On the rarity of human life ...
And so, this ...
... add to that, of course, the even greater seeming improbability of your own individual birth, dependent on every twist and turn of human history, and your personal ancestral genetic chain, since this rather hospitable planet popped up where it did in the 'goldilocks zone' of our solar system (not to mention the advent thereon of any genetic chains at all!): Every parent and grandparent and their grandparents in your family tree who fell in love and into bed on a certain night, every single mammalian or piscene or eukaryote ancestor of yours over millions and a couple of billions of years who happened to crawl, swim or slither to the left and the breeding ground, and not to the right and the clutches of a waiting predator!
Heck, a good case can be made that countless events of history ... both the happy and the sad, the pageants and peach blossoms, plagues and pogroms (alas) ... would have had to have been more or less just as they were lest history had wandered off in some other direction ... with your ancestors in tow, and thus without you.
So ... whether there is or is not intelligent life on another planet or countless planets, it seems certain that your personal life, here and now, is incredibly rare. I am convinced that something more is afoot, some as yet undiscovered physical process behind the scenes, some magic trick pulling the rabbit (you) out of life's hat, so that the dice are a bit more loaded than they appear, the seemingly avoidable more inevitable than on first blush, with our conscious awareness right now having more to it than meets the eye. Still, no matter the odds, one can easily imagine that this universe could have been on its merry way, and gotten along quite well without you and me, thank you, so it is some wonder that we should be here to imagine that fact at all. Yet, here we are.
So, live gently ... with grace and appreciation. As the Buddha taught: Don't blow it.
Gassho, J
STLah
In the Mahaparinirvana Sutra, the Buddha used the metaphor of a blind turtle in a vast ocean to explain how difficult it is to be reborn as a human being.
Suppose there is a small piece of wood floating on a vast ocean. The wood has a small hole the size of which is just enough for the head of a turtle to pop into. There is a long-lived sea turtle in the ocean. Once every one hundred years, this turtle comes out from the bottom of the ocean perchance to pop his head into the hole of the wood. To be born as a human being is just as hard as for the blind turtle to encounter the small piece of wood on a vast ocean and let its head go through the hole in the wood piece.
Suppose there is a small piece of wood floating on a vast ocean. The wood has a small hole the size of which is just enough for the head of a turtle to pop into. There is a long-lived sea turtle in the ocean. Once every one hundred years, this turtle comes out from the bottom of the ocean perchance to pop his head into the hole of the wood. To be born as a human being is just as hard as for the blind turtle to encounter the small piece of wood on a vast ocean and let its head go through the hole in the wood piece.
Humans May Be the Only Intelligent Life in the Universe, If Evolution Has Anything to Say
By Nick Longrich - Senior Lecturer, Paleontology and Evolutionary Biology, University of Bath
Are we alone in the universe? It comes down to whether intelligence is a probable outcome of natural selection, or an improbable fluke. By definition, probable events occur frequently, improbable events occur rarely — or once. Our evolutionary history shows that many key adaptations — not just intelligence, but complex animals, complex cells, photosynthesis, and life itself — were unique, one-off events, and therefore highly improbable. Our evolution may have been like winning the lottery … only far less likely. ... Could intelligence simply be unlikely to evolve? Unfortunately, we can't study extraterrestrial life to answer this question. But we can study some 4.5 billion years of Earth's history, looking at where evolution repeats itself, or doesn't
Evolution sometimes repeats, with different species independently converging on similar outcomes. If evolution frequently repeats itself, then our evolution might be probable, even inevitable. ... Here's the catch. All this convergence happened within one lineage, the Eumetazoa. Eumetazoans are complex animals with symmetry, mouths, guts, muscles, a nervous system. Different eumetazoans evolved similar solutions to similar problems, but the complex body plan that made it all possible is unique. Complex animals evolved once in life's history, suggesting they're improbable.
... Surprisingly, many critical events in our evolutionary history are unique and, probably, improbable. One is the bony skeleton of vertebrates, which let large animals move onto land. The complex, eukaryotic cells that all animals and plants are built from, containing nuclei and mitochondria, evolved only once. Sex evolved just once. Photosynthesis, which increased the energy available to life and produced oxygen, is a one-off. For that matter, so is human-level intelligence. There are marsupial wolves and moles, but no marsupial humans.
There are places where evolution repeats, and places where it doesn't. If we only look for convergence, it creates confirmation bias. Convergence seems to be the rule, and our evolution looks probable. But when you look for non-convergence, it's everywhere, and critical, complex adaptations seem to be the least repeatable, and therefore improbable.
What's more, these events depended on one another. Humans couldn't evolve until fish evolved bones that let them crawl onto land. Bones couldn't evolve until complex animals appeared. Complex animals needed complex cells, and complex cells needed oxygen, made by photosynthesis. None of this happens without the evolution of life, a singular event among singular events. All organisms come from a single ancestor; as far as we can tell, life only happened once.
Curiously, all this takes a surprisingly long time. Photosynthesis evolved 1.5 billion years after the Earth's formation, complex cells after 2.7 billion years, complex animals after 4 billion years, and human intelligence 4.5 billion years after the Earth formed. That these innovations are so useful but took so long to evolve implies that they're exceedingly improbable.
These one-off innovations, critical flukes, may create a chain of evolutionary bottlenecks or filters. If so, our evolution wasn't like winning the lottery. It was like winning the lottery again, and again, and again. On other worlds, these critical adaptations might have evolved too late for intelligence to emerge before their suns went nova, or not at all.
