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Category: Evolution

On the origin of feces: How animal poo drove Earth’s greatest evolutionary event

On the origin of feces: How animal poo drove Earth’s greatest evolutionary event

Kimmig & Bicknell / Trends in Ecology & Evolution, CC BY By Russell Dean Christopher Bicknell, Flinders University and Julien Kimmig As all children learn, everyone poos. But when did this begin? And what evolutionary and environmental changes accompanied the dawn of dung? Going further, is the evolution of excrement the reason we exist? Our new research suggests the evolution of fecal matter helped fuel one of the most important events in the history of life on Earth: the Cambrian…

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New study points to two origins of life on Earth

New study points to two origins of life on Earth

Smithsonian magazine reports: Among biologists, few questions have been debated as fiercely as the origin of life. How did self-sustaining organisms, capable of transforming molecules to capture energy, arise on the primitive Earth? Before any cells existed, scientists suspect chemical reactions occurred around deep-sea hydrothermal vents, where heat and high pressures led to spontaneous chemistry that was sped up, or catalyzed, by metals in Earth’s crust. One possibility for the origin of life is that, over time, these relatively simple…

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Origin of human eyes traced to 560-million-year-old one-eyed marine ‘cyclops’

Origin of human eyes traced to 560-million-year-old one-eyed marine ‘cyclops’

ZME Science reports: Deep inside the human brain, a small gland in the middle of the forehead helps keep time. As darkness arrives, the pineal gland helps set the body’s nightly rhythm. But some creatures use the pineal gland as a sort of “third eye”, helping them detect light and shadow, though the organ doesn’t form pictures. Our human lineage lost this ancestral ability millions of years ago. But a new evolutionary hypothesis suggests that this unassuming organ is the…

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The extinction of dinosaurs, along with most other species, may have happened in less than two hours

The extinction of dinosaurs, along with most other species, may have happened in less than two hours

Popular Science reports: The reign of the dinosaurs undisputedly came to a dramatic conclusion 66 million years ago, after the six-mile-wide Chicxulub asteroid slammed into what is now Mexico’s Yucatán Peninsula. However, the exact timeline of their extinction remains a matter of debate. Did most of the Earth’s species die a slow death of starvation after a dust-choked atmosphere blocked sunlight and ushered in a prolonged winter? Or did they quickly incinerate from globe-spanning wildfires sparked by falling, superheated space…

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Human evolution was messy and gradual, not an abrupt revolution, archaeologist argues

Human evolution was messy and gradual, not an abrupt revolution, archaeologist argues

Krystal Kasal writes: It is generally accepted by archaeologists that modern humans originated in Africa and dispersed worldwide, while other hominins went extinct. Yet how and when Homo sapiens dispersed out of Africa, and whether it was an abrupt event, is still debated. Even more uncertain is how and when humans went from being “archaic” to “modern.” In a recent study, published in Quaternary Science Reviews, archaeologist Huw S. Groucutt argues that the ideas of modernity and a “Human Revolution”…

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Ancient DNA reveals how natural selection shaped West Eurasians over 10,000 years

Ancient DNA reveals how natural selection shaped West Eurasians over 10,000 years

PsyPost reports: By analyzing the genetic material of thousands of ancient humans, researchers have mapped how natural selection influenced hundreds of physical and behavioral traits across West Eurasia over the past 10,000 years. The findings reveal that evolution continuously pushed specific genetic variations to become more or less common, affecting everything from blood type to disease risk. The study was published in Nature. Evolution is driven by multiple forces, but one of the most recognizable is directional selection. This happens…

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The tightrope of cooperation and competition

The tightrope of cooperation and competition

Jonathan R Goodman writes: Reading classic works in evolutionary biology is unlikely to make you optimistic about human nature. From Charles Darwin’s The Descent of Man (1871) onwards, there is a fundamental understanding among biologists that organisms, especially humans, evolved to maximise self-interest. We act to promote our own success or that of our family. Niceness, by contrast, is just a mirage, and morality more broadly is just an illusion. Sociobiology – the infamous movement of the second half of…

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How ecotypes harbor the genetic memory of a species’ past

How ecotypes harbor the genetic memory of a species’ past

Marlowe Starling writes: When she was a graduate student in the 1970s, the evolutionary biologist Kerstin Johannesson regularly walked the shores of a Swedish archipelago, scanning the ground for pebbles that moved: marine snails. Her adviser, a taxonomist, had tasked her with describing the species present there by documenting their traits. She noticed that snails with thicker shells stayed on the shore, while those with thinner shells seemed to prefer wave-battered rocks, and in between the two habitats were snails…

