Browsed by
Category: Evolution

Fossil teeth reveal how brains developed in utero over millions of years of human evolution – new research

Fossil teeth reveal how brains developed in utero over millions of years of human evolution – new research

Any hominid fossil find with molar teeth can be plugged into a new equation that reveals its species’ prenatal growth rate. Gil Cohen-Magen/AFP via Getty Images By Tesla Monson, Western Washington University Fossilized bones help tell the story of what human beings and our predecessors were doing hundreds of thousands of years ago. But how can you learn about important parts of our ancestors’ life cycle – like pregnancy or gestation – that leave no obvious trace in the fossil…

Read More Read More

The Ordovician mass extinction: Our planet’s first brush with death

The Ordovician mass extinction: Our planet’s first brush with death

Cody Cottier writes: Some mass extinctions unfold like a sloppy murder, leaving clear fingerprints for the keen investigator to uncover. (Asteroids are no masters of subtlety.) The Late Ordovician mass extinction, the oldest of all and the second most lethal, isn’t one of them. Though there is a standard explanation for this granddaddy of death — involving an ancient ice age — the evidence is cryptic enough that experts are still submitting new theories for how 85 percent of all…

Read More Read More

The evolutionary importance of slime

The evolutionary importance of slime

Susanne Wedlich writes: The weather in Morro Bay, California is too good, the coastline too picturesque, and the wildlife seem to have waltzed straight out of a Disney film. Sea otters play in the waves with their young, herons bask on the beach, and seals stretch their plump bellies in the sun. And yet amid the tranquility of Morro Bay lurks a monster straight from H.P. Lovecraft’s playbook, as slimy as a creature from Sartre’s nightmares. It doesn’t get much…

Read More Read More

Ancient proteins offer new clues about origin of life on Earth

Ancient proteins offer new clues about origin of life on Earth

Science Daily: By simulating early Earth conditions in the lab, researchers have found that without specific amino acids, ancient proteins would not have known how to evolve into everything alive on the planet today — including plants, animals, and humans. The findings, which detail how amino acids shaped the genetic code of ancient microorganisms, shed light on the mystery of how life began on Earth. “You see the same amino acids in every organism, from humans to bacteria to archaea,…

Read More Read More

Why life is not a thing but a restless manner of being

Why life is not a thing but a restless manner of being

Tim Requarth writes: Mike Russell found his moment of inspiration on a warm spring evening in Glasgow in 1983, when his 11-year-old son broke a new toy. The toy in question was a chemical garden, a small plastic tank in which stalagmite-like tendrils grew out of seed crystals placed in a mineral solution. Although the tendrils appeared solid from the outside, when shattered they revealed their true nature: each one was actually a network of hollow tubes, like bundles of…

Read More Read More

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…

Read More Read More

Gene expression in neurons solves a brain evolution puzzle

Gene expression in neurons solves a brain evolution puzzle

Allison Whitten writes: The neocortex stands out as a stunning achievement of biological evolution. All mammals have this swath of tissue covering their brain, and the six layers of densely packed neurons within it handle the sophisticated computations and associations that produce cognitive prowess. Since no animals other than mammals have a neocortex, scientists have wondered how such a complex brain region evolved. The brains of reptiles seemed to offer a clue. Not only are reptiles the closest living relatives…

Read More Read More

We can still see these five traces of ancestor species in all human bodies today

We can still see these five traces of ancestor species in all human bodies today

Elia Pellegrini/Unsplash By Alice Clement, Flinders University Many of us are returning to work or school after spending time with relatives over the summer period. Sometimes we can be left wondering how on earth we are related to some of these people with whom we seemingly have nothing in common (especially with a particularly annoying relative). However, in evolutionary terms, we all share ancestors if we go far enough back in time. This means many features in our bodies stretch…

Read More Read More

Humans are still evolving thanks to microgenes

Humans are still evolving thanks to microgenes

The Scientist reports: Humans are still evolving new genes, according to a study published in Cell Reports on December 20. As our lineage evolved, at least 155 human genes sprung up from DNA regions previously thought of as “junk,” including two human-specific genes that emerged since humans branched off from chimpanzees around 4 to 6 million years ago, the researchers report. “I thought it was a great study,” says Alan Saghatelian, a biologist at the Salk Institute who was not…