Imagine that intelligence depends on a chain of seven unlikely innovations — the origin of life, photosynthesis, complex cells, sex, complex animals, skeletons and intelligence itself — each with a 10% chance of evolving. The odds of evolving intelligence become one in 10 million.
But complex adaptations might be even less likely. Photosynthesis required a series of adaptations in proteins, pigments and membranes. Eumetazoan animals required multiple anatomical innovations (nerves, muscles, mouths and so on). So maybe each of these seven key innovations evolve just 1% of the time. If so, intelligence will evolve on just 1 in 100 trillion habitable worlds. If habitable worlds are rare, then we might be the only intelligent life in the galaxy, or even the visible universe.
And yet, we're here. ...
https://www.livescience.com/evolutio...gent-life.html
By Nick Longrich - Senior Lecturer, Paleontology and Evolutionary Biology, University of Bath
Are we alone in the universe? It comes down to whether intelligence is a probable outcome of natural selection, or an improbable fluke. By definition, probable events occur frequently, improbable events occur rarely — or once. Our evolutionary history shows that many key adaptations — not just intelligence, but complex animals, complex cells, photosynthesis, and life itself — were unique, one-off events, and therefore highly improbable. Our evolution may have been like winning the lottery … only far less likely. ... Could intelligence simply be unlikely to evolve? Unfortunately, we can't study extraterrestrial life to answer this question. But we can study some 4.5 billion years of Earth's history, looking at where evolution repeats itself, or doesn't
Evolution sometimes repeats, with different species independently converging on similar outcomes. If evolution frequently repeats itself, then our evolution might be probable, even inevitable. ... Here's the catch. All this convergence happened within one lineage, the Eumetazoa. Eumetazoans are complex animals with symmetry, mouths, guts, muscles, a nervous system. Different eumetazoans evolved similar solutions to similar problems, but the complex body plan that made it all possible is unique. Complex animals evolved once in life's history, suggesting they're improbable.
... Surprisingly, many critical events in our evolutionary history are unique and, probably, improbable. One is the bony skeleton of vertebrates, which let large animals move onto land. The complex, eukaryotic cells that all animals and plants are built from, containing nuclei and mitochondria, evolved only once. Sex evolved just once. Photosynthesis, which increased the energy available to life and produced oxygen, is a one-off. For that matter, so is human-level intelligence. There are marsupial wolves and moles, but no marsupial humans.
There are places where evolution repeats, and places where it doesn't. If we only look for convergence, it creates confirmation bias. Convergence seems to be the rule, and our evolution looks probable. But when you look for non-convergence, it's everywhere, and critical, complex adaptations seem to be the least repeatable, and therefore improbable.
What's more, these events depended on one another. Humans couldn't evolve until fish evolved bones that let them crawl onto land. Bones couldn't evolve until complex animals appeared. Complex animals needed complex cells, and complex cells needed oxygen, made by photosynthesis. None of this happens without the evolution of life, a singular event among singular events. All organisms come from a single ancestor; as far as we can tell, life only happened once.
Curiously, all this takes a surprisingly long time. Photosynthesis evolved 1.5 billion years after the Earth's formation, complex cells after 2.7 billion years, complex animals after 4 billion years, and human intelligence 4.5 billion years after the Earth formed. That these innovations are so useful but took so long to evolve implies that they're exceedingly improbable.
These one-off innovations, critical flukes, may create a chain of evolutionary bottlenecks or filters. If so, our evolution wasn't like winning the lottery. It was like winning the lottery again, and again, and again. On other worlds, these critical adaptations might have evolved too late for intelligence to emerge before their suns went nova, or not at all.
Imagine that intelligence depends on a chain of seven unlikely innovations — the origin of life, photosynthesis, complex cells, sex, complex animals, skeletons and intelligence itself — each with a 10% chance of evolving. The odds of evolving intelligence become one in 10 million.
But complex adaptations might be even less likely. Photosynthesis required a series of adaptations in proteins, pigments and membranes. Eumetazoan animals required multiple anatomical innovations (nerves, muscles, mouths and so on). So maybe each of these seven key innovations evolve just 1% of the time. If so, intelligence will evolve on just 1 in 100 trillion habitable worlds. If habitable worlds are rare, then we might be the only intelligent life in the galaxy, or even the visible universe.
And yet, we're here. ...
https://www.livescience.com/evolutio...gent-life.html
Heck, a good case can be made that countless events of history ... both the happy and the sad, the pageants and peach blossoms, plagues and pogroms (alas) ... would have had to have been more or less just as they were lest history had wandered off in some other direction ... with your ancestors in tow, and thus without you.
So ... whether there is or is not intelligent life on another planet or countless planets, it seems certain that your personal life, here and now, is incredibly rare. I am convinced that something more is afoot, some as yet undiscovered physical process behind the scenes, some magic trick pulling the rabbit (you) out of life's hat, so that the dice are a bit more loaded than they appear, the seemingly avoidable more inevitable than on first blush, with our conscious awareness right now having more to it than meets the eye. Still, no matter the odds, one can easily imagine that this universe could have been on its merry way, and gotten along quite well without you and me, thank you, so it is some wonder that we should be here to imagine that fact at all. Yet, here we are.
So, live gently ... with grace and appreciation. As the Buddha taught: Don't blow it.
Gassho, J
STLah
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