Why natures laziest animal is an evolutionary success story
The sloth is a candidate for nature’s most misunderstood animal. Saddled with a name that speaks of sin, the world’s slowest-moving mammal has been eternally damned for its lethargic lifestyle. “These sloths are the lowest forms of existence,” proclaimed the great French naturalist Georges-Louis Leclerc, Comte de Buffon. “One more defect would have made their lives impossible.”
He couldn’t have been more wrong. The sloth is a supreme survivor that has graced our planet for some 64 million years. A survey of a Panama rainforest in the 1970s found that an incredible one-third of the total mammalian biomass was made up of sloths. The secret to the sloth’s success is its lackadaisical nature. They are energy-saving icons, performing about 10 per cent of the physiological work of a mammal of similar size, and boasting a suite of ingenious adaptations that allow them to exist on as few as 160 calories a day.
1. CLAWS
この記事は BBC Earth の October 2018 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は BBC Earth の October 2018 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
World's First Malaria Vaccine
The World Health Organization’s director-general hails ‘historic moment’ as mass immunisation of African children begins
Is River Pollution Putting The Species In Jeopardy Again?
Ten years ago, it was jubilantly announced that o ers had returned to every county in England. But is river pollution putting the species in jeopardy again?
The Big Burnout
Long hours, low pay and a lack of appreciation — among other things — can make for a stressful workplace and lead to burnout. It’s something we should all be concerned about, because over half of the workforce reports feeling it
Putting Nature To Rights
More countries are enshrining the right to a clean environment into law. So if a company or government is impinging upon that right, you could take them to court
Mega Spaceship: Is It Possible For China To Build A Kilometre-Long Spacecraft?
Buoyed on by its successful Moon missions, China has launched a five-year study to investigate the possibility of building the biggest-ever spacecraft
Are We Getting Happier?
Enjoying more good days than bad? Feel like that bounce in your step’s getting bigger? HELEN RUSSELL looks into whether we’re all feeling more cheery…
“Unless the Japanese got the US off their backs in the Pacific, they believed they would face complete destruction”
Eighty years ago Japan’s surprise raid on Pearl Harbor forced the US offthe fence and into the Second World War. Ellie Cawthorne is making a new HistoryExtra podcast series about the attack, and she spoke to Christopher Harding about the long roots of Japan’s disastrous decision
Your Mysterious Brain
Science has mapped the surface of Mars and translated the code for life. By comparison, we know next to nothing about what’s between our ears. Over the next few pages, we ask leading scientists to answer some of the most important questions about our brains…
Why Do We Fall In Love?
Is it companionship, procreation or something more? DR ANNA MACHIN reveals what makes us so willing to become targets for Cupid’s arrow
Detecting the dead
Following personal tragedy, the creator of that most rational of literary figures, Sherlock Holmes, developed an obsession with spiritualism. Fiona Snailham and Anna Maria Barry explore the supernatural interests of Sir Arthur Conan Doyle