In 1974, the fossilised bones of Lucy, a 3.2 million-year-old hominin, were discovered in Ethiopia. How has this remarkable skeleton disproved Darwinian theory – and what links her to the Beatles?

On 24 November 1974, the US anthropologist Donald Johanson was scrabbling through a ravine at Hadar in the Afar region of Ethiopia with his research student, Tom Gray. The pair were looking for fossilised animal bones in the surrounding silt and ash when Johanson spotted a tiny fragment of arm bone – and realised it belonged to a human-like creature.

“We looked up the slope,” Johanson later recalled. “There, incredibly, lay a multitude of bone fragments – a nearly complete lower jaw, a thighbone, ribs, vertebrae, and more! Tom and I yelled, hugged each other, and danced, mad as any Englishman in the midday sun!”

Study shows population on Arctic island was stable until sudden demise, countering theory of ‘genomic meltdown’

The last woolly mammoths on Earth took their final stand on a remote Arctic island about 4,000 years ago, but the question of what sealed their fate has remained a mystery. Now a genetic analysis suggests that a freak event such as an extreme storm or a plague was to blame.

The findings counter a previous theory that harmful genetic mutations caused by inbreeding led to a “genomic meltdown” in the isolated population. The latest analysis confirms that although the group had low genetic diversity, a stable population of a few hundred mammoths had occupied the island for thousands of years before suddenly vanishing.