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Category: Evolution

How did life arise?

How did life arise?

The New York Times reports: Life on planet Earth is a riot of diversity: ants and elephants, frogs and blue whales, tulips and redwoods, even a branch of the great apes known as humans. Uniting it all is biochemistry, in particular the shared biochemistry of genetic inheritance — DNA and RNA, the universal instruction kits of life. Tracing these biochemical threads back through time has convinced many scientists that all life descends from a so-called Last Universal Common Ancestor, or…

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A human gene lurks in a virus that causes skin infections

A human gene lurks in a virus that causes skin infections

The New York Times reports: Scientists have discovered a virus that is a tiny bit human, carrying a gene it stole from our ancestors about 100,000 years ago. And this virus may be using our own gene to infect us. Previous studies have demonstrated that viruses can pick up genes from their hosts. But the new discovery, reported Thursday in the journal Science, may be the first known instance of a virus with a human gene acquired in recent evolutionary…

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In an $80 motel room, a discovery sheds light on the origins of life

In an $80 motel room, a discovery sheds light on the origins of life

The New York Times reports: On a spring day last year, Andrew Willoughby drove three and a half hours to a cheap motel in Nags Head, N.C. From the parking lot, he texted a stranger he had met online. Julia Van Etten appeared, ushering him past a “Do Not Disturb” sign into one of the motel’s $80 rooms, which she had secretly turned into a makeshift lab. Jugs of brackish water lined the walls. Buckets overflowed with hunks of marsh…

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How virus-like ‘jumping genes’ became our partners in evolution

How virus-like ‘jumping genes’ became our partners in evolution

Jake Buehler writes: You might imagine that the DNA in your cells has a simple history. Even though it’s been recombined in every generation through sex and gained the occasional mutation, on the whole the genome has been stable and has been passed down reliably from your ancestors. But that’s not the entire story. Nearly half of your genome is a wild drama: mobile, repetitive, disruptive, even viral. This half is the result of genetic material that can clip itself…

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A fossilized feather from the age of dinosaurs may explain why only some birds survived

A fossilized feather from the age of dinosaurs may explain why only some birds survived

NPR reports: Paleontology can be quite physical. In 2016, David DeMar was doing field work in the rocky badlands of Montana in what’s known as the Hell Creek Formation. “We all get down on our hands and knees,” he recalls. “And I start crawling up the hill and I noticed this little dark, round object on the ground. It was kind of odd.” DeMar, a lab manager at the Burke Museum in Seattle, picked up the cherry-sized fossil. “I start…

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Ancient ‘living fossils’ may reveal how complex life began

Ancient ‘living fossils’ may reveal how complex life began

Science Daily reports: At first glance, stromatolites and their close relatives, microbial mats, can look like little more than dark, ancient rocks. In reality, they are densely packed, layered communities built by microbes. Billions of years ago, before animals and plants existed, stromatolites helped release some of the earliest oxygen into Earth’s atmosphere. Now, a study published in Current Biology suggests these unusual formations may also preserve clues to another major event in Earth’s history: the emergence of complex life….

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The brain isn’t hardwired to read – here’s how we pull it off and why some are better at it than others

The brain isn’t hardwired to read – here’s how we pull it off and why some are better at it than others

By Mikael Roll, Lund University For an experienced reader, recognising the words on this page feels effortless. Yet, evolutionarily speaking, your brain shouldn’t be able to read. Reading has existed for too short a time to have shaped a dedicated centre in the brain. Therefore, the brain has to learn to read using systems that evolved for other purposes. But it has long been unclear exactly which systems it recruits to do so and how. This is important, as differences…

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Why it might be time to rethink the human family tree

Why it might be time to rethink the human family tree

Ian Towle, CC BY By Ian Towle, Monash University Humanity’s family tree is long and tangled. Scientists sort our ancient relatives into three familiar groups: Homo, Australopithecus and Paranthropus. Each of these is a “genus”, the rank just above a species. (In Homo sapiens, Homo is the genus and sapiens is the species.) These names dominate how we talk about human origins. But new fossils, advances in genetic analysis, and more rigorous methods for figuring out who’s related to whom…

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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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