why do polar bears not live in antarctica

Reputation: Polar bears are the friends of penguins Reality: As far as we can tell, polar bears and penguins have never met outside a zoo
My children have outgrown books in which polar bears and penguins inhabit the same page. But there is an alarming number of them out there and this is one biogeographical crime I cannot forgive. Polar bears live in the Arctic, near the North Pole. Penguins live on Antarctica and the neighbouring continents, near the South Pole. They are literally poles apart, so don't unite them in fiction just because they look cute together. If children's authors are looking for a "friend" for their polar bear protagonist, then how about a brown bear? There is little doubt that polar bears are a very recent offshoot from the brown bear lineage, though there is considerable debate over when this divergence took place. One analysis suggests that. Another places the division at. Either way, the polar bear is a remarkably recent evolutionary innovation. This much is clear from the fact that the two species are still reproductively compatible. When zoos have brokered a cross between a polar bear and a grizzly, they have been rewarded with cubs. These hybrid offspring, variously named "pizzlies" or "grolars", are often fertile themselves. Over the past decade, these beasts have occasionally cropped up in the wild too. For instance, in 2006. In 2010, a cross between a female pizzly and a male grizzly. This is compelling evidence that polar bears and brown bears can be friends, even if the level of intimacy might not be suitable for children. There are of course differences, the most notable being coat colour. The hairs of brown bears are pretty solid. It's been suggested that this unusual structure may prevent pigment-producing cells migrating into the hair shaft. The hollow structure of polar bear fur also led to the alluring idea that each strand might act like a fibre-optic cable, carrying warming ultraviolet light directly to the bear's pigmented skin. But when physicist Daniel Koon tested this idea in the 1990s, he found otherwise. "," he concluded in a 1998 paper.

If polar bears do not use their hollow hair shafts to harness the sun's energy, how do they survive the harsh Arctic environment? The answer is largely down to fat. Polar bears are so dependent on blubber in their diet it's of little surprise they have substantial stores of fat themselves, sometimes accounting for. In 2014, of the University of California, Berkeley and her colleagues looked for genetic differences between brown bears and polar bears. The levels of cholesterol in the polar bear's blood are "extreme". "," Lorenzen said in a statement. "It remains an enigma how polar bears are able to deal with such lifelong elevated levels of cholesterol," the authors wrote. The answer may have something to do with some genetic fine-tuning of the polar bear's cardiovascular function. How will polar bears rendezvous with their brown bear chums? They'll probably use their noses. With a rapidly warming Arctic, polar bears will have to move further afield to survive In 2014, scientists revealed that sweat glands on polar bears' feet leave, a lasting odour that other bears can detect. that could be used to track them, but it would not come as too much of a surprise. With a rapidly warming Arctic,. Whether they will encounter brown bears more often remains to be seen. But they still aren't going to run into any penguins. Could polar bears live just as well in Antarctica as they do in the north pole? They may well get by, but at least it would supply an answer to the age old question: if a polar bear had a fight with a group of penguins, who'd win? Richard Proctor, London SE13 A polar bear's diet is very varied, and includes seaweed, berries, small mammals and carrion, as well as its principal food source, ringed and bearded seals. Polar bears (Ursus maritimus) are very closely related to brown bears (Ursus arctos); it could be said they are just brown bears that have adapted to living in polar conditions. They have the same omnivorous, opportunistic approach to feeding.

The penguins and seals in the Antarctic have no natural predators to speak of when they are out of the water. As such, they would be easy meat if polar bears were introduced and could be driven to extinction as a consequence. With the penguins and seals scoffed, the by then enormous polar bear population would in turn crash and it would be highly unlikely that the few remaining bears would be able to find sufficient food to sustain themselves. In other words, any well-intentioned attempt to save polar bears by this means would be an unmitigated disaster. Terence Hollingworth, Blagnac, France Of course polar bears can live in Antarctica! In Biggles' Second Case (1948), Biggles and the boys are in the South Atlantic on the trail of rogue Nazi Captain von Schonbeck and his U-517. While searching for the missing Biggles and Ginger, their pals Algy and Bertie find blood on the ice, while a quarter of a mile away two polar bears are seen swimming away. "I don't think it's much use looking for bodies here", says Algy, leaping to the wrong conclusion as, needless to say, Biggles does win out in the end. However, the fate of the polar bears, or why they were there in the first place, isn't recorded. Oops, Capt WE Johns. Richard Pinder, Seaford, East Sussex Why not? After all, a bear called Paddington emigrated from darkest Peru to the northern hemisphere. Oliver Sheppard, Vincennes, France And anyway, why do we have polar bears in the Arctic and penguins in Antarctica? Glynne Rowlands, Wirral, Merseyside Early peoples such as the Vikings constructed ships that could cross oceans; why did they never attempt any form of aviation, such as sail planes or hang gliders? The ancient Indian religious writings known as the Vedas mention a type of flying machine called a vimana. There is no evidence that such a machine existed, although some writers (notably Erich von Daniken) have cited them as evidence of contact between early humans and extraterrestrials. In a similar vein, it was thought the famous Nazca lines in Peru, which were constructed around 2,000 years ago, must have been created by a people with access to flying machines.

This was because the geoglyphs can only really be appreciated from the air. However, subsequent research has shown they could still have been constructed without any need to monitor the work from a high altitude. Other researchers have claimed the Nazca people could have used hot air balloons in order to supervise the work, which would (theoretically) have been within their capability. Geoff Clifton, Solihull, West Mids The earliest known record of man-powered flight was in Greece. Sadly, the pilot, Icarus, was killed and his father, the designer Daedalus, never attempted further developments в although he is credited with building a maze on Crete for King Midas. Brian Robinson, Brentwood, Essex What phrase did we use for "it's a catch-22 situation" before Joseph Heller wrote the novel? Before "catch-22" caught on in the 1970s, we had a whole range of expressions. We used to say, "it's a double bind," "it's a cleft stick," "it's heads I win, tails you lose," "it's a case of damned if you do, damned if you don't," or "it's a Morton's Fork". The last was a reference to the notorious tax-assessment policy of Henry VII's chancellor, whereby, if a nobleman lived in great style, he was obviously rich, and if he didn't, he was obviously hiding his wealth, and in either case he would be taxed to the hilt. Hugo Barnacle, London NW5 Back in the 70s I met Joseph Heller at a party in New York and asked him what phrase he used before catch-22. He said, rather belligerently, "Catch-18". Sam White, Lewes, East Sussex Any answers? If heaven has angels playing harps, what is hell's official musical instrument? (Will not except bagpipes as an answer). Paul Deighton, Banbury, Oxon Is there anything useful that can be done with the ever increasing number of jellyfish found in our oceans? Eneas Mackintosh, Rome Send questions and answers to nq@theguardian. com. Please include name, address and phone number.

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