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Category: Evolution

Wild animals are evolving faster than anybody thought

Wild animals are evolving faster than anybody thought

Shutterstock By Timothée Bonnet, Australian National University How fast is evolution? In adaptive evolution, natural selection causes genetic changes in traits that favour the survival and reproduction of individual organisms. Although Charles Darwin thought the process occurred over geological timescales, we have seen examples of dramatic adaptive evolution over only a handful of generations. The peppered moth changed colour in response to air pollution, poaching has driven some elephants to lose their tusks and fish have evolved resistance to toxic…

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Origin of life theory involving RNA–protein hybrid gets new support

Origin of life theory involving RNA–protein hybrid gets new support

Nature reports: Chemists say they have solved a crucial problem in a theory of life’s beginnings, by demonstrating that RNA molecules can link short chains of amino acids together. The findings, published on 11 May in Nature, support a variation on the ‘RNA world’ hypothesis, which proposes that before the evolution of DNA and the proteins it encodes, the first organisms were based on strands of RNA, a molecule that can both store genetic information — as sequences of the…

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Why the father of neuroscience, toward the end of his career, preferred to study ants

Why the father of neuroscience, toward the end of his career, preferred to study ants

Benjamin Ehrlich writes: In 1914, when World War I broke out, Santiago Ramón y Cajal, the most influential neuroscientist in the world—the man who discovered brain cells, later termed neurons— published only one article, by far his lowest output ever. “The horrendous European war of 1914 was for my scientific activity a very rude blow,” Cajal recalled. “It altered my health, already somewhat disturbed, and it cooled, for the first time, my enthusiasm for investigation.” Cajal’s tertulia, or café social…

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The awake ape: Why people sleep less than their primate relatives

The awake ape: Why people sleep less than their primate relatives

Elizabeth Preston writes: On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t gotten any more hours of sleep than a typical Western city-dweller who stayed up doom-scrolling on their smartphone. Research has shown that people in non-industrial societies — the closest thing to the kind of setting our species evolved in — average less than…

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Ancient genes for symbiosis hint at mitochondria’s origins

Ancient genes for symbiosis hint at mitochondria’s origins

Veronique Greenwood writes: Once, long ago, the only players in the grand drama of life, predation and death were invisibly small and simple cells. Archaea and bacteria jigged and whirled through seas and ponds, assembled themselves into fortresses a few microns wide, and devoured films of organic matter. Then some of them began to change, and eventually the first eukaryote — the first organism to keep its genes locked away in a nucleus, to line its interior with ramifying compartments,…

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How trance states forged human society through transcendence

How trance states forged human society through transcendence

Mark Vernon writes: A change has come over the public discussion of religion in recent years. In the decade of the New Atheists, religion was the root of all evil. Nowadays, however, it tends to be thought of as a good, even necessary, part of society. In his recent book Dominion: The Making of the Western Mind (2019), the agnostic historian Tom Holland argues that Christianity underpins our civilisation; and the atheist philosopher John Gray has repeatedly stressed that atheism…

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Before neurons evolved, mechanics may have governed animal behavior

Before neurons evolved, mechanics may have governed animal behavior

Jordana Cepelewicz writes: The biophysicist Manu Prakash vividly remembers the moment, late one night in a colleague’s laboratory a dozen years ago, when he peered into a microscope and met his new obsession. The animal beneath the lenses wasn’t much to look at, resembling an amoeba more than anything else: a flattened multicellular blob, only 20 microns thick and a few millimeters across, with neither head nor tail. It moved on thousands of cilia that blanketed its underside to form…

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Even worms feel pain

Even worms feel pain

David P. Barash writes: Who feels more pain, a person or a cat? A cat or a cockroach? It’s widely assumed animal intelligence and the capacity to feel pain are positively correlated, with brainier animals more likely to feel pain, and vice versa. But what if our intuition is wrong and the opposite is true? Perhaps animals that are less intelligent feel not only as much pain but even more. Thinking about pain is psychologically challenging. It can be, well,…

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Laws of nature are impossible to break, and nearly as difficult to define

