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กำลังแสดงโพสต์จาก กันยายน, 2019

Warming oceans killing coral reefs

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Warming oceans killing coral reefs Warming oceans killing coral reefs Coral reefs around the world are experiencing a massive die-off that could be the worst in recorded history, a new study warns. Stoked by climate change and a powerful El Ni?o, record-high ocean temperatures have triggered the global event, which began last year and is expected to destroy 5% of the world’s coral reefs by 2016. The temperature changes brought about a phenomenon known as bleaching, in which corals expel symbiotic algae that provide essential nutrients, causing the brilliantly coloured reefs to turn ghostly white. A resilient reef can recover if water temperatures return to normal quickly, but if algae loss is prolonged, the coral eventually dies. Two similar global events took place in 1998 and 2010, but researchers predict the current one is likely to be more persistent – and deadly. This year as many as 95%of all US coral reefs are expected to see ocean temperatures that can lead to bleaching. Of

Microbe may be missing link in the evolution of complex life

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Microbe may be missing link in the evolution of complex life IT’S ONE OF the most fundamental questions in science: how did complex life evolve? Now, a team from Uppsala University in Sweden has moved one step closer to the answer after discovering a new group of microorganisms that represents a missing link in the evolution from simple to complex cells. Dubbed Lokiarchaeota, or ‘Loki’ for short, the microbe was found in Loki’s Castle, a 2,350m-deep hydrothermal vent located between Norway and Greenland. All organisms on Earth are either prokaryotes , such as bacteria, which have simple cells, or eukaryotes, such as mammals, which have more complex cells. However, as the two cell types are so different in composition, biologists have long wondered how one evolved from the other. “The puzzle of the origin of the eukaryotic cell is extremely complicated, as many pieces are still missing. We hoped that Loki would reveal a few more pieces of the puzzle, but when we obtained the fir