Why do we only look to the stars for evidence of non-human sapience?
For some reason, nobody seems to have seriously considered the idea that Earthly creatures other than Home sapiens, including Homo sapiens sapiens and Homo sapiens neanderthalis, might have been technologically and culturally sophisticated beings. Proponents of extraterrestrial civilizations have SETI (the Search for ExtraTerrestrial Intelligence), and astronomers are now actively looking for evidence of life on extra-solar planets, but nobody seems to be looking for evidence of ancient terrestrial civilizations.
And even in the case of those looking for extraterrestrial life, none of them have proposed looking for evidence of one of life's important atmospheric signatures, the presence of by by-products of combustion, such as carbon monoxide, soot, and other chemical traces produced by fire. Without life, oxygen in large quantities can't be consistently present in a olanet's atmosphere; it can only be produced and maintained by the process of photosynthesis, which only living creatures are capable of. And without an atmosphere rich in oxygen, combustion isn't possible, as fire is the product of the chemical interactions of oxygen with carbon-rich mterials. If oxygen, or, even better, fire's by-products are evident in a planet's atmosphere over a significant period of time, then there has to be life on that world. But while astronomers are searching for evidence of significant amounts of atmospheric oxygen on extra-solar worlds, none of them seem to have realized that traces of the process of combustion would be even stronger indictors of life's presence on a world.
But the question remains: Why aren't we looking for evidence of some sort of advanced technology -- even something as simmple as the frequent use of artificially created fire for cooking or technological purposes -- among Earth's ancient life? Animal life has existed on our workd for at leasts 550 million years. In all that huge range of time, there could well have been ancient species -- cephalopods, non-avian dinosaurs, protomammals of the Prermian, ancient mammals of the Miocene, etc. -- which at least developed simple stone-bone-and-wood technologies. The only place I've ever seen even a mention of such a possibility was in a science-fiction novel, Stephen Baxter's Evolution. In that novel, which ranged back and forth among the ancient past, the present, and the future, at one point Baxter presents an episode involving relatively technologically advanced dinosaurs, who made spears and other tools from wood and other materials, used such tools to take down prey, and otherwise lived lives rather like those our ancestors of the Pleistocene or even Pliocene might have lived. But that was fiction, and no one else seems even to have considered that possibility, that ancient non-humans on our own world might have become relatively technologically advanced.
Why aren't we looking? Well, there are difficulties. A Paleolithic (Ancient Stone Age)-type culture would be crafting and using stone, bone, and wood tools for varous purposes. Fossils tend to be rare, anyway, and fossilized wood or bone tools would be far rarer. Tools could become badly worn and splintered and the pieces scattered, so that if any of them fossilized, they would look like that: so many random bits and pieces of once-living material, very llikely with no context to show that they were anything but time's usual detritus. As for stone tools, they would be made of shaped rocks. Those, too, would likely become worn and damaged with use or by accident, or even shattered into rubble. What context would there exist to show that they were ever anything more than typical rocks or bits of rock? If they managed to produce pottery or jewelry, would enough of it survive, in a telling matrix, to show what those things had originally been? And if they learned how to use fire, and harnessed it for cooking, technological processes, or other purposes, would anything beyond the random smear of soot or the like, which might look like nothing more than the remains of a forest fire or brush fire, survive the terrible pummeling of the ages?
And if, somehow, such a species evolved technologically to the point where it began smelting metals, would there be anything left clearly showing that such an achievement had been attained by that species?
Well, there might be. Pottery can be thick and clunky, and enough random chunks of a pot or other piece of pottery might turn up together in good enough shape to allow the finder to fit the pieces together to show what they had been part of. Jewelry made of semi-precious stones or even just pretty rocks that had been shaped and polished, then set into a necklace or bracelet made of vines or some stronger material might survive the ages, the stones themselves evidence of creatures that knew how to shape and polish them, and the settings indicated by the pattern of rock in which the stones were found.
