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Category: Evolution

Fossilized molecules reveal a lost world of ancient life

Fossilized molecules reveal a lost world of ancient life

Yasemin Saplakoglu writes: A tree has something in common with the weeds and mushrooms growing around its roots, the squirrels scurrying up its trunk, the birds perched on its branches, and the photographer taking pictures of the scene. They all have genomes and cellular machinery neatly packed into membrane-bound compartments, an organizational system that places them in an immensely successful group of life forms called eukaryotes. The early history of eukaryotes has long fascinated scientists who yearn to understand when…

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Where did all those structures inside complex cells come from?

Where did all those structures inside complex cells come from?

Viviane Callier writes: More than 1.5 billion years ago, a momentous thing happened: Two small, primitive cells became one. Perhaps more than any event — barring the origin of life itself — this merger radically changed the course of evolution on our planet. One cell ended up inside the other and evolved into a structure that schoolkids learn to refer to as the “powerhouse of the cell”: the mitochondrion. This new structure provided a tremendous energetic advantage to its host…

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Bizarre blob-like animal may hint at origins of neurons

Bizarre blob-like animal may hint at origins of neurons

Live Science reports: A sea animal so simple that it looks like a blobby pancake may hold the secret to the origin of neurons. Placozoans are one of the five major branches of animals, along with bilaterians (which include everything from worms to humans), cnidarians (corals and medusas), sponges and ctenophores (comb jellies). They’re the most basic of the bunch, consisting of millimeter-long blobs of cells without organs or body parts. They move through the water using cilia — tiny…

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It’s reassuring to think humans are evolution’s ultimate destination – but research shows we may be an accident

It’s reassuring to think humans are evolution’s ultimate destination – but research shows we may be an accident

The Cambrian explosion, about 530 million years ago, was when most of the major groups of animals first appear in the fossil record. canbedone/Shutterstock By Matthew Wills, University of Bath and Marcello Ruta, University of Lincoln Depending upon how you do the counting, there are around 9 million species on Earth, from the simplest single-celled organisms to humans. It’s reassuring to imagine that complex bodies and brains like ours are the inevitable consequence of evolution, as if evolution had a…

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Elephants never forget war

Elephants never forget war

Charles Digges writes: If, as the saying goes, elephants never forget, then the elephants in the wildlife haven of Gorongosa National Park probably remember Mozambique’s civil war better than some humans do. So indelible are the memories of the country’s 15-year-long civil war, which raged from 1977 to 1992, that they are written in the elephants’ genes. As a result of the massive slaughter by the warring soldiers, who traded ivory to finance weapons for their protracted struggle, more and…

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Earth’s story is not about dynasties but communities

Earth’s story is not about dynasties but communities

Riley Black writes: The worst day in the entire history of life on Earth happened in the northern springtime. On that day, the last of the Age of Dinosaurs, a roughly seven-mile-wide chunk of rock that had been hurtling towards our orbit for millions of years slammed into Earth’s midsection and immediately brought the Cretaceous to a close. The consequences were so dire that survival in the hours immediately following impact was merely a matter of luck. Of course, life…

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Another path to intelligence

Another path to intelligence

James Bridle writes: It turns out there are many ways of “doing” intelligence, and this is evident even in the apes and monkeys who perch close to us on the evolutionary tree. This awareness takes on a whole new character when we think about those non-human intelligences which are very different to us. Because there are other highly evolved, intelligent, and boisterous creatures on this planet that are so distant and so different from us that researchers consider them to…

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Selfish, virus-like DNA can carry genes between species

Selfish, virus-like DNA can carry genes between species

Saugat Bolakhe writes: Biologists have understood the broad contours of the rules of inheritance for more than a century: that genes are passed down from parent to child within species. But in more recent years, they have also become aware of genes that go rogue and hop laterally between species — be they frog genes in Madagascar that originally came from snakes, or antifreeze genes found in cold-water fish like herring that transferred to smelts. The mechanism facilitating this gene…

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Why did Darwin’s 20th-century followers get evolution so wrong?

