Consider a planet earth as a place where evolutionary change occurred up to the point where the tree of life branch we now call Homo did not actually appear: no genus Homo, and of course, no species called Homo sapiens. A world without people, a world without us. If you can imagine hiking alone in the mountains or standing on a lonely beach, you’re getting the idea. Then imagine turning completely around and seeing no other person, no houses, roads or trails, no works of humans of any kind. You’re getting closer. Finally, take yourself out of the picture. As you fade into nothingness, remember this: The ocean, the mountains, the prairies, and the forests are still there. The wind rustles the leaves on the trees, the ocean waves break on the rocks, the sun travels across the sky, darkness arrives and with it the moon and the stars. When the sun is out, it shines on the green leaves of billions of plants, and it shines on things that move around and make noise- animals. There are also creatures that usually can’t be seen, such as bacteria and viruses, except when they infect plants or animals.
How would all these creatures fare without us? Quite well, I imagine, and why not? They got along without us for over three billion years. Then, about 600 million years ago there was an explosion of life of all kinds. Eventually, and perhaps unfortunately, evolution tossed up H. sapiens. Members of our species immediately got to work destroying the planet, and have faithfully continued on that mission ever since. Humans are irrelevant at best, and disastrous at worst for the welfare of all other living things. Without us, animals would eat, sleep, and roam, just as they do now. Plants would absorb light from the sun and chemical nutrients from the soil, the water and even the air. They would all grow and reproduce, and do all the things we observe them doing now, except that nobody would write a book or give a speech, or make a movie about what happens. Best of all, no one would have weapons with which to try to kill all the American bison, or cut down all the trees. There would be no books, no television, no vehicles, no products of human intelligence and ingenuity. What a loss, you say. Why? Who will need any of those things? None of the creatures read, let alone understand language. Lions have no interest in the life history of the zebras or wildebeests or gazelles that they eat. Not a single creature would ask: How come I have to live in this dry, hot desert when all those other guys live in trees, or the air, or the ocean? Not one would need to be entertained, or educated, or fed, or photographed.
A world without people can come about in two ways. The first is a planet, earth, on which a great war or plague wipes out seven billion people (the latest count-estimate of all those that exist here now). What remains will include some of the artifacts that we have created and many of the other living creatures, plants, animals, and micro-organisms that survived. The face of the planet- the land, mountains, oceans and seas, atmosphere, would survive, relatively intact, only needing to endure storms, volcanoes, tectonic plate movement, and occasional ice ages. Can the catastrophe that creates this scenario be avoided? Perhaps, if humanity overcomes its own stupidity, blindness, and indifference. A very tall order, I think.
The other would have had to start with the first life on earth, and continue through millions of years of evolution, but not lead to the appearance and development of human beings. How does this kind of world come about? First, the human species is not the necessary expected result of a purposeful climb upwards. The human species is at the end of one branch of the tree of life. Suppose that branch stopped growing before our appearance. Other branches have different endpoints-dolphins, chickens, roses, E. coli. Would one of those branches produce some sort of superior being as a substitute for us? Perhaps, but not necessarily so.
Are there any other worlds in the galaxy, in the universe, that have developed in an evolutionary fashion of some sort? Maybe. We may never know. On one hand, we have science fiction. On the other, reality, and our ignorance of it.
Let’s consider some numbers. According to the Big Bang theory, the observable universe is more than thirteen billion years old. The number of stars may be as high as 300 sextillion. The number of stars similar to our sun has been estimated at about 23% of the total, or about 69 sextillion (69 followed by 21 zeroes). That’s a lot of suns. These numbers are calculated estimates but the true numbers are probably in the same ballpark, albeit a very big ballpark.
When we contemplate the existence of other populated planets, we almost always focus on worlds more advanced than this one. If such worlds exist, what would they be like? They would almost certainly have microorganisms and plants of various kinds. Animals? Maybe. Maybe not. Would they have humans or other sentient types like us? If those planets are truly more advanced than ours, some of their creatures would be far superior to the human race. If that superiority did not include the need and means to conquer or destroy, the length of their existence as inhabited planets could well be until the time when their suns flame out and die. There is also the possibility that a natural catastrophe could occur, such as a giant meteor crashing into a planet, obscuring the light from its sun, and killing all life. These very superior beings would not likely be responsible for wars, greed, poverty, pollution and other insults to their planet and to themselves that could destroy their planet.
Now let us suppose there is somewhere a planet identical to Earth, except for one primary difference: there are no humans. There are also no buildings, no roads, no railroad tracks, no boats or ships, no airports and airplanes, no power poles or wires, nothing underground except for natural caves, no guns or knives or axes, and the only “wars” are minor skirmishes between two ape or monkey colonies. There are also no banks, no money, no credit cards, not one single product of human imagination and intelligence, including no products of human greed, irrationality, or hunger for power. No crime of any kind. The air and the water and the soil are untainted by human pollution. Slums don’t exist, nor mansions. The only climate changes are the natural changes created by the planet itself.
What is left? Nature itself and its beauty. But what good is it, you may ask, if there is nobody there to see the beauty? Oh, gosh! But consider this: There is also no ugliness and no irreparable damage caused by one species alone –Homo sapiens. Thus I say flatly, our loss, our absence, is every other living creature’s gain.
What is there to hope for? On this planet, barring a miraculous change in the human character, probably nothing. We can hope that elsewhere there are planets with no sentient beings, or perhaps, with sentient beings minus the genes of wickedness that would enable them to destroy their own planetary home. If so, perhaps they may some day come here, view the devastation, shake their heads and murmur, “Poor fools.”