As for fire, in his Fire: A Brief History, Stephen J. Pyne describes a cave in Africa in which the heaped-up remains of a great number of animals were found, the bones chewed by what were probably hyenas; the chwewed bones included the bones of hominids, creatures close kin to our ancient ancestors or among those ancestors themselves. Above that heap was a heavy streak of carbon on the wall of the cave, where fires must frequently have been set on a hearth of some sort. And above that streak were more bones -- but those bones had been cooked, ad while they included plenty of hyena bones, there were no hominid bones among them. That streak of carbon has been dated to 1.8 million years ago . . . So if Earth's ancient life learned to harness fire, there might well have been caves in which a similar trove of bones and a carbon layer representing a hearth could be found.
As for metals and metallurgy, consider this: Recent cores taken from the ice covering Greenland have been found to contain significant amounts of particles of industrial metals -- lead, iron, tin, copper, and others -- carried there by the winds. Those traces date back to the time of the Old Roman Republic and the Old Roman Empire, when metallurgy was relatively advanced and Rome's industries constantly processed metallic ores for a plethora of uses, including the making of tools, weapons, household goods, and many other things, the residues of which were picked up and carried by the winds of the world to Greenland and other parts of the Arctic. The thing is, those amalgams of those particular metals could never occur naturally, nor could a mixture of their ores. Only through processes carried out by living creatures could they have been created together, lofted into the air, and carried to places where they might settle and eventually be found. But you'd never discover such a thing unless a) you had an understanding of geological and industrial processes and what they can and cannot produce, and b) didn't believe that such a thing was impossible. Since people aren't looking for such residues -- or other evidence of technology among ancient life -- and don't believe that they and the technology necessary to produce them could have been possible among Earth's ancient life, they are not likely to find them. For similar reasons, they are not likely to find evidence of the existence of simpler technologies among ancient life, either.
Somewhere out there, astouding things could be waiting for us to discover them. Will we ever be open-minded enough to consider that they might exisst and that trying to find them would be a worthwhile endeavor? I hope so. I don't believe that we, as a species, are all alone in either space or time. Maybe it's time we revised our preconceptions and started looking closer to home for evidence of sapient life.
And even in the case of those looking for extraterrestrial life, none of them have proposed looking for evidence of one of life's important atmospheric signatures, the presence of by by-products of combustion, such as carbon monoxide, soot, and other chemical traces produced by fire. Without life, oxygen in large quantities can't be consistently present in a olanet's atmosphere; it can only be produced and maintained by the process of photosynthesis, which only living creatures are capable of. And without an atmosphere rich in oxygen, combustion isn't possible, as fire is the product of the chemical interactions of oxygen with carbon-rich mterials. If oxygen, or, even better, fire's by-products are evident in a planet's atmosphere over a significant period of time, then there has to be life on that world. But while astronomers are searching for evidence of significant amounts of atmospheric oxygen on extra-solar worlds, none of them seem to have realized that traces of the process of combustion would be even stronger indictors of life's presence on a world.
But the question remains: Why aren't we looking for evidence of some sort of advanced technology -- even something as simmple as the frequent use of artificially created fire for cooking or technological purposes -- among Earth's ancient life? Animal life has existed on our workd for at leasts 550 million years. In all that huge range of time, there could well have been ancient species -- cephalopods, non-avian dinosaurs, protomammals of the Prermian, ancient mammals of the Miocene, etc. -- which at least developed simple stone-bone-and-wood technologies. The only place I've ever seen even a mention of such a possibility was in a science-fiction novel, Stephen Baxter's Evolution. In that novel, which ranged back and forth among the ancient past, the present, and the future, at one point Baxter presents an episode involving relatively technologically advanced dinosaurs, who made spears and other tools from wood and other materials, used such tools to take down prey, and otherwise lived lives rather like those our ancestors of the Pleistocene or even Pliocene might have lived. But that was fiction, and no one else seems even to have considered that possibility, that ancient non-humans on our own world might have become relatively technologically advanced.
