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Category: Biology

Whether slow or fast, here’s how your metabolism influences how many calories you burn each day

Whether slow or fast, here’s how your metabolism influences how many calories you burn each day

Why does it seem like some people can eat anything and not gain a pound while others are the opposite? Heide Benser/The Image Bank via Getty Images Terezie Tolar-Peterson, Mississippi State University It’s a common dieter’s lament: “Ugh, my metabolism is so slow, I’m never going to lose any weight.” When people talk about a fast or slow metabolism, what they’re really getting at is how many calories their body burns as they go about their day. The idea is…

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How the first life on Earth survived its biggest threat — water

How the first life on Earth survived its biggest threat — water

Michael Marshall writes: On 18 February next year, a NASA spacecraft will plummet through the Martian atmosphere, fire its retro-rockets to break its fall and then lower a six-wheeled rover named Perseverance to the surface. If all goes according to plan, the mission will land in Jezero Crater, a 45-kilometre-wide gash near the planet’s equator that might once have held a lake of liquid water. Among the throngs of earthlings cheering on Perseverance, John Sutherland will be paying particularly close…

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How ‘neutral theory’ altered ideas about biodiversity

How ‘neutral theory’ altered ideas about biodiversity

Christie Wilcox writes: If you had braved the jungles of China’s Fujian province in the early 20th century, various accounts say you could have witnessed a stunningly unexpected animal: a blue tiger. These tigers were described as “marvelously beautiful” with bodies “a deep shade of Maltese, changing into almost deep blue on the under parts.” As late as the 1950s, hunters reported spotting their blue hairs alongside the traditional orange fur of other South China tigers on trails. Then the…

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Is the Earth an evolving organism?

Is the Earth an evolving organism?

W Ford Doolittle writes: Many of us, scientists included, harbour contradictory intuitions about Mother Nature. We can see that ecosystems often have an inherent ability to self-stabilise, and we know we wouldn’t be here if the planet hadn’t maintained conditions suitable for life for almost 4 billion years. One reaction is to claim that some Earth-wide equilibrium, though fragile, does exist, and reflects the fact that species have evolved to cooperate with one another. Another is to say that the…

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Study reveals connection between gut bacteria and vitamin D levels

Study reveals connection between gut bacteria and vitamin D levels

UC San Diego Health: Our gut microbiomes — the many bacteria, viruses and other microbes living in our digestive tracts — play important roles in our health and risk for disease in ways that are only beginning to be recognized. University of California San Diego researchers and collaborators recently demonstrated in older men that the makeup of a person’s gut microbiome is linked to their levels of active vitamin D, a hormone important for bone health and immunity. The study,…

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Did viruses create the nucleus? The answer may be near

Did viruses create the nucleus? The answer may be near

Christie Wilcox writes: Different as the cells from animals, plants, fungi and protozoa can be, they all share one prominent feature: a nucleus. They have other organelles, too, like the energy-producing mitochondria, but the presence of a nucleus — a well-defined porous pouch full of genetic material — is what inspired the biologist Édouard Chatton in 1925 to coin the term eukaryotes, which referred to living things with a “true kernel.” All the rest he labeled prokaryotes, for life “before…

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Where is the dividing line between you and the world

Where is the dividing line between you and the world

Frédérique de Vignemont and Colin Klein write: Heini Hediger, a noted 20th-century Swiss biologist and zoo director, knew that animals ran away when they felt unsafe. But when he set about designing and building zoos himself, he realised he needed a more precise understanding of how animals behaved when put in proximity to one another. Hediger decided to investigate the flight response systematically, something that no one had done before. Hediger found that the space around an animal could be…

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Tiny liquid droplets are driving a cell biology rethink

Tiny liquid droplets are driving a cell biology rethink

By Alla Katsnelson, Knowable Magazine, November 18, 2020 The fluid inside a living cell bustles with activity. Proteins, RNA, lipids and other molecules wiggle, zip, glide and drift through this broth — catalyzing reactions, activating receptors, relaying messages, marking viruses and other foreign molecules for destruction and performing a gazillion other tiny but crucial tasks. It all adds up to keep cells — and the life forms they’re a part of — running smoothly. Biologists have studied these cellular processes…

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How the gut protects the brain

