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Antarctica's hottest day ever recorded

WorldㅣEnvironment

The temperature in northern Antarctica has hit 18.3C, thought to be a heat record on the continent best known for snow, ice and penguins. 

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The temperature was recorded on Thursday, February 6 at an Argentine research base and still needs to be verified* by the World Meteorological* Organisation. 

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“Everything we have seen thus* far indicates a likely legitimate* record,” Randall Cerveny, who researches records for the organisation, said in a statement. He added that he is waiting for full data to confirm. 

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The research base, called Esperanza, sits on a peninsula* that juts up towards the southern tip of South America. The peninsula has warmed significantly over the past half century — almost 3C, according to the World Meteorological Organisation. 

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Cerveny said the unusually high temperature was likely due, in the short term, to a rapid warming of air coming down from a mountain slope. 

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The previous record of 17.5C was set in March 2015.

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/Climate change is heating up Antarctica and the Arctic — the Earth’s polar regions — faster than other regions of the planet. 

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The Arctic is warming more than twice as fast as the rest of the globe, according to an annual report published in December by the US National Oceanic and Atmospheric Administration. There is no similar yearly report for Antarctica.

ANTARCTICA’S WEATHER The average annual temperature ranges from about −10C on the Antarctic coast to −60C at the highest parts of the interior. 

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Near the coast the temperature can exceed* 10C at times in summer and fall to below −40C in winter. Over the elevated inland, it can rise to about −30C in summer but fall below −80C in winter. 

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The lowest temperature ever recorded in Antarctica was at the Russian Vostok station, when temperatures dropped to -89.2C on July 21, 1983. This is the lowest temperature ever recorded on Earth.

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There is sometimes rain on the Antarctic coast but most precipitation* is in the form of snow or ice, equal to about 150mm of water a year. Wind gusts well over 200kmh have been recorded.

INTERMEDIATE

Fish with fingers missing link in evolution of human hand

WorldㅣScience

A fish with fingers that lurked in lagoons 380 millions years ago could teach us about the origins of the human hand. The 1.6m-long, shark-like Elpistostege watsoni was a slippery predator that lived in what is now eastern Canada. 

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Australian and Canadian scientists studying a fossil of the fish say its fin has similarities with the human hand, with the skeleton featuring an arm, a forearm and finger-like parts. Researchers say their findings reveal “extraordinary new information” about how the human hand evolved. 

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Professor John Long, of Flinders University, South Australia, said: “This is the first time that we have unequivocally* discovered fingers locked in a fin with fin-rays in any known fish. 

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“The articulating* digits in the fin are like the finger bones found in the hands of most animals. 

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“This finding pushes back the origin of digits in vertebrates to the fish level, and tells us that the patterning for the vertebrate hand was first developed deep in evolution, just before fishes left the water.” 

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Evidence of Elpistostege was first found in 1938 in the cliffs of Miguasha National Park in Quebec, Canada. It was only in 2010 a complete specimen was discovered.

The unique predator is believed to have lived in a shallow, tropical marine habitat with brackish* water in the Quebec region during the Middle and Upper Devonian period, about 393-359 million years ago. 

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Researchers believe fish such as Elpistostege are “transitional fossils” which could help understand how vertebrates, or backboned animals, were able to transition from water to land. 

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Palaeontologists* from Australia and Canada used high-energy CT scans to study the pectoral* fin, used to control the direction of movement. 

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The fin skeleton revealed the presence of an arm (humerus), a forearm (radius and ulna), a wrist (rows of carpus) and fingers (phalanges organised in digits). 

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Lead author, palaeontologist Dr Richard Cloutier, of the University of Quebec, Canada said humans come from a long line of evolution and “that every part of our body, like our fingers, has a long evolutionary history”. “This is true for Homo sapiens but it is also true for all living organisms,” Dr Cloutier added. 

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This marks the first time such traits have been found in a fish rather than in the earliest amphibians – the first land vertebrates – that later evolved from fish with sturdy fins like Elpistostege. It had two explicit* digits and three other apparent* digits. 

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“The origin of digits relates to developing the capability for the fish to support its weight in shallow water or for short trips out on land.” 

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He said the increased number of small bones in the fin created more flexibility to spread the fish’s weight out on dry land when not supported by the buoyancy of water. 

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The research was published in the journal Nature.

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