Were We the First Civilisation on Earth?

Our civilisation rose from a species that is the common ancestor of both us and a chimpanzee, and it lived just 6-8 million years ago. Once agriculture was developed, and we could set our minds to things other than hunting, it took only 10,000 years for us to make the world we see around us today. A total of just 8 million years separates a creature we typically recognise as being completely absent of sophisticated technology and culture, to having a high speed internet connection linking almost every home in the world. The history of life on Earth stretches back over 4 billion years. Is it possible that somewhere in that vast stretch of prehistory, there was another 10 million year period where some other life form developed a sophisticated civilisation such as ours?

Were we the first to claim the refinements of higher culture? (arms not to scale)

It is commonly held, and not without good reason, that homo sapiens are the architects of the first advanced civilisation that planet Earth has ever seen. We hold that we were the first to make tools from metal, the first to master agriculture and animal husbandry, the first to harness the power of atoms and the first to reach into space. It is a reasonable assumption to make. We certainly have no evidence of any other civilisation before ours. The human brain appears to have developed the sophistication required for civlisation only very recently (in planetary terms). Indeed, if there was an advanced civilisation before ours on Earth, would they not have influenced some aspect of the world for us to see today?

That is an important question. The ultimate hallmark of our civilisation has been our ability to shape the world around us. To alter our planetary signature. The evidence of our presence is very obvious when the Earth is observed from space. The gases in our atmosphere, the distribution of vegetation on the planet, the emission of highly ordered EM radiation from our planet’s surface. These indicators are so obviously the result of an advanced civilisation that they have been used as the basis for the methodology when looking for life on other worlds.

The Galileo space probe was launched in October 1989 and on it’s way to Jupiter performed a curious experiment. It used its sensors to scan for evidence of life, on Earth. The idea was that if we are going to use spectral analysis of a planet as a test for the presence of life, we should first calibrate that test to ensure it works. The test calibration was performed and we got our first baseline set of data. We could now go about searching for similar signs of thermodynamic disequilibrium, gaseous oxygen and high absorption of red light in alien atmospheres on our quest to find another pale blue dot out there in space.

Spacecraft Galileo had one last job to do before it left on it's way to Jupiter

The experimental basis is a sound one. We know of only one planet with life on it, and it forms our only frame of reference as we search for another. That is, for now at least. Such an experiment naturally looks out into the depths of space. Across distances so vast that even light takes millions of years to reach us. Such an experiment seeks to learn by observing the past. The farther away we look, the farther back we are seeing.

Here on Earth we are limited in our ability to look back into time. The light that left our world millions of years ago is forever lost to us. We can go only by the evidence that we have in our possession. But what is that evidence, and what does it tell us? We can approach this problem from another angle. Let us hypothesise for a moment that there had been an advanced technological civilisation here on this planet before us. How would we know about it today?

The most obvious suggestion would be fossil evidence. There might be fossils showing all of the adaptations we humans have come to rely upon; opposable digits, large brains, binocular vision, bipedal stance. There might also be evidence of organised burial rituals (assuming they can be considered a universal indicator of higher culture). Such forms of evidence are highly subjective, and anthropomorphic by even the most lenient standards. But just how much a reflection of the past is the fossil record in the first place? After all, we know that Tyrannosaurus Rex existed, but less than 50 skeletons have ever been found, and none of those are even complete. The key thing to note is that for fossilisation to occur, a very specific sequence of events must occur. For example, sediment must cover the remains of whatever died, or the body will decompose and be lost forever. Today, we know that T. Rex existed only because of all the thousands, perhaps millions of T. Rex that existed, fifty happened to fall dead near the water’s edge and were covered by sediment, and then were one day recovered by human hands. The simple fact is that fossilisation is actually quite a rare phenomenon. There are aspects of the process that bias certain life forms too, either due to the makeup of their bodies, the location in which they lived or indeed the environment in which they lived. Conventional wisdom holds that around 2% of the species that have ever lived have been fossilised in some form, somewhere on Earth. This leaves a large percentage that we will simply never know about. Let’s not also forget that we have assumed that this civilisation didn’t tend towards cremation or air burial of their dead for whatever reason. Such activities would of course completely eliminate any possibility of fossilisation. An otherwise empty cup of water drawn from a great ocean does not assure us that the ocean itself is empty.

Calcium based structures better lend themselves to fossilisation

What about the Galileo test. Atmospheric signatures created by industrial activities. Granted, human beings civilised about 10,000 years before we were able to significantly alter the atmospheric makeup of the planet. However, an atmospheric signature would meet the standard of evidence we have set in the search elsewhere in the universe. It would imply a thriving, long lasting civilisation. But how long after the fact could we expect this evidence to linger? The longest lasting greenhouse gases are thought to survive a few hundred years in our atmosphere. Slowly succumbing to breakdown of their molecular structure by the sun’s rays. Thermal equilibrium is also restored within a few hundreds of thousands of years following even the most extremely disruptive events, as is evidenced by geological records following the Yucatan meteor impact of 65 million years ago. By most estimates, if the human race were to disappear today, our planetary signature would be gone within 100,000 years. As such, we cannot rely on this to provide evidence of our existence to future civilisations beyond that.

