Category Archives: Evolution

Tracing the tangled tracks of humankind's evolutionary journey

The path from ape to modern human is not a linear one. Hannah Devlin looks at what we know – and what might be next for our species

Let’s go back to the beginning. When did we and our ape cousins part ways?
Scientists are still working on an exact date – or even a date to within a million years. Like many of the big questions in human evolution, the answer itself has evolved over the past few decades as new discoveries, techniques and technology have provided fresh insights.

Genetics has proved one of the most powerful tools for time-stamping the split with our closest living relative, the chimpanzee. When our complete genomes were compared in 2005, the two species were found to share 98% of their DNA. The differences hold important clues to how long our lineages have been diverging. By estimating the rate at which new genetic mutations are acquired over generations, scientists can use the genetic differences as a “molecular clock” to give a rough idea of when the split occurred. Most calculations suggest it was between four to eight million years ago.

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Source: gad

'He's one of us': modern neighbours welcome Cheddar Man

DNA tests suggesting man who lived 10,000 years ago had dark skin and blue eyes cause a stir

Rachel Andrews, who was tending the bar at the Black Dog Saloon, a wild west-themed cider pub at the foot of Cheddar Gorge, was not going to have a word said against the village’s most famous former resident.

“We’re very proud of Cheddar Man,” she said. “There’s a really good, strong community spirit around here. We all look after each other and he’s definitely one of us.”

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Source: gad

First modern Britons had 'dark to black' skin, Cheddar Man DNA analysis reveals

The genome of Cheddar Man, who lived 10,000 years ago, suggests that he had blue eyes, dark skin and dark curly hair

The first modern Britons, who lived about 10,000 years ago, had “dark to black” skin, a groundbreaking DNA analysis of Britain’s oldest complete skeleton has revealed.

The fossil, known as Cheddar Man, was unearthed more than a century ago in Gough’s Cave in Somerset. Intense speculation has built up around Cheddar Man’s origins and appearance because he lived shortly after the first settlers crossed from continental Europe to Britain at the end of the last ice age. People of white British ancestry alive today are descendants of this population.

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Source: gad

Cultural taboos around food are powerful – could vegans change ours?

As campaigns such as Veganuary become more popular could the way westerners categorise what’s edible start to shift?

Yesterday marked the end of “Veganuary”, the campaign to encourage people to try a vegan lifestyle for a month. Year on year the trend has grown. Might those one-month vegans change the habits of the rest of us – by changing what an animal is?

Vegans shun all animal-derived products – meat, fish and leather obviously, but also eggs, dairy products, honey and wool. Beers refined using isinglass (derived from fish guts) are out, as would the new UK £5 and £10 notes, if they could be. The term itself was coined back in 1944, bringing together the start and end of the word VEGetariAN, as the next step on.

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Source: gad

Oldest known human fossil outside Africa discovered in Israel

Human ancestors left Africa far earlier than previously thought, discovery of prehistoric jawbone and tools suggest

A prehistoric jawbone discovered in a cave in Israel has prompted scientists to rethink theories of how the earliest human pioneers came to populate the planet, suggesting that our ancestors left Africa far earlier than previously thought.

The fossil, dated to nearly 200,000 years ago, is almost twice as old as any previous Homo sapiens remains discovered outside Africa, where our species is thought to have originated.

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Source: gad

How do you sex a fossil? | Elsa Panciroli

How can we tell if an extinct animal is male or female? And how did dinosaurs mate?

“It was a slit, like this,” Vinther held his cupped hands side by side and opened and closed them, like a puppet’s mouth. “That’s it. That’s what a dinosaur cloaca looked like.”

For those who don’t habituate the often explicit world of natural scientists, let me explain. A cloaca is the opening through which most vertebrate animals excrete their waste and have sex. It is an all-purpose exit and entry-point. Jakob Vinther from the University of Bristol, and his colleagues, are currently describing the only known dinosaur cloaca. It belongs to a spectacular Psittacosaurus specimen that preserves details of skin texture and even colouration. Their upcoming research will be the first ever scientific description of actual dino-privates.

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Source: gad

Strangest things: fossils reveal how fungus shaped life on Earth

Fossil fungi from over 400m years ago have altered our understanding of early life on land and climate change over deep time

Much of the weirdness depicted in the TV show Stranger Things is distinctly fungal. The massive organic underground network, the floating spores, and even the rotting pumpkin fields all capture the “otherness” of fungi: neither plants nor animals, often bizarre-looking, and associated with decay. As weird as they may seem to us, fungi are integral to the story of the evolution of our landscapes and climate.

Molecular studies show us that animals and fungi share a more recent common ancestor than either group does with plants, and that these groups had all diverged over a billion years ago. A sparse fossil record for fungi is not entirely surprising, given the low preservation potential of soft, microscopic threads, but we still have tantalising glimpses of their history. Recent work on the Rhynie Chert, a deposit formed in hydrothermal wetlands 407m years ago, preserving an early land ecosystem in exquisite detail, has helped to reveal the hidden history of fungi. All modern groups of fungi are abundant in Rhynie chert samples apart from the basidiomycota, the group which includes those most familiar of fungi: mushrooms. New findings have been published in a special volume of the Philosophical Transactions of the Royal Society B.

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Source: gad