Category Archives: Genetics

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

How afraid of human cloning should we be? | Philip Ball

The creation of two monkeys brings the science of human cloning closer to reality. But that doesn’t mean it will happen

The cloning of macaque monkeys in China makes human reproductive cloning more conceivable. At the same time, it confirms how difficult it would be to clone a random adult – Adolf Hitler, say – from a piece of their tissue. And it changes nothing in the debate about whether such human cloning should ever happen.

Since the cloning of Dolly the sheep by scientists in Scotland in 1996, several other mammals have been cloned, including dogs, cats and pigs. But the same methods didn’t work so well for primates – like monkeys, and us. That’s why this latest step is significant. It shows that, with a bit of modification, the technique used for Dolly can create cloned, apparently healthy baby monkeys. The pair made this way by scientists at the Institute of Neuroscience in Shanghai have been christened Hua Hua and Zhong Zhong.

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Source: gad

Think twice about buying ‘squashed-faced’ breeds, vets urge dog-lovers

British Veterinary Association launches #breedtobreathe campaign to highlight serious health issues breeds such as pugs and French bulldogs are prone to

Vets have urged dog-lovers to think twice about buying squashed-faced dogs such as pugs and French bulldogs, after many would-be owners were found to be unaware of the health problems such breeds often experience.

According to data from the Kennel Club, registrations of squashed-faced, or brachycephalic, breeds have shot up in recent years: while just 692 French bulldogs were registered in 2007, registrations reached 21,470 in 2016.

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Source: gad