Monuments. Whether they are simple campfires, tools or huge skyscrapers. The human race has left monuments to its presence all over the planet. Surely this is another piece of evidence that we could rely upon to tell us if we were the first to civilise on this planet? We have built monuments of stone and corrosion resistant alloy steel. Great dams and bridges, roads, settlements and highly ordered distributions of waste material. These might all be impressive achievements to some, but in terms of longevity they leave us wanting. Looking across the abandoned buildings of the once great Detroit automotive industry (here), it is very clear how quickly vegetation reclaims the land. Within the space of just a decade, the structures are at serious risk of total collapse. Plant roots and weather erosion are reducing reinforced concrete to rubble at an alarming rate. Within 50 years little will be left beyond piles of rubble, and within 1000 years we can expect even the rubble to have been overrun by nature. The same basic forces work their way at all of our monuments. The great pyramid complex of Giza has stood for 45 centuries, and stands today. The dry desert environment has limited the effects of water erosion to some extent. However, even this mighty monument of human achievement is not immune to the ravages of time, as can clearly be seen. Stone monuments such as the pyramids and Stonehenge are more resistant to the effects of neglect than most modern materials, such as steel. In essence they are formed of a more stable composition of matter. But given a few hundred thousand years, even stones will turn to gravel and then eventually, to dust. The finest stainless steels, the miracle materials of the modern age, while strong and light, are not totally immune to corrosion. In even the most favourable of conditions, and considering the finest of steels, a millimeter is still lost to corrosion over the course of a thousand years. This means that if the pyramids had been made using 2'' thick stainless steel plate, and maintained as well as the stone pyramids have been, they would no longer exist in just 50,000 years..

Then there is the matter of the canvas itself. Over the course of millions of years, tectonic plates shift land masses across the globe. The Earth’s crust is constantly being consumed in some areas, and created anew in others. Seabeds become mountain tops, and great plains find their way to the bottom of oceans. The effects of the natural processes of our planet can eliminate not only the monuments we create, but can absolutely consume the very ground they were built upon.

In fact, therein lies the key factor. Assuming that a previous civilisation had existed, we would be hard pressed to find any evidence of them here on Earth at all. Between the various difficulties in creating enduring evidence, and the highly volatile nature of the planet’s surface we cannot reasonably expect to find evidence today, even if it had once existed, except by an extraordinary stroke of luck. 98% of the dinosaur species will speak to that effect. An observation of our own development also seems to indicate that upon reaching a certain technological level, a civilisation might move towards a more sustainable and ecologically sound existence. They very nature of which would serve to lighten the footprints of such a civilisation. This significantly curtails the window of time for which a civilisation might leave lasting traced of itself.

Indeed, if were to take our own example and look forward to what we might leave behind, then there are precious few achievements that we can hope to carry our torch into the distant future. There is the Voyager and Pioneer space probes. Each carrying a golden record, ensuring the words of our people and the music of Chuck Berry and JS Bach (amongst others) will outlast even our solar system. There is the ever so faint halo of radio waves we emanate, for a brief moment before we transition to more efficient communication technologies. Both the probes and the waves would not be available to future Earthbound civilisations, but might one day hope to meet scientists from other worlds.

The single nearby piece of lasting evidence of our existence would seem to be some small flags, a few footprints, a few landers and an electric car left on the Moon by space programmes of our time. The Moon is free of weather and tectonic effects. While moonquakes do occur, they are very weak and pose little threat to the items we have left on it’s surface. The lack of atmosphere makes the surface of the moon an inert place. Indeed, we can reasonably assume our landers will remain intact until the sun transitions into a red giant, some 3.5 billion years from now. Perhaps quite aptly, the most enduring evidence of our existence is likely to be our crowning achievement as a civilisation. However, the surface of the moon, while mapped, has not been explored in detail. While it is reasonable to assume that there is nothing there to be found, it is here that we are most likely to find evidence of any prior Earth civilisation, provided they managed to attain the same heights we had by the late 1960s.

Footprint on the Moon

The argument that we are the first because we can see no evidence of any others sounds remarkably similar to the we are the only sentients life forms, because we can see no others. The natural egoentric persuasions of the human mind lend themselves well to this type of thinking. However, it was proven that we are not the center of the solar system, and it was proven that we are not the center of the universe. Even when the evidence was in hand, it took many years to convince the world at large of these facts. This should be the most telling example of our prejudices with regards to any information that demotes our position in this world. I propose that we may not even hold the title of first and foremost on our very own soil. I can offer no evidence, and set forward only a hypothesis. One that can be tested, and certainly will be over the coming years. Until then, I can’t help but be curious what might have happened on this planet before we arrived, and what might have happened that we would be given our chance on this Earth. If nothing else, it makes for great fantasy.