, the experts analyzed the animal’s complete set of genes, called its genome (基因组). Those instructions are coded in the animal’s DNA. The team also compared the whale’s genome to that of people, mice and cows.

The scientists discovered differences, including mutations (变异), in the whale’s genes. Those changes are linked to cancer, aging and cell growth. The results suggest that the whales are better than humans at repairing their DNA. That’s important because damaged or flawed DNA can lead to disease, including some cancers.

Bowhead whales are also better at keeping abnormally dividing cells in check. Together, the changes appear to allow bowhead whales to live longer without developing age related diseases such as cancer, said Magalhäes.

Not so long ago, a sailor sailing across the cold waters of the northern Pacific Ocean might have had every chance of meeting a sea cow. This cow would have measured 10 meters long and weighed between five and 10 tons and it would spend most of its day moving slowly in the seas, eating grass growing underwater. The cow in question was known as Steller’s sea cow, which has now died out.

Today, many people don’t know that such a strange creature once existed, or don’t know its unbelievable story. but many scientists have discovered many fundamental facts about this mystical (神秘的) animal.

Surprisingly, the first recorded sighting of a Steller’s sea cow didn’t happen until 1741. When a sailing expedition (探险) was stuck on an uninhabited island, later named Bering Island. The sailors survived by hunting and eating the enormous sea cow. Like its modern relatives, the sea cow lived in groups. That and its slow moving behavior made it easy to be caught.

Those sailors that escaped from the island spread word of the amount of meat to be found off its shore. As a result, more and more people came to hunt the animals. It is said that one sea cow could feed 33 men for a month.

However, just 27 years after the island and species had been discovered by modern man, the last sea cow was reported killed. This makes the sea cow one of the few truly large mammals known to have been driven extinct in the modern age.

For those of us who have ever been to Ocean Park, the best part was probably seeing the beautiful and friendly dolphins. And the luckier people among us may have even had the chance to swim with these amazing creatures. At the same time, however, we can’t help but think that these animals would be happier in the wild, rather than be forced to perform for humans in captivity (圈养).

According to a recent study though, we needn’t think like that. The study, which was published in the journal Applied Animal Behaviour Science, was led by scientist.

As the first of its kind, the study’s aim was to look at captivity from the animals’ point of view, according to BBC News. Over the course of three years, Clegg and her team put together a series of experiments to figure out how captive dolphins felt about their lives. “We wanted to find out what activities in captivity they like most,” she told BBC News.

There were three kinds of experiment : one in which the dolphins were let alone, one in which toys were added to their pool, and one in which a human played with the dolphins.

It was found that of the three types of experiment, the dolphins seemed to enjoy playing with humans the most. “Their leaping from the water during training and their curious approaches to the edge of the pool appeared to be enthusiastic,” wrote BBC News science correspondent Victoria Gill. However, this doesn’t necessarily mean dolphins are happier in captivity than they are in the wild.

According to wildlife and nature platform One Green Planet, being raised in captivity could actually be harmful to dolphins. “By being born into captivity, they will never learn the skills necessary to survive in the wild. This means that any animal that is born in captivity can never be sent back into the wild,” it wrote on its website.

But while this may be true, at least it seems that captive dolphins still enjoy happy moments with humans.