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Category: Evolution

Halos of clay can preserve billion-year-old microbes

Halos of clay can preserve billion-year-old microbes

Meredith Fore writes: Putting together the history of life on Earth has a major stumbling block: Prior to about 540 million years ago, most life was squishy and microbial, which meant it rarely fossilized. This major blind spot makes it difficult for researchers to study ancient life at a key point in Earth’s evolutionary history, and even more difficult to potentially find evidence of ancient microbial life on Mars. But a recent study of kaolinite, an aluminum-rich clay, gives researchers…

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Why are there so many humans?

Why are there so many humans?

By Karen L. Kramer, Sapiens, June 9, 2020 Something curious happened in human population history over the last 1 million years. First, our numbers fell to as low as 18,500, and our ancestors were more endangered than chimpanzees and gorillas. Then we bounced back to extraordinary levels, far surpassing the other great apes. Today the total population of gorillas, chimpanzees, bonobos, and orangutans is estimated to be only around 500,000, according to the World Wildlife Fund. Many species are critically…

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Are viruses alive? Perhaps we’re asking the wrong question

Are viruses alive? Perhaps we’re asking the wrong question

Axel_Kock/Shutterstock Hugh Harris, University College Cork Viruses are an inescapable part of life, especially in a global viral pandemic. Yet ask a roomful of scientists if viruses are alive and you’ll get a very mixed response. The truth is, we don’t fully understand viruses, and we’re still trying to understand life. Some properties of living things are absent from viruses, such as cellular structure, metabolism (the chemical reactions that take place in cells) and homeostasis (keeping a stable internal environment)….

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Out-of-sync ‘loners’ may secretly protect orderly swarms

Out-of-sync ‘loners’ may secretly protect orderly swarms

Jordana Cepelewicz writes: Dense clouds of starlings dip and soar, congregating in undulating curtains that darken the sky; hundreds of thousands of wildebeests thunder together across the plains of Africa in a coordinated, seemingly never-ending migratory loop; fireflies blink in unison; entire forests of bamboo blossom at once. Scientists have studied these mesmerizing feats of synchronization for decades, trying to tease apart the factors that enable such cooperation and complexity. Yet there are always individuals that don’t participate in the…

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How staying indoors affects your immune system

How staying indoors affects your immune system

Linda Geddes writes: For the past two months, a sizable chunk of the world’s population has been shuttered inside their homes, only stepping out for essential supplies. Although this may have reduced our chances of being exposed to coronavirus, it may have had a less obvious effect on our immune systems by leaving us more vulnerable to other infections. Humans evolved on a planet with a 24-hour cycle of light and dark, and our bodies are set up to work…

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The coronavirus is mutating, but that’s not necessarily good or bad

The coronavirus is mutating, but that’s not necessarily good or bad

Jeremy Draghi and C. Brandon Ogbunu write: In early March, the Chinese Academy of Sciences’ National Science Review published a peer-reviewed study titled “On the Origin and Continuing Evolution of SARS-CoV-2.” The authors argued that the various strains of SARS-CoV-2, the coronavirus that causes Covid-19, could be grouped into two clusters: An “L” type, which was predominant during the early weeks of the outbreak in Wuhan, and an “S” type, which could be distinguished from the L type by only…

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The coronavirus genome is like a shipping label that lets epidemiologists track where it’s been

The coronavirus genome is like a shipping label that lets epidemiologists track where it’s been

The steady rate of genetic changes lets researchers recreate how a virus has travelled. nextstrain.org, CC BY By Bert Ely, University of South Carolina and Taylor Carter, University of South Carolina Following the coronavirus’s spread through the population – and anticipating its next move – is an important part of the public health response to the new disease, especially since containment is our only defense so far. Just looking at an infected person doesn’t tell you where their version of…

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Why mammalian brains are geared toward kindness

Why mammalian brains are geared toward kindness

Patricia Churchland writes: Three myths about morality remain alluring: only humans act on moral emotions, moral precepts are divine in origin, and learning to behave morally goes against our thoroughly selfish nature. Converging data from many sciences, including ethology, anthropology, genetics, and neuroscience, have challenged all three of these myths. First, self-sacrifice, given the pressing needs of close kin or conspecifics to whom they are attached, has been documented in many mammalian species—wolves, marmosets, dolphins, and even rodents. Birds display…