Why aren't we looking? Well, there are difficulties. A Paleolithic (Ancient Stone Age)-type culture would be crafting and using stone, bone, and wood tools for varous purposes. Fossils tend to be rare, anyway, and fossilized wood or bone tools would be far rarer. Tools could become badly worn and splintered and the pieces scattered, so that if any of them fossilized, they would look like that: so many random bits and pieces of once-living material, very llikely with no context to show that they were anything but time's usual detritus. As for stone tools, they would be made of shaped rocks. Those, too, would likely become worn and damaged with use or by accident, or even shattered into rubble. What context would there exist to show that they were ever anything more than typical rocks or bits of rock? If they managed to produce pottery or jewelry, would enough of it survive, in a telling matrix, to show what those things had originally been? And if they learned how to use fire, and harnessed it for cooking, technological processes, or other purposes, would anything beyond the random smear of soot or the like, which might look like nothing more than the remains of a forest fire or brush fire, survive the terrible pummeling of the ages?
And if, somehow, such a species evolved technologically to the point where it began smelting metals, would there be anything left clearly showing that such an achievement had been attained by that species?
Well, there might be. Pottery can be thick and clunky, and enough random chunks of a pot or other piece of pottery might turn up together in good enough shape to allow the finder to fit the pieces together to show what they had been part of. Jewelry made of semi-precious stones or even just pretty rocks that had been shaped and polished, then set into a necklace or bracelet made of vines or some stronger material might survive the ages, the stones themselves evidence of creatures that knew how to shape and polish them, and the settings indicated by the pattern of rock in which the stones were found.
As for fire, in his Fire: A Brief History, Stephen J. Pyne describes a cave in Africa in which the heaped-up remains of a great number of animals were found, the bones chewed by what were probably hyenas; the chwewed bones included the bones of hominids, creatures close kin to our ancient ancestors or among those ancestors themselves. Above that heap was a heavy streak of carbon on the wall of the cave, where fires must frequently have been set on a hearth of some sort. And above that streak were more bones -- but those bones had been cooked, ad while they included plenty of hyena bones, there were no hominid bones among them. That streak of carbon has been dated to 1.8 million years ago . . . So if Earth's ancient life learned to harness fire, there might well have been caves in which a similar trove of bones and a carbon layer representing a hearth could be found.
As for metals and metallurgy, consider this: Recent cores taken from the ice covering Greenland have been found to contain significant amounts of particles of industrial metals -- lead, iron, tin, copper, and others -- carried there by the winds. Those traces date back to the time of the Old Roman Republic and the Old Roman Empire, when metallurgy was relatively advanced and Rome's industries constantly processed metallic ores for a plethora of uses, including the making of tools, weapons, household goods, and many other things, the residues of which were picked up and carried by the winds of the world to Greenland and other parts of the Arctic. The thing is, those amalgams of those particular metals could never occur naturally, nor could a mixture of their ores. Only through processes carried out by living creatures could they have been created together, lofted into the air, and carried to places where they might settle and eventually be found. But you'd never discover such a thing unless a) you had an understanding of geological and industrial processes and what they can and cannot produce, and b) didn't believe that such a thing was impossible. Since people aren't looking for such residues -- or other evidence of technology among ancient life -- and don't believe that they and the technology necessary to produce them could have been possible among Earth's ancient life, they are not likely to find them. For similar reasons, they are not likely to find evidence of the existence of simpler technologies among ancient life, either.
Somewhere out there, astouding things could be waiting for us to discover them. Will we ever be open-minded enough to consider that they might exisst and that trying to find them would be a worthwhile endeavor? I hope so. I don't believe that we, as a species, are all alone in either space or time. Maybe it's time we revised our preconceptions and started looking closer to home for evidence of sapient life.