Five major extinction events: Orodovician, Devonian, Permian Triassic, and Cretaceous. Most people know about the last one because the dinosaurs kicked the proverbial bucket 65 million years ago. Since then, there have been catastrophes of various kinds, but nothing that ranks with the five events, one of which, the Permian some 252 million years ago, eliminated most species (maybe up to 90% of them). And, who knows? We might be living through a sixth mass extinction, though being in the middle of something makes seeing it holistically difficult.
Nevertheless, you are safe for now, well, not you individually sorry to say, but your species. It hasn’t had to deal with a 6-mile-diameter comet impact like the one that occurred 65 million years ago, and it hasn’t had to deal with an atmosphere with a low-oxygen content like the air of 252 million years ago. Yes, our species has been hit by a number of disasters like the plague and large volcanic eruptions like that of Toba 74,000 years ago, but nothing global in nature that destroyed large numbers of life-forms in a brief time. Even if we are forcing a number of big organisms out of existence (the last male northern white rhino just kicked the same bucket the dinosaurs kicked—and don’t forget the poor Dodo), we might not be eliminating much of the world’s cryptofauna, small fauna, flora, and micro-fauna. Bacteria, for example, have long ruled our planet—hope that’s not a blow to your ego, but the little critters can even be found in long buried and miles-deep rocks, well out of reach of any destructive human madness.
Of course, there are those who proclaim that your species is in dire straits: Increased carbon dioxide, potentially increasing methane, and increasing amounts of pollutants inimical to animal health. Then there are those pesky nuclear weapons in the hands of a species that doesn’t always exhibit an emotional calm. And don’t forget the potential for 999042 Apophis or some other passing body to collide with the planet ala the Cretaceous impactor.
Wait! Am I just making an argument that you aren’t personally safe? What am I doing? The title of this little essay suggests that safety is attainable.
In fact, you--personally You—are relatively safe from most natural “big events.” The probability of any natural disaster affecting you is low, though not nonexistent. Apophis will probably miss Earth when it passes in 2029 and again in 2036. There are windows of safety that stretch 11 years and 18 years at the time of this writing. It’s only a little over 2 miles wide, anyway, so what’s that in comparison to the Cretaceous impactor that made the Chicxulub crater (about 100 miles in diameter)? Yeah. Little impactors strike the planet every year, but big ones rarely do. And with extinctions? Well they occur on average once every 100 million years. Even the Yellowstone supervolcano seems to be on a 600,000-year eruption cycle (Oh! I just remembered: The last such eruption occurred 600,000 years ago).
This isn’t getting any better, is it? And I didn’t even mention the potential rise of “superbugs,” bacteria and viruses that are immune to antibiotics and vaccines. Well, at least, there’s been only one tragic death by a self-driving Uber.
Do you not find it interesting that in a world fraught with various avenues to individual and species extinction, that humans continue to take unnecessary risks? This isn’t any individual’s practice life. Species can practice and lose members, but individual members can’t practice and fail. Genera can practice. You personally really can’t. A genus can lose most of its species, but still survive in one, say, like the Albany pitcher plant or the cream-spotted cardinalfish. Of course, there’s always an exception of longevity like the Ginkgo biloba, the sole survivor of a genus that has survived three of the mass extinctions.
But you would probably note that having just one species doesn’t bode well for most genera. And, you would probably note that, come to think of it, Homo sapiens sapiens is the only species left in our genus. H. habilis, H. erectus, H. heidelbergensis, H. naledi, Cro-magnon, and H. neaderthalensis are all gone like the dinosaurs, never to return—regardless of some mad scientist’s future efforts to revive their genomes. Those sister species practiced and lost the game of continued existence.
Back to that question: Isn’t it interesting that humans continue to take risks that might eliminate not just themselves, but all humans?
You know as I do that no one can eliminate all risks, but isn’t there something we can do to preserve the species a little while longer? (Ginkgo biloba and horseshoe crabs aside, the average lifespan of species is probably about 4 million years thanks to those long-lived species; but humans are just pushing about 300,000 or so, and look what’s happened to our sister species, not one of which met that average lifespan)
Here’s a modest proposal. Start in preschool to teach mass extinctions, not just dinosaur extinctions, but other extinction events. And adopt a view held by the late Stephen Gould, who entitled his widely-read book Wonderful Life. Gould argued that since the number of body forms (phyla) are limited, that any past extinction event could have wiped out descendants. If that early vertebrate Pikaia—our ancestor—had been killed in a local or global disaster, then I wouldn’t be here to write this, and you wouldn’t be here to read it. All versions of the vertebrate body form subsequent to Pikaia wouldn’t exist. And then, as Gould writes, the descendants of Pikaia had to pass through the filter of five major extinction events, any one of which could have stopped the phylum from evolving.
Maybe if children understood early on that unnecessary risk, though sometimes as exhilarating as skydiving, is personally dangerous and possibly inimical to the species, they would form the first generation ever that eliminated the risks they could control. Maybe they would understand that this isn’t a practice life for any individual--or species.
“Whoa!” you say. “You want the world to be a boring place. Surely, you’ve flown and broken the speed limit in your car. You’ve gone scuba diving. You’ve played sports like football and faced baseball pitchers throwing a hard sphere very near your head.”
No, I don’t want boredom, but boredom is a relative matter. There are times and places where preservation takes precedence over risk and thrill, over escapism and foolhardiness. Accidents and disease will always be with us. Living in three-dimensional space means that there will probably be some bump to trip us when we jog. However, celestial impactors will rarely hit, and long-term changes to the planet will occur beyond our individual lifetimes. By comparison, foolish risks are largely avoidable, and youth who learn that principle and the principle that this is not a practice life, might stretch their personal existence toward a natural biological end caused by shortening telomeres or one caused by an unavoidable incoming asteroid.