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posted by martyb on Thursday May 30 2019, @12:44AM   Printer-friendly
from the Hulking-discovery dept.

Exploding stars led to humans walking on two legs, radical study suggests

It was the evolutionary leap that defined the species: while other apes ambled around on all fours, the ancestors of humans rose up on two legs and, from that lofty position, went on to conquer the world.

The benefits of standing tall in the African savannah are broadly nailed down, but what prompted our distant forebears to walk upright is far from clear. Now, in a radical proposal, US scientists point to a cosmic intervention: protohumans had a helping hand from a flurry of exploding stars, they say.

According to the researchers, a series of stars in our corner of the Milky Way exploded in a cosmic riot that began about 7m years ago and continued for millions of years more. The supernovae blasted powerful cosmic rays in all directions. On Earth, the radiation arriving from the cataclysmic explosions peaked about 2.6m years ago.

The surge of radiation triggered a chain of events, the scientists argue. As cosmic rays battered the planet, they ionised the atmosphere and made it more conductive. This could have ramped up the frequency of lightning strikes, sending wildfires raging through African forests, and making way for grasslands, they write in the Journal of Geology. With fewer trees at hand in the aftermath, our ancient ancestors adapted, and those who walked upright thrived.

Also at University of Kansas and Discover Magazine.

From Cosmic Explosions to Terrestrial Fires? (DOI: 10.1086/703418) (DX)


Original Submission

 
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  • (Score: 4, Insightful) by The Shire on Thursday May 30 2019, @05:16AM (1 child)

    by The Shire (5824) on Thursday May 30 2019, @05:16AM (#849196)

    This is not science, this is pure conjecture. They have no evidence that supernovae have any influence on Earth at all let alone enough to make a wild and totally unsubstantiated statement like it caused bipedalism. A supernova is a catchy headline, and they briefly release a great deal of energy, but the inverse square law applies here. The explosions are big, but the distances are bigger. By the time any remnant arrives at our solar system it's virtually incapable of getting past the heliosphere.

    Science is about having a theory and then backing it up with reproducable evidence. What we have here are some bored researchers scribbling on napkins while getting plastered on gin and tonics and that the media then attaches a catchy title to in order to get click through revenue. This is sadly how most "science" is reported today. Grab some ludicrous conjecture, slap an eye catching headline on it, and bam - click revenue. Never mind that it's all a lie, they get their money. Journalistic and even scientific integrity be damned.

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  • (Score: 3, Insightful) by AthanasiusKircher on Thursday May 30 2019, @10:56PM

    by AthanasiusKircher (5291) on Thursday May 30 2019, @10:56PM (#849465) Journal

    Welcome to the world of evolutionary biology, where "science" has been done like this for generations. Note I'm not at all criticizing the core idea of evolution, but evolutionary biology has a marked propensity for using what are known as "just so stories," i.e., "we don't know what happened, but I'll make up a plausible story that it might have happened just so..." as an explanation for how/why something evolved.

    Most of the times these are based on little evidence and a lot of conjecture. But it's how a certain breed of evolutionary biologists passes time.