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Category: Evolution

A cell that lacks any metabolic genes is a new addition to the spectrum of life

A cell that lacks any metabolic genes is a new addition to the spectrum of life

Jake Buehler writes: Life’s fundamental structure is the cell, and so the main things that a cell does — processing biomolecules, growing, replicating its genetic material and producing a new body — are considered hallmarks of life. But earlier this year, scientists discovered a cell so severely stripped of essential functions that it challenges biologists’ definitions of what counts as a living thing. The species is a single-celled organism known only by the mysterious sequence of its genetic code. Its…

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The evolving science of dietary restriction

The evolving science of dietary restriction

Andrew Steele writes: The idea that eating less might make us live longer has been around for thousands of years. Even Hippocrates, the Ancient Greek physician, argued that, “When a patient is fed too richly, the disease is fed as well. Any excess is against nature.” Scientists have now spent decades testing whether his advice holds true. The first striking evidence came in the 1930s, when American nutritionist Dr Clive McCay found that rats fed a restricted diet lived almost…

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What is sleep?

What is sleep?

Vladyslav Vyazovskiy writes: After decades of research, there is still no clearly articulated scientific consensus on what sleep is or why it exists. Yet whenever sleep comes up as a topic of discussion, it is quickly reduced to its necessity and importance. Popular media remind us of what can, and will, go wrong if we do not sleep enough, and serve up some handy tips on how to overcome insomnia. Discussed exclusively in utilitarian terms, we are force-fed the idea…

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Tiny tubes in primitive Asgard archea may have been the precursor of our own cellular skeletons

Tiny tubes in primitive Asgard archea may have been the precursor of our own cellular skeletons

Veronique Greenwood writes: In 2010, biologists made a shocking discovery. Living in the mud of the North Sea were microorganisms whose genes looked a lot like ours. Genetic analysis revealed that humans, oak trees, blue whales — any living things whose cells have nuclei and mitochondria — are related to these microbes, which were named the Asgard archaea after the home of the Norse gods. Two billion years ago, it was an ancestor of an Asgard that diverged from its…

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The sudden surges that forge evolutionary trees

The sudden surges that forge evolutionary trees

Jake Buehler writes: Over the last half-billion years, squid, octopuses and their kin have evolved much like a fireworks display, with long, anticipatory pauses interspersed with intense, explosive changes. The many-armed diversity of cephalopods is the result of the evolutionary rubber hitting the road right after lineages split into new species, and precious little of their evolution has been the slow accumulation of gradual change. They aren’t alone. Sudden accelerations spring from the crooks of branches in evolutionary trees, across…

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Here’s how the first proteins might have assembled, sparking life

Here’s how the first proteins might have assembled, sparking life

Science reports: Life today depends on proteins, cellular workhorses that do everything from flex muscles to ferry oxygen. And proteins, in turn, depend on RNA, which carries the recipes for making them and also helps with their assembly. In modern cells, large protein-based enzymes help connect RNA snippets to amino acids, the building blocks of proteins. Then, the RNA- and protein-based cellular machine called the ribosome stitches the amino acids together into a protein chain, reading the correct sequence from…

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DNA from extinct hominin, the Denisovans, may have helped ancient peoples survive in the Americas

DNA from extinct hominin, the Denisovans, may have helped ancient peoples survive in the Americas

University of Colorado at Boulder: Thousands of years ago, ancient humans undertook a treacherous journey, crossing hundreds of miles of ice over the Bering Strait to the unknown world of the Americas. Now, a new study led by the University of Colorado Boulder suggests that these nomads carried something surprising with them—a chunk of DNA inherited from a now-extinct species of hominin, which may have helped humans adapt to the challenges of their new home. The researchers published their results…

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Life on Earth emerged fast — far quicker than we thought

Life on Earth emerged fast — far quicker than we thought

Michael Marshall writes: Here’s a story you might have read before in a popular science book or seen in a documentary. It’s the one about early Earth as a lifeless, volcanic hellscape. When our planet was newly formed, the story goes, the surface was a barren wasteland of sharp rocks, strewn with lava flows from erupting volcanoes. The air was an unbreathable fume of gases. There was little or no liquid water. Just as things were starting to settle down,…

