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Category: Evolution

Cats’ genomes are surprisingly similar to humans’

Cats’ genomes are surprisingly similar to humans’

Katherine J. Wu writes: The genome of a mouse is, structurally speaking, a chaotic place. At some point in its evolutionary past, the mouse shuffled its ancestral genome like a deck of cards, futzing up the architecture that makes most other mammalian genomes look, well, mammalian. “I always consider it the greatest outlier,” Bill Murphy, a geneticist at Texas A&M University, told me. “It’s about as different from any other placental mammal genome as you can find, sort of like…

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As little as 1.5% of our genome is ‘uniquely human’

As little as 1.5% of our genome is ‘uniquely human’

Live Science reports: Less than 10% of your genome is unique to modern humans, with the rest being shared with ancient human relatives such as Neanderthals, according to a new study. The study researchers also found that the portion of DNA that’s unique to modern humans is enriched for genes involved with brain development and brain function. This finding suggests that genes for brain development and function are what really set us apart, genetically, from our ancestors. However, it’s unclear…

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DNA has four nucleotide bases. Some viruses swap in a fifth

DNA has four nucleotide bases. Some viruses swap in a fifth

Jordana Cepelewicz writes: All life on Earth rests on the same foundation: a four-letter genetic alphabet spelling out a repertoire of three-letter words that specify 20 amino acids. These basic building blocks — the components of DNA and their molecular interpreters — lie at biology’s core. “It’s hard to imagine something more fundamental,” said Floyd Romesberg, a synthetic biologist at the pharmaceutical company Sanofi. Yet life’s foundational biochemistry can be full of surprises. A few decades ago, researchers found viruses…

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When bacteria kill us, it’s more accident than assassination

When bacteria kill us, it’s more accident than assassination

Ed Yong writes: The classic novel by H G Wells, The War of the Worlds (1898) – a tale of England besieged by Martian conquerors – ends not with a rousing and heroic victory but an accidental one. The aliens subjugate humanity with heat rays and black smoke but, at the height of their victory, they die. Their machines come to a standstill amid the ruins of a deserted London, and the birds pick at their rotting remains. The cause…

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‘Social’ mitochondria, communicating between cells, influence health

‘Social’ mitochondria, communicating between cells, influence health

Katarina Zimmer writes: During his doctoral research on the ties between aging and mitochondria, Martin Picard frequently saw micrographs of those energy-producing organelles. Yet it wasn’t until fairly late in his graduate work that he first watched sped-up video of mitochondria moving inside live human cells, and the sight came as a revelation. Tagged with fluorescent dye, the mitochondria were neon squiggles crawling through the soupy interior of the cells — stretching and contracting, fusing together and splitting up again,…

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Beyond coronavirus: the virus discoveries transforming biology

Beyond coronavirus: the virus discoveries transforming biology

Nature reports: Mya Breitbart has hunted novel viruses in African termite mounds, Antarctic seals and water from the Red Sea. But to hit pay dirt, she has only to step into her back garden in Florida. Hanging around her swimming pool are spiny-backed orbweavers (Gasteracantha cancriformis) — striking spiders with bulbous white bodies, black speckles and six scarlet spikes that make them look like a piece of medieval weaponry. Even more striking for Breitbart, a viral ecologist at the University…

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Discovery of ‘Dragon Man’ skull in China may add species to human family tree

Discovery of ‘Dragon Man’ skull in China may add species to human family tree

The New York Times reports: Scientists on Friday announced that a massive fossilized skull that is at least 140,000 years old is a new species of ancient human, a finding that could potentially change prevailing views of how — and even where — our species, Homo sapiens, evolved. The skull belonged to a mature male who had a huge brain, massive brow ridges, deep set eyes and a bulbous nose. It had remained hidden in an abandoned well for 85…

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A mysterious crater’s age may add clues to the dinosaur extinction

