Apocalyptic lightning strikes caused our ancient ancestors to climb down from trees and start walking on 2 feet
A BARRAGE of lightning strikes triggered by huge cosmic blasts may have prompted our ancient ancestors to take their first steps millions of years ago.
That’s according to a shock new study, which says wildfires caused by brutal weather forced our monkey-like cousins to climb down from the trees and start walking on two feet.
Humans now have their hands free to build cathedrals, design rockets and snap selfies, say researchers.
“It is thought there was already some tendency for hominins to walk on two legs, even before this event,” said University of Kansas scientist Professor Adrian Melott.
“But they were mainly adapted for climbing around in trees. After this conversion to savanna, they would much more often have to walk from one tree to another across the grassland, and so they become better at walking upright.
“They could see over the tops of grass and watch for predators. It is thought this conversion to savanna contributed to bipedalism as it became more and more dominant in human ancestors.”
Our ancient ancestors lived among the trees and largely spent their time on the ground on all fours.
Just why they decided to hoist up on to two feet around 6million years ago remains a mystery.
Now, a cutting-edge study published in the Journal of Geology suggests for the first time that it was triggered by lightning-fuelled wildfires.
Professor Melott’s team say ancient exploding stars, or supernovae, gave “proto-humans” no choice.
They began blitzing Earth with energy up to 8million years ago – peaking around 5.4million years later.
It initiated an avalanche of electrons in the lower atmosphere – setting off a chain of events culminating in homo habilis.
Dubbed “handy man”, this is believed to be the earliest human species to leave tools – and leave Africa.
Based on a “telltale” type of metal which lines the world’s sea beds, it is known huge stars exploded 163 light years away between five and 2.5 million years ago.
The deposits of iron-60 were caused by supernovae in our cosmic neighbourhood.
This was during the transition from the warmer Pliocene Epoch to the beginning of the Ice Age.
Professor Melott said: “The more energetic ones from supernovae come right down to the surface, so there would be a lot of electrons being knocked out of the atmosphere.”
This meant an abundance of electrons would form more pathways for lightning strikes.
This spike set off wildfires around the world. The theory is supported by the discovery of carbon deposits found in soils that correspond with the timing.
Professor Melott said: “The observation is there is a lot more charcoal and soot in the world starting a few million years ago.
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“It is all over the place, and nobody has any explanation for why it would have happened all over the world in different climate zones. This could be an explanation.
“That increase in fires is thought to have stimulated the transition from woodland to savanna in a lot of places – where you had forests, now you had mostly open grassland with shrubby things here and there.
“That is thought to be related to human evolution in northeast Africa. Specifically, in the Great Rift Valley where you get all these hominin fossils.”
No such event is likely to occur again anytime soon. The nearest star capable of exploding into a supernova in the next million years is Betelgeuse, some 652 light years from Earth.
Added Professor Melott: “Betelgeuse is too far away to have effects anywhere near this strong. So, don’t worry about this.”
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