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How animals heal themselves

How animals heal themselves

Emory University: In 2010, Emory biologist Jaap de Roode published the discovery that monarch butterflies use medicine to cure their offspring of disease. His lab revealed how, if infected with a parasite, the female butterflies prefer to lay their eggs on a species of milkweed containing higher levels of a toxic chemical. The caterpillars eat the milkweed, ingest the toxin, and reduce the parasite load in their bodies. With that finding, de Roode joined the vanguard of scientists uncovering how…

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The psychology of belief explains America’s ongoing war against evolution

The psychology of belief explains America’s ongoing war against evolution

By Edward White, Kingston University One hundred years after a Tennessee teacher named John Scopes started a legal battle over what the state’s schools can teach children, Americans are still divided over evolution. Scopes was charged with violating Tennessee law by teaching evolution, in a highly publicised July 1925 trial that led to national debate over evolution and education. The trial tested whether a law introduced that year really could punish teachers over evolution lessons. It could and did: Scopes…

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When did nature burst into vivid color?

When did nature burst into vivid color?

Molly Herring writes: The natural world is awash with color, and many of these vibrant hues are meant to be seen. Apples blush red to coax animals to spread their seeds, lavender blooms are violet to lure in pollinating bees, and male peacocks trailed by flashy blue trains more successfully attract mates. However, the world is colorful only for some of us. These vivid signals can be perceived by animals that can see in color; to organisms that have limited…

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Vertebrates evolved intelligence independently multiple times

Vertebrates evolved intelligence independently multiple times

Yasemin Saplakoglu writes: Humans tend to put our own intelligence on a pedestal. Our brains can do math, employ logic, explore abstractions and think critically. But we can’t claim a monopoly on thought. Among a variety of nonhuman species known to display intelligent behavior, birds have been shown time and again to have advanced cognitive abilities. Ravens plan for the future, crows count and use tools, cockatoos open and pillage booby-trapped garbage cans, and chickadees keep track of tens of…

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Archaic humans might actually be the same species as modern humans, study suggests

Archaic humans might actually be the same species as modern humans, study suggests

Science Alert reports: Our species is defined by a long list of cultural and genetic traits that set us apart from our ancient counterparts. New research suggests at least some key distinctions date back earlier than previously estimated, hinting that modern and archaic humans – including our close, extinct relatives – have more in common than we ever thought. “Our results point to a scenario where Modern and Archaic should be regarded as populations of an otherwise common human species,…

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Scientists re-create the microbial dance that sparked complex life

Scientists re-create the microbial dance that sparked complex life

Molly Herring writes: Far from being solo operators, most single-celled microbes are in complex relationships. In the ocean, the soil and your gut, they might battle and eat each other, exchange DNA, compete for nutrients, or feed on one another’s by-products. Sometimes they get even more intimate: One cell might slip inside another and make itself comfortable. If the conditions are just right, it might stay and be welcomed, sparking a relationship that could last for generations — or billions…

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How primate eye tracking reveals new insights into the evolution of language

How primate eye tracking reveals new insights into the evolution of language

Mariya Surmacheva/Shutterstock By Vanessa Wilson, University of Hull The human environment is a very social one. Family, friends, colleagues, strangers – they all provide a continuous stream of information that we need to track and make sense of. Who is dating whom? Who is in a fight with whom? While our capacity for dealing with such a large social network is impressive, it’s not something especially unique to humans. Other primates do it too. We – humans and other primates…

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Hiker discovers first trace of entire prehistoric ecosystem in Italian Alps

Hiker discovers first trace of entire prehistoric ecosystem in Italian Alps

The Guardian reports: A hiker in the northern Italian Alps has stumbled across the first trace of what scientists believe to be an entire prehistoric ecosystem, including the well-preserved footprints of reptiles and amphibians, brought to light by the melting of snow and ice induced by the climate crisis. The discovery in the Valtellina Orobie mountain range in Lombardy dates back 280 million years to the Permian period, the age immediately prior to dinosaurs, scientists say. Claudia Steffensen, from Lovero,…

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