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Humans have always been self-absorbed, and it shows in the way we describe the world around us. Creation myths usually depict the culture in which the myth circulates as preeminent or “chosen” – in Deuteronomy 7:6, for instance, the Jews’ god announces that Jews are his chosen people. Until astronomical data proved otherwise, humans imagined that the Earth was the middle of the universe, and when that model proved empirically untenable, insisted that the sun was the universe’s center – the geocentric and heliocentric theories of astronomy, respectively. The mythology of the Blackfoot Indians provided that the creator had made birds and animals so that man could eat of their flesh. In the movie Jeremiah Johnson, a Rocky Mountain fur trader named Del Que rides into the foothills shouting, “I ain’t never seen them, but my common sense tells me that the Alps are foothills, and the Andes are for children to climb. Yes sir, these here Rocky Mountains are the marrow of the world!” When man describes the drama of the universe, he accords himself the central role.
But the geological record does not. According to present theory, Earth formed 4.5 billion years ago. Life appeared around 3.7 billion years ago. Multicellular organisms evolved around 1.8 billion years ago. Life crawled out of the seas and onto land for the first time about 500 million years ago, and dinosaurs waddled forth 230 million years before the present time. Anatomically modern humans emerged 400,000 years ago.
Some comparisons in raw numbers: crocodiles have been around for 200 million years. Trilobites, a group of three-lobed mud crawlers that looked like beetles but are now extinct, pulled off a phenomenal feat by lasting 340 million years. Blue-green algae has been around for a whopping 2.8 billion years. At 400,000 years, man has been around for 0.2% of the crocodile’s time, 0.11% of the trilobites’ time, and .01% of the algae’s time. To put it figuratively, using an analogy from Dave Brower as presented in John McPhee’s Encounters with the Archdruid: if one analogizes man’s evolution to the six days of Genesis, for all of Monday and Tuesday morning, Earth was lifeless. Life began on Tuesday at noon. At midnight on Wednesday, blue-green algae got started. At 4 PM on Saturday, dinosaurs and trilobites entered the scene, and five hours later, both were extinct. Three seconds before midnight – only three seconds before midnight – humankind emerged. We have not been here long enough to win the leading role in the Earthly drama.
And we will not be here much longer. Just as organisms die, species go extinct. Giant meteors like Chicxulub pound the earth; supervolcanoes like the Yellowstone hotspot explode; unknown conditions alter the atmosphere as with the rusting of the Earth in the late Archean; the climate changes drastically as with the Pleistocene ice ages. The more complex species, the faster it goes extinct. Mammals go extinct especially quickly. We’re the most complex mammal we know of. Our time on Earth is finite.
One slightly hung over morning when the coffee was late to arrive, I made this argument to my good friend Matt Stoddard. In a self-important moment, of which I have a regrettable plentitude, I said that no reasonable argument could be made to the contrary. He disagreed: humans would migrate from Earth when they needed to, he said. They would keep planet hopping and never go extinct. But the planethopping theory has a problem: for any given stretch of time, there is some probability that humankind will die out. To be charitable, let’s give humans a 0.1% chance of dying out in any given millennium. If we’re talking about whether man will ever go extinct – that is, planet-hopping indefinitely – then we’re talking about infinite time. Infinite time contains infinite millennia. So the chance that, in one millennium or another, man will eventually go extinct is infinity times 0.1%. Any number times infinity is infinity. The math: extinction is a certainty.
What will happen when humans no longer exist? Not much, probably. The crocodiles will keep swishing through warm salty water and cockroaches will crawl through our pantries. Or maybe the mode of our extinction will be dramatic enough to drag crocodiles and cockroaches down with us. In that case, the more primitive, sturdy forms of life may be all that remain: blue-green algae (aka cyanobacteria) might continue to add to the 2.8 billion years it has spent on Earth; the chemosynthetic microorganisms that live beside hydrothermal vents at the bottoms of the oceans might survive; so might the extremophilic microbes that live inside today’s nuclear reactors. In any case, the passing of Homo sapiens will be the norm rather than the exception – another mammal bites the dust.
And what if we managed to drag all life out of existence? The nonexistence of life wouldn’t be new. Earth existed for 800 million years without life, and the universe existed for about 9 billion years without Earth. Life is not indispensible to the operation of the cosmos. “Life” is, after all, only a label humans have given to a particular set of chemical patterns and reactions that we have observed on the surface of our own planet. The preoccupation with these particular patterns and reactions is, so far as we know, only a human fixation.
I pulled my jacket off the rack and walked outside with Duke. I could hear Otter Creek rippling in the darkness, could see the stars like so much silver confetti tossed across the sky. The cold night air slipped under my fleece and crept inside my pullover, cold against my lower back. Whatever the significance of the chemical patterns that make up my brain and body, and however long my species and I will continue to exist, it was a beautiful night. Duke sat beside me and looked up, waiting to be petted. What a blessing it is to have been included in the pageant of existence.
Cabin by night.
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