1 . Many people think of sharks as dangerous monsters. But human beings pose a far greater danger to these creatures than they do to us. Although shark attacks do occur, they are quite rare. On the other hand, according to one estimate, humans kill 100 million sharks every year. This statistics is a warning that many kinds of sharks may become extinct.

The killing of sharks is a problem for the whole planet. Sharks are apex predators, which means that they eat other species, but few creatures eat them. As sharks die off, the populations of animals that sharks consume will increase. This, in turn, means that the populations of the creatures that those animals eat will shrink. That includes some sea creatures that humans consume, such as shrimp. It also includes fish that eat algae, which can cause algae to spread so much that it damages coral reefs.

Reducing shark populations affect more than just the ocean. Ocean plants produce much of the oxygen on the planet. These plants can be harmed when changes in shark population upset the ecosystem.

Try to refuse shark products. Shark liver oil is used in many popular cosmetics. Pet foods, vitamins, energy drinks and leather goods can also be made from shark parts. And shark meat is sold around the world, sometimes under misleading names such as rock salmon or whitefish. Most sharks killed worldwide are hunted for their fins, which are used to make shark fin soup. The process is cruel: Fisherman cut the shark's fin off and then dump the shark back into the water, still alive. Then the shark dies slowly, sometimes over several days. Sharks breathe by swimming, so a shark that can't swim will die.

Sharks often die because they become tangled in nets meant for other kinds of fish. If you eat seafood, make sure it comes from fisheries that care for the oceans.

Many organizations try to protect sharks. They can teach you about these essential creatures and give more advice on how to keep them alive. These organizations also need your support to continue protecting these important creatures.

2 . A new study has found that cats can connect with people in the same way as dogs and children. In experiments in cats and humans, the researchers found that cats do show specific “attachment styles toward human caregivers”. This suggests that cats show some of the same social abilities that historically have only been linked to dogs.

In a statement, writers of the study said the evidence suggests that both cat and dog attachments to humans may represent the same kind of connection that exists between children and their caretakers. “Our study indicates that when cats live in a state of dependency with a human, that attachment behavior is flexible and the majority of cats use humans as a source of comfort.”

The researchers designed experiments similar to the methods used to measure human attachment behavior. For example, other studies have observed how babies react to being reunited with caregivers after being separated for short periods. In this experiment, adult and young cats first spent two minutes in a room with their caregivers. The cats then spent two minutes in the room alone, followed by a two-minute reunion period with the caregivers.

About 70 cats were studied. The behavior of the animals was observed by experts who divided them into two groups. Sixty-four percent were judged to be “securely attached” to caregivers, while 36 percent were found to be “insecurely attached” to caregivers.

The cats with secure attachments showed several signs “reduced stress” levels. These cats were found to be more comfortable and effectively balance their attention between the person and their surroundings. “The majority of cats use their owner as a source of security. Your cat is depending on you to feel secure when they are stressed out,” researchers said. They added that the results showed that the level of secure and insecure attachments in cats is very close to those measured in human babies. In humans, research has found that 65 percent of babies are also securely attached to their caregivers.

3 . Yong male songbirds usually learn their songs from adult songbirds. But when those young birds do not have older ones to teach them, they have less success attracting mates.

For five years, ecologist Ross Crates with Australian National University has studied the singing ability and mating success of birds called regent honeyeaters (王吸蜜鸟).

Male birds once formed large groups in the winter. Now they are spread out across the country, so many fly alone. That means fewer honeyeater adults are nearby during the young birds first year of life.

“Song learning in many birds is a process similar to humans learning languages—they learn by listening to other individuals,” said Crates.

“If you can’t listen to other individuals, you don’t know what you should be learning.”

Researchers found that a large number of male birds appear to be learning tunes only used by other species. About 12 percent of male regent honeyeaters end up producing versions of songs usually sung by friarbirds and lack-faced cuckoo shrikes, among other birds.

The scientists released their research in the publication Proceedings of the Royal Society B. They found that males who sang unusual songs were less successful in attracting mates.

Peter Marra is a conservation biologist at Georgetown University and was not involved in the study. He said, “This research suggests that the loss of a song language once the population reaches a very small size could accelerate their decline.”

Scott Ramsay is a behavioral ecologist at Wilfried Laurier University in Ontario, Canada. He was not involved in the research. He said the songs were like an advertisement: “When male birds sing, it’s like putting out an ad saying, ‘I’m over here...and I’m really interested in finding a partner.”

Ramsay added that female honeyeaters may not even recognize these unusual singers as possible mates, and so do not approach them. Or it could be that they approach, “but then things go wrong if the males do not behave as expected.”

5 . Australia, France or… Mars? When considering a place to emigrate to, Mars might not be the best choice in your list, but according to an online survey, more than one in ten of British would accept a one-way ticket there. Yes, you read that correctly —because the Mars One mission is looking to emigrate to Mars, the first voyagers will not be able to return back to Earth. The organizers suggest applicants think over their applications, because the agreement didn’t come with a return ticket. But still thousands of people agreed to it.

The Mars One aims to construct a human settlement on Mars. Thankfully, applications for the program are entirely voluntary and potential astronauts can back out at any time during the strict selection process.

In order to apply, the candidate must be over 18, have A2 English level and be adaptable and curious. The following selection process consists of four rounds.

The first round is an online application including general information and a one-minute video in which the applicant answers some given questions and explains why he or she should be among the first humans to set foot on Mars. At the end of the first round, a team of Mars One experts will decide which applicants will pass to the next round.

The remaining applicants must then provide a medical statement from their doctor stating that they have met all the requirements. Successful candidates will then be briefly interviewed by Mars One’s chief medical officer Norbert Kraft.

One-hundred healthy, smart candidates are then in the third round which will test their team work ability and communication skills through a series of group challenges.

The final part of the testing process is the ability to stay alone. Even the best astronauts in history can hardly enjoy the silent space. Following this challenge, the forty remaining candidates will be reduced to thirty who will then undergo the Mars Settler Suitability Interview. Following on from the first selection series, international crews of up to six groups of four will become full time employees of Mars One.