How the gut protects the brain

Deborah Devis writes: The gut is well known for being the first line of defence against infection, but it seems it also protects our most important organ – the brain. According to surprising new research, antibodies that defend the perimeter of the brain are normally found in, and trained by, our gut. “This finding opens a new area of neuroimmunology, showing that gut-educated antibody-producing cells inhabit and defend regions that surround the central nervous system,” says Dorian McGavern from the…

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‘Pristine’ extraterrestrial organic compounds found on meteorite may shed light on origin of life on Earth

‘Pristine’ extraterrestrial organic compounds found on meteorite may shed light on origin of life on Earth

Vice reports: On a dark winter night in 2018, hundreds of people across the Great Lakes region witnessed a radiant meteor brighten the skies. Mere days after the fireball streaked overhead on that night in January, scientists were able to track down precious pieces of the ancient space rock using weather radar reports. The scattered remnants of the object, known as the Hamburg meteorite, contain a “high diversity” of extraterrestrial organic compounds that are preserved “in a pristine condition,” according…

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Migratory bird flies non-stop over 7,500 miles from Alaska to New Zealand

Migratory bird flies non-stop over 7,500 miles from Alaska to New Zealand

The Guardian reports: A bird said to have the aerodynamic build of a “jet fighter” has been tracked flying more than 12,000km (7,500 miles) from Alaska to New Zealand, setting a new world record for avian non-stop flight. The bar-tailed godwit set off from south-west Alaska on 16 September and arrived in a bay near Auckland 11 days later, having flown at speeds of up to 55mph. The male bird, known as 4BBRW in reference to the blue, blue, red…

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The blueprint for life, neatly folded

The blueprint for life, neatly folded

By Ivan Amato, Knowable Magazine, October 10, 2020 Squinting through his microscope at salamander cells, late-nineteenth-century biologist Walther Flemming spotted a curious substance deep inside the cells’ nuclei that selectively soaked up the stain he was using. The stuff looked like a skein of wool — until, that is, a cell underwent division. Then the skein separated into fatter, discrete threads: the chromosomes, Greek for “color bodies.” Flemming’s scientific descendants are still squinting, but with ever more powerful molecular, imaging…

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Humans are all more closely related than we commonly think

Humans are all more closely related than we commonly think

Scott Hershberger writes: The late esteemed English actor Christopher Lee traced his ancestry directly to Charlemagne. In 2010 Lee released a symphonic metal album paying homage to the first Holy Roman emperor—but his enthusiasm may have been a tad excessive. After all, says geneticist Adam Rutherford, “literally everyone” with European ancestry is directly descended from Charlemagne. The family tree of humanity is much more interconnected than we tend to think. “We’re culturally bound and psychologically conditioned to not think about…

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The fear of being eaten shapes brains, behavior, and entire ecosystems

The fear of being eaten shapes brains, behavior, and entire ecosystems

Lesley Evans Ogden writes: As high tide inundates the muddy shallows of the Fraser river delta in British Columbia, what looks like a swarm of mosquitoes quivers in the air above. Upon closer inspection, the flitting mass turns out to be a flock of small shorebirds. The grey-brown wings and white chests of several thousand Pacific dunlins move in synchrony, undulating low over the water, then rising up like a rippling wave, sometimes for hours on end. Staying aloft like…

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The molecular biologist, Jacques Monod, saw chance as one of the ‘secrets of life’

The molecular biologist, Jacques Monod, saw chance as one of the ‘secrets of life’

Sean B. Carroll writes: Jacques Monod arrived in Paris to some dreadful news. On June 5, 1944, four years into the German occupation of France during World War II, he was supposed to meet with fellow leaders in the French Resistance when his assistant, Geneviève Noufflard, told him that several commanders within the greater Paris region had just been caught by the Gestapo. Monod was pretty sure that at least one of those arrested knew about the rendezvous he was…

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Mysterious circles in the desert explained by the Turing pattern

Mysterious circles in the desert explained by the Turing pattern

Science Alert reports: It was 1952, and Alan Turing was about to reshape humanity’s understanding of biology. In a landmark paper, the English mathematician introduced what became known as the Turing pattern – the notion that the dynamics of certain uniform systems could give rise to stable patterns when disturbed. Such ‘order from disturbance’ has become the theoretical basis for all sorts of strange, repeated motifs seen in the natural world. It was a good theory. So good, in fact,…

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