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Category: Evolution

Catastrophe drives evolution, but life resides in the pauses

Catastrophe drives evolution, but life resides in the pauses

Renée A Duckworth writes: In certain places around the world – in the Badlands near Drumheller in Alberta, Canada, in the Geulhemmergroeve tunnels in the Netherlands, or in the Hell Creek formation in eastern Montana – you can touch a thin line of rock, and know you are touching the most famous mass extinction event on Earth. This Cretaceous-Paleogene (K-Pg) boundary layer is a seam of clay found all over the world, enriched with iridium – an element that appears…

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Brain-signal proteins evolved before animals did

Brain-signal proteins evolved before animals did

Viviane Callier writes: Our human brains can seem like a crowning achievement of evolution, but the roots of that achievement run deep: The modern brain arose from hundreds of millions of years of incremental advances in complexity. Evolutionary biologists have traced that progress back through the branch of the animal family tree that includes all creatures with central nervous systems, the bilaterians, but it is clear that fundamental elements of the nervous system existed much earlier. How much earlier has…

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Chimpanzees combine calls to form numerous vocal sequences

Chimpanzees combine calls to form numerous vocal sequences

Science Daily reports: Humans are the only species on earth known to use language. We do this by combining sounds to form words and words to form hierarchically structured sentences. The question, where this extraordinary capacity originates from, still remains to be answered. In order to retrace the evolutionary origins of human language, researchers often use a comparative approach — they compare the vocal production of other animals, in particular of primates, to those of humans. In contrast to humans,…

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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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