Why did Darwin’s 20th-century followers get evolution so wrong?

James A Shapiro writes: Since 1859, when Charles Darwin’s On the Origin of Species was first published, the theory of natural selection has dominated our conceptions of evolution. As Darwin understood it, natural selection is a slow and gradual process that takes place across multiple generations through successive random hereditary variations. In the short term, a small variation might confer a slight advantage to an organism and its offspring, such as a longer beak or better camouflage, allowing it to…

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How could ancient viruses embedded in our DNA fight cancer?

How could ancient viruses embedded in our DNA fight cancer?

Discover magazine reports: Millions of years ago, our ancestors, like us today, had to contend with viruses. No doubt the infections were unpleasant for them at the time, but their suffering wasn’t for naught — some of those viruses left traces in our DNA. And, according to scientists at the Francis Crick Institute, these remnants may aid the body’s immune response to cancer today. While studying lung cancer in mice and in human tumor samples, the team found that immunotherapy…

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How did birds master flight?

How did birds master flight?

Carl Zimmer writes: In 1993, “Jurassic Park” helped inspire 9-year-old Stephen Brusatte to become a paleontologist. So Dr. Brusatte was thrilled to advise the producers of last year’s “Jurassic World: Dominion” on what scientists had learned about dinosaurs since he was a child. He was especially happy to see one of the most important discoveries make it to the screen: dinosaurs that sported feathers. But judging from the emails he has been receiving, some moviegoers did not share his excitement….

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Time is not an illusion

Time is not an illusion

Sara Walker and Lee Cronin write: A timeless universe is hard to imagine, but not because time is a technically complex or philosophically elusive concept. There is a more structural reason: imagining timelessness requires time to pass. Even when you try to imagine its absence, you sense it moving as your thoughts shift, your heart pumps blood to your brain, and images, sounds and smells move around you. The thing that is time never seems to stop. You may even…

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A chance event one million years ago changed human brains forever

A chance event one million years ago changed human brains forever

Science Alert reports: Like treasured recipes passed down from generation to generation, there are just some regions of DNA that evolution doesn’t dare tweak. Mammals far and wide share a variety of such encoded sequences, for example, which have remained untouched for millions of years. Humans are a strange exception to this club. For some reason, recipes long preserved by our ancient ancestors were suddenly ‘spiced up’ within a short evolutionary period of time. Because we’re the only species in…

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The sleeping beauties of biological evolution

The sleeping beauties of biological evolution

Andreas Wagner writes: What are the most successful organisms on the planet? Some people might think of apex predators like lions and great white sharks. For others, insects or bacteria might come to mind. But few would mention a family of plants that we see around us every day: grasses. Grasses meet at least two criteria for spectacular success. The first is abundance. Grasses cover the North American prairies, the African savannahs and the Eurasian steppes, which span 5,000 miles…

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Imagination makes us human – this unique ability to envision what doesn’t exist has a long evolutionary history

Imagination makes us human – this unique ability to envision what doesn’t exist has a long evolutionary history

Your brain can imagine things that haven’t happened or that don’t even exist. agsandrew/iStock via Getty Images Plus By Andrey Vyshedskiy, Boston University You can easily picture yourself riding a bicycle across the sky even though that’s not something that can actually happen. You can envision yourself doing something you’ve never done before – like water skiing – and maybe even imagine a better way to do it than anyone else. Imagination involves creating a mental image of something that…

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Primitive Asgard cells show life on the brink of complexity

Primitive Asgard cells show life on the brink of complexity

Joshua Sokol writes: An oak tree. The symbiotic fungus intertwined with its roots. A cardinal chirping from one of its branches. Our best clue yet to their shared ancestor might have arrived in electron microscope images that were unveiled in December. “Look!” said the microbiologist Christa Schleper, beaming as she held a printed, high-resolution image in front of her webcam at the University of Vienna. “Isn’t it beautiful?” The cells in the micrograph were 500 nanometer-wide orbs surrounded by a…

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