Has life started many times of Earth? Could life as we know it today on our pale blue dot in fact be a second genesis? Could Earth’s original microbial life have formed four billion years ago, only to be destroyed some ten million years later during the age of Late Heavy Bombardment by massive asteroids sterilizing the planet? But perhaps some of this primordial “life as we don’t it” survived the 200-million-year barrage of huge objects followed by a second genesis of microbial life representing our form of life co-existing to this day with a “shadow biosphere” of Earth’s original alien life forms.
“If life can happen twice, it can surely happen a zillion times,” says astrophysicist Paul Davies. And that single alien microbe from early Earth –the hidden shadow biosphere–that may be intermingled with our current genesis, “doesn’t have to be on some far-flung planet; it could be here on Earth. upending our vision of the cosmos and mankind’s place within it and greatly boosting the prospect that intelligent life may be out there somewhere.”
Looking back over the past 3.5 billion years, the origin of life was the first, and most momentous, transformation followed by major transitions, “sofware upgrades”, without which further advance would be impossible from the arrival of eukaryotes, to sex, followed by the leap from unicellularity to multicellularity.leading to the epic, seminal upgrade that began about 500 million years ago with the appearance of a primitive central nervous system and the human brain –the most complex information-processing system known–.and the most mysterious phenomenon of all in “life’s magic puzzle box” – consciousness, the ghost in the machine.
“Regarding the nature of the very foundation of mind, consciousness, we know as much as the Romans did: nothing.” quotes Davies. It’s the central mystery of our time, that physicists suggest may exist by itself, even in the absence of matter, just like gravitational waves, –excitations of spacetime– that may exist in the absence of protons and electrons.
The Daily Galaxy, Max Goldberg, via Paul Davies, The Demon in the Machine, University of Chicago Press. Kindle Edition and Nature
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