Laws of nature are impossible to break, and nearly as difficult to define

Marc Lange writes: In the original Star Trek, with the Starship Enterprise hurtling rapidly downward into the outer atmosphere of a star, Captain James T Kirk orders Lt Commander Montgomery Scott to restart the engines immediately and get the ship to safety. Scotty replies that he can’t do it. It’s not that he refuses to obey the Captain’s order or that he doesn’t happen to know how to restart the engines so quickly. It’s that he knows that doing so…

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Peptides on stardust may have provided a shortcut to life

Peptides on stardust may have provided a shortcut to life

Yasemin Saplakoglu writes: Billions of years ago, some unknown location on the sterile, primordial Earth became a cauldron of complex organic molecules from which the first cells emerged. Origin-of-life researchers have proposed countless imaginative ideas about how that occurred and where the necessary raw ingredients came from. Some of the most difficult to account for are proteins, the critical backbones of cellular chemistry, because in nature today they are made exclusively by living cells. How did the first protein form…

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A billion years before sex, ancient cells were equipped for it

A billion years before sex, ancient cells were equipped for it

Jake Buehler writes: Most complex organisms engage in a strange bit of genomic math at some point in their lives: To multiply, they subtract and then add. That is, to reproduce through the process of meiosis they create specialized sex cells, or gametes, with half the usual number of chromosomes; they then merge pairs of those gametes to create new individuals with a full, unique genome. Sexual reproduction is nearly ubiquitous among eukaryotes — organisms from kelp to koalas that…

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An ancient link between heart and head — as seen in the blobby, headless sea squirt

An ancient link between heart and head — as seen in the blobby, headless sea squirt

Nature reports: The head is stately, calm, and wise, And bears a princely part; And down below in secret lies The warm, impulsive heart. — John Godfrey Saxe, 1898 For centuries, writers have mused on the heart as the core of humanity’s passion, its morals, its valour. The head, by contrast, was the seat of cold, hard rationality. In 1898, US poet John Godfrey Saxe wrote of such differences, but concluded his verses arguing that the heart and head are…

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New database reveals impact humans are having on evolution

New database reveals impact humans are having on evolution

Wired reports: Charles Darwin thought of evolution as an incremental process, like the patient creep of glaciers or the march of continental plates. “We see nothing of these slow changes in progress until the hand of time has marked the long lapse of ages,” he wrote in On the Origin of Species, his famous 1859 treatise on natural selection. But by the 1970s, scientists were finding evidence that Darwin might be wrong—at least about the timescale. Peppered moths living in…

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Secrets of early animal evolution revealed by chromosome ‘tectonics’

Secrets of early animal evolution revealed by chromosome ‘tectonics’

Viviane Callier writes: Chromosomes, the bundles of DNA that star in the mitotic ballet of cell division, play a leading role in complex life. But the question of how chromosomes came to exist and evolve has long been discouragingly hard to answer. This is due partly to the lack of chromosome-level genomic information and partly to the suspicion that eons of evolutionary change have washed away any clues about that ancient history. Now, in a paper appearing today in Science…

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Scientists find hints of a hidden mass extinction 30 million years ago

Scientists find hints of a hidden mass extinction 30 million years ago

Inside Science reports: Nearly two-thirds of mammal species in Africa and the Arabian Peninsula may have died off about 30 million years ago, a mass extinction that escaped detection for decades until now, a new study finds. During a time span known as the Eocene-Oligocene transition between 40 million and 34 million years ago, Earth’s climate shifted dramatically, with the planet growing cooler, ice sheets expanding and sea levels dropping worldwide. During the Eocene, Antarctica was covered by lush forests,…

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Humans have evolved to stay active even in old age, new hypothesis claims

Humans have evolved to stay active even in old age, new hypothesis claims

Science Alert reports: In the modern western world, people tend to reduce their levels of physical activity as they get older. But with this inactivity comes a raft of adverse health effects, so why didn’t evolution engineer us so that people could maintain a decent quality of life as they inevitably slow down? In a newly published paper, researchers argue it is because we aren’t meant to reduce our physical activity as we age at all. Enter the ‘active grandparent…

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