A mysterious crater’s age may add clues to the dinosaur extinction

The New York Times reports: Some 65 million years ago, a rock from outer space slammed into Earth, wreaking havoc on life in its wake and leaving a large crater on our planet’s surface. No, it’s not the one you’re thinking of. Boltysh crater, a 15-mile-wide formation in central Ukraine, may not be as famous as the Chicxulub crater under the Yucatán Peninsula in Mexico, which is directly implicated in the death of the dinosaurs and many other species about…

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The day the dinosaurs died

The day the dinosaurs died

Douglas Preston writes: If, on a certain evening about sixty-­six million years ago, you had stood somewhere in North America and looked up at the sky, you would have soon made out what appeared to be a star. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. That’s because it was not a star but an asteroid, and it was headed directly for Earth at about forty-five thousand…

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No one knows how often DNA jumps between animal species

No one knows how often DNA jumps between animal species

Christie Wilcox writes: To survive in the frigid ocean waters around the Arctic and Antarctica, marine life evolved many defenses against the lethal cold. One common adaptation is the ability to make antifreezing proteins (AFPs) that prevent ice crystals from growing in blood, tissues and cells. It’s a solution that has evolved repeatedly and independently, not just in fish but in plants, fungi and bacteria. It isn’t surprising, then, that herrings and smelts, two groups of fish that commonly roam…

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Is a revolution brewing in evolutionary theory?

Is a revolution brewing in evolutionary theory?

Kevin Laland writes: When researchers at Emory University in Atlanta trained mice to fear the smell of almonds (by pairing it with electric shocks), they found, to their consternation, that both the children and grandchildren of these mice were spontaneously afraid of the same smell. That is not supposed to happen. Generations of schoolchildren have been taught that the inheritance of acquired characteristics is impossible. A mouse should not be born with something its parents have learned during their lifetimes,…

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Life deep underground and inside other worlds

Life deep underground and inside other worlds

Jordana Cepelewicz writes: Scientists poke and prod at the fringes of habitability in pursuit of life’s limits. To that end, they have tunneled kilometers below Earth’s surface, drilling outward from the bottoms of mine shafts and sinking boreholes deep into ocean sediments. To their surprise, “life was everywhere that we looked,” said Tori Hoehler, a chemist and astrobiologist at NASA’s Ames Research Center. And it was present in staggering quantities: By various estimates, the inhabited subsurface realm has twice the…

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The ‘dark matter’ inside your gut

The ‘dark matter’ inside your gut

Jonathan Jarry writes: There is a kind of dark matter inside our intestinal tract. “Dark matter” is the phrase coined for the matter that is implied to be present in the universe based on physicists’ calculations but that cannot be seen yet. Scientists who study tiny living things are facing their own type of dark matter: invisible microbes that are indirectly detected. They call it “microbial dark matter.” Much has been written about the bacteria that live inside our gut….

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Sleep evolved before brains. Hydras are living proof

Sleep evolved before brains. Hydras are living proof

Veronique Greenwood writes: The hydra is a simple creature. Less than half an inch long, its tubular body has a foot at one end and a mouth at the other. The foot clings to a surface underwater — a plant or a rock, perhaps — and the mouth, ringed with tentacles, ensnares passing water fleas. It does not have a brain, or even much of a nervous system. And yet, new research shows, it sleeps. Studies by a team in…

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Neanderthals carb loaded, helping grow their big brains

Neanderthals carb loaded, helping grow their big brains

Science reports: Here’s another blow to the popular image of Neanderthals as brutish meat eaters: A new study of bacteria collected from Neanderthal teeth shows that our close cousins ate so many roots, nuts, or other starchy foods that they dramatically altered the type of bacteria in their mouths. The finding suggests our ancestors had adapted to eating lots of starch by at least 600,000 years ago—about the same time as they needed more sugars to fuel a big expansion…

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Is music what makes us human?

Is music what makes us human?

Kevin Berger writes: In the past two years, the debate over whether music is universal, or even whether that debate has merit, has raged like a battle of the bands among scientists. The stage has expanded from musicology to evolutionary biology to cultural anthropology. This summer, in the journal Behavioral and Brain Sciences, more than 100 scholars sound off on evolution and universality of music. I love the din. The academic discord gives way to a symphony of insights into…

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