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A vast meshwork of soil-bound fungi governs life aboveground

A vast meshwork of soil-bound fungi governs life aboveground

Max G. Levy writes: One Tuesday in June 2025, a white Chevy Suburban set off down the northernmost highway in North America. The sun of Alaska’s polar summer hadn’t set in 40 days, and it wouldn’t set again for another 35. But for Michael Van Nuland, the biologist in the driver’s seat, time was already running out. The SUV, packed with four days of fieldwork essentials — rubber boots for mucking in marshes, GPS for centimeter-level precision, a steel tube…

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If wings came before flight, what were they for?

If wings came before flight, what were they for?

Lily Burton writes: Flight may be one of evolution’s most iconic innovations, but zoologist Piotr Jablonski is convinced that early wings were first meant to be seen, not to fly. The idea came to Jablonski after studying bird behavior in the American West. He noticed some birds would fling out their wings or fan out their tail feathers to lure insects into the open. Then the birds would catch and eat the bugs. If early winged dinosaurs were the ancestors…

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Neuroscientists are studying octopuses for insights into how intelligence evolved

Neuroscientists are studying octopuses for insights into how intelligence evolved

Nature reports: Three hearts; blue blood; no skeleton; arms like tongues. These are just some of the alien features of octopuses, squid and cuttlefish — members of the cephalopod family. The outlandish list continues. Cephalopod skin can taste chemicals, sense light and change colour and texture rapidly. In many species, the sucker-covered arms can even regenerate. These invertebrates have evolved independently from the vertebrate lineage for more than 600 million years. Their last common ancestor was probably a worm-like creature…

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Evolution before life

Evolution before life

Dyna Rochmyaningsih writes: A story about the origins of life in the cosmos starts at Earth’s equator, where Dian Fiantis, a professor of soil science at Andalas University in Indonesia, investigated how seemingly dead environments come back to life. In 2018, she traveled to Mt. Anak Krakatoa (which emerged after the famous Krakatoa’s eruption) to collect the volcanic ash it ejected two months before. In her lab, she found out that volcanic glass (SiO2), the dominant chemical found in the…

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How farming changed us: Ancient DNA reveals natural selection sped up in recent human evolution

How farming changed us: Ancient DNA reveals natural selection sped up in recent human evolution

Harvard Medical School: A massive study of ancient DNA from nearly 16,000 people across more than 10,000 years in West Eurasia reveals that natural selection has shaped modern human genomes far more than previously thought. Before now, studies of ancient human DNA had identified only about 21 instances of directional selection—the type of natural selection that occurs when one version of a gene that confers an extreme form of a trait, such as lactose tolerance after infancy, proves advantageous enough…

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‘First contact’ that may have led to complex life on Earth finally witnessed by scientists

‘First contact’ that may have led to complex life on Earth finally witnessed by scientists

Microscopic image showing newly discovered Asgard archaeon (Nerearchaeum marumarumayae) derived from microbial mats that offers clues to the formation of complex life. Debnath Ghosal By Brendan Paul Burns, UNSW Sydney and Kymberley Oakley, Indigenous Knowledge On the shores of the west coast of Australia lies a window to our past: the stromatolites and microbial mats of Gathaagudu (Shark Bay). To the untrained eye they look like a collection of rocks and slime – but they are in fact teeming with…

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We are all collections of errors

We are all collections of errors

Jerome Groopman writes: As I am writing this, my DNA is changing. And, as you read this, so is yours. People tend to assume that the genes we inherit from our parents are a fixed blueprint for our growth and development, immutable throughout our lives, and that the DNA in each cell of our body is the same as in every other cell. In fact, changes in our DNA, known as mutations, occur from the time we are in the…

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Disorder drives one of nature’s most complex molecular machines

Disorder drives one of nature’s most complex molecular machines

Yasemin Saplakoglu writes: At the dawn of complex life, evolution created a container for DNA, its most treasured item. A few billion years later, 20th-century microscopists looked at this container — the nucleus — up close and saw that it was covered in tiny openings. At the time, they didn’t know what to make of these structures, but as microscopy improved, something grand came into focus: what we now call “nuclear pore complexes,” some of the largest and most marvelous…

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