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Billion-year-old algae and newer genes hint at origin of land plants

Billion-year-old algae and newer genes hint at origin of land plants

Dana Najjar writes: Around 500 million years ago — when the Earth was already a ripe 4 billion years old — the first green plants appeared on dry land. Precisely how this occurred is still one of the big mysteries of evolution. Before then, terrestrial land was home only to microbial life. The first green plants to find their way out of the water were not the soaring trees or even the little shrubs of our present world. They were…

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Humans (and most other animals) appear to be the descendants of tiny worms

Humans (and most other animals) appear to be the descendants of tiny worms

Reuters reports: A worm-like creature smaller than a grain of rice that burrowed on the sea floor in search of meals like dead organic matter about 555 million years ago may be the evolutionary forerunner of most animals living today – including people. Scientists on Monday announced the discovery in the Australian outback of fossils of this creature, named Ikaria wariootia, that represents one of the most important primordial animals ever found. It appears to be the earliest-known member of…

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Why did shamanism evolve in societies all around the globe?

Why did shamanism evolve in societies all around the globe?

Thomas T Hills writes: Shamanism is as varied as those who practise it. Its practitioners range from indigenous lineages who have passed down their craft over thousands of years to the modern ‘plastic shamans’, who represent no specific culture but have adapted shamanism to meet the demands of metropolitan markets. However, there is a common theme to shamanism wherever it is practised: the use of spiritual (or shamanic) trance to facilitate journeys to a non-ordinary reality. Here, in this non-ordinary…

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A new study shows an animal’s lifespan is written in the DNA. For humans, it’s 38 years

A new study shows an animal’s lifespan is written in the DNA. For humans, it’s 38 years

A genetic “clock” lets scientists estimate how long extinct creatures lived. Wooly mammoths could expect around 60 years. Australian Museum By Benjamin Mayne, CSIRO Humans have a “natural” lifespan of around 38 years, according to a new method we have developed for estimating the lifespans of different species by analysing their DNA. Extrapolating from genetic studies of species with known lifespans, we found that the extinct woolly mammoth probably lived around 60 years and bowhead whales can expect to enjoy…

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The anatomical ability to speak evolved millions of years before the rise of Homo sapiens

The anatomical ability to speak evolved millions of years before the rise of Homo sapiens

Baboons make sounds, but how does it relate to human speech? Creative Wrights/Shutterstock.com By Thomas R. Sawallis, University of Alabama and Louis-Jean Boë, Université Grenoble Alpes Sound doesn’t fossilize. Language doesn’t either. Even when writing systems have developed, they’ve represented full-fledged and functional languages. Rather than preserving the first baby steps toward language, they’re fully formed, made up of words, sentences and grammar carried from one person to another by speech sounds, like any of the perhaps 6,000 languages spoken…

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Our imagination has access to the pre-linguistic, ancestral mind

Our imagination has access to the pre-linguistic, ancestral mind

Stephen T Asma writes: Imagination is intrinsic to our inner lives. You could even say that it makes up a ‘second universe’ inside our heads. We invent animals and events that don’t exist, we rerun history with alternative outcomes, we envision social and moral utopias, we revel in fantasy art, and we meditate both on what we could have been and on what we might become. Animators such as Hayao Miyazaki, Walt Disney and the people at Pixar Studios are…

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Genes from bacteria helped plants move to land

Genes from bacteria helped plants move to land

Carl Zimmer writes: If you’ve ever noticed a slimy film of algae on a rock, chances are you didn’t pay it much attention. But some of these overlooked species hold clues to one of the greatest mysteries of evolution, scientists have found: how plants arrived on land. On Thursday, researchers published the genomes of two algae that are among the closest known living relatives of land plants. They already had some of the key genes that plants would need to…

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How conspiracy theories evolved from our drive for survival

How conspiracy theories evolved from our drive for survival

Jan-Willem van Prooijen writes: The great fire of Notre Dame on 15 April 2019 broke the hearts of culture lovers around the world. Parisians wept in public while the flames reduced large parts of this monumental cathedral to smouldering ashes. The French president Emmanuel Macron Tweeted a sentiment that not only French people felt: ‘Je suis triste ce soir de voir brûler cette part de nous’ (‘I feel sad tonight to see this part of us burn’). According to official…

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