Read More Read More

Inside ancient asteroids, gamma rays made building blocks of life

Inside ancient asteroids, gamma rays made building blocks of life

John Rennie and Allison Parshall write: In 2021, the Hayabusa2 space mission successfully delivered a morsel of the asteroid 162173 Ryugu to Earth — five grams of the oldest, most pristine matter left over from the solar system’s formation 4.5 billion years ago. Last spring, scientists revealed that the chemical composition of the asteroid includes 10 amino acids, the building blocks of proteins. The discovery added to the evidence that the primordial soup from which life on Earth arose may…

Read More Read More

An ancient partnership has helped both plants and fungi thrive over much of Earth

An ancient partnership has helped both plants and fungi thrive over much of Earth

Science reports: As a motley medley of mycologists climbed the basalt slopes of the Lanín volcano earlier this year, the green foliage at lower elevations gave way to autumnal golds and reds. Chile’s famed Araucaria—commonly called monkey puzzle trees—soon appeared, their spiny branches curving jauntily upward like so many cats’ tails. Beneath the majestic trees, the scientists were focused on something far less glamorous—indeed, mostly invisible: mycorrhizal fungi, tiny organisms that intertwine with roots of the Araucaria and nearly all…

Read More Read More

Strange, tentacled microbe may resemble ancestor of complex life

Strange, tentacled microbe may resemble ancestor of complex life

Science reports: By growing an unusual tentacled microbe in the lab, microbiologists may have taken a big step toward resolving the earliest branches on the tree of life and unraveling one of its great mysteries: how the complex cells that make up the human body—and all plants, animals, and many single-celled organisms—first came to be. Such microbes, called Asgard archaea, have previously been cultured—once—but the advance reported today in Nature marks the first time they’ve been grown in high enough…

Read More Read More

World’s oldest DNA discovered, revealing ancient Arctic forest full of mastodons

World’s oldest DNA discovered, revealing ancient Arctic forest full of mastodons

Scientific American reports: The oldest DNA ever recovered has revealed a remarkable two-million-year-old ecosystem in Greenland, including the presence of an unlikely explorer: the mastodon. The DNA, found locked in sediments in a region called Peary Land at the farthest northern reaches of Greenland, shows what life was like in a much warmer period in Earth’s history. The landscape, which is now a harsh polar desert, once hosted trees, caribou and mastodons. Some of the plants and animals that thrived…

Read More Read More

Fossil overturns more than a century of knowledge about the origin of modern birds

Fossil overturns more than a century of knowledge about the origin of modern birds

Science Daily reports: Fossilised fragments of a skeleton, hidden within a rock the size of a grapefruit, have helped upend one of the longest-standing assumptions about the origins of modern birds. Researchers from the University of Cambridge and the Natuurhistorisch Museum Maastricht found that one of the key skull features that characterises 99% of modern birds — a mobile beak — evolved before the mass extinction event that killed all large dinosaurs, 66 million years ago. This finding also suggests…

Read More Read More

Early humans may have cooked fish 780,000 years ago

Early humans may have cooked fish 780,000 years ago

Smithsonian magazine reports: Cooking with fire marked an important turning point in human evolution. But based on available evidence, determining exactly when early humans learned to cook is challenging. While researchers have discovered the remains of charred animals and root vegetables, that doesn’t necessarily mean people were grilling up steaks for dinner; they may have simply tossed a dead animal into the fire for disposal. Now, researchers in Israel say they’ve come up with a clever solution to this problem—and,…

Read More Read More

Parasite gives wolves what it takes to be pack leaders

Parasite gives wolves what it takes to be pack leaders

Nature reports: Wolves infected with a common parasite are more likely than uninfected animals to lead a pack, according to an analysis of more than 200 North American wolves1. Infected animals are also more likely to leave their home packs and strike out on their own. The parasite, Toxoplasma gondii, makes its hosts bold — a mechanism that increases its survival. To reproduce sexually, T. gondii must reach the body of a cat, usually when its host is eaten by…

Read More Read More