“There’s no shortage of ‘End of the World’ scenarios: Fire, Ice, Pandemic, Solar Flares, Supernova Gamma Ray Burst, Mega Caldera Eruption, Global Nuclear War, Giant Asteroid or comet Impact, Global warming. Rocks ominously whisper to us of primordial cataclysmic global events. Ancient bones sheathed in rock bring to mind the final deathblow to the dinosaurs. So far, all earth’s mass life extinctions have occurred prior to The Age of Man. But in addition to the threat of global warming, there looms a mass life extinction event that will certainly extinguish humanity forever in a geological heartbeat unless it is prevented.”
When I was in high school, I first heard that the genesis of life occurred in a “primordial soup, probably energized by a bolt of lightning.” Well…that’s kind of vague. The ‘primordial soup,’ (with or without ‘lightning’) is better described as biospheric factors that played titanic roles during much of the dawn of life. Those factors include: Marine Anoxia, Freed Oxygen, Photosynthesis, Greenhouse Gases, Ocean Acidification, asteroid impacts, Volcanism, and ─ not the least of factors ─ the voracious appetite of methanogenic bacteria and their dinner habits. I’m not kidding. Methanogenic bacteria relish methane.
[Note: the hypothetical comet or asteroid cited above is not the one associated with the extinction of the dinosaurs only 65 million years ago when they had already been in decline for millions of years. The Yucatan asteroid ─ as I call it ─ ended the dinosaurs’ already weakened species as a result of various causes.]
End Permian ─ Triassic Period, also known as, The Great Dying.
There have been several mass life extinctions, the most devastating of which occurred at the geologic borderline between the Permian and Triassic Periods and whose global devastation lasted for about fifty million years (300-252 million years ago). Causes of that apocalyptic event include: 1) Two million years of massive volcanic activity, combined with the gluttony of methanogenic bacteria who convert carbon dioxide to methane, or 2) One million square miles of deep lava flows ─ the size of present Europe ─ packed with nickel-eating bacteria, or 3) A possible asteroid impact at the end of the Triassic Period that penetrated the bottom of the earth’s upper mantle, or 4) a nearby supernova, or 5) An overlapping of two or more of those cataclysmic events over time. In any case, there was a severe depletion of oxygen during the dark ages of geology.
Extinction statistics for The Great Dying vary but are generally described as “96% of marine species and 70% of terrestrial species.” That apocalyptic event began at about 250 to 251 million years ago. All current life has descended exclusively from the 4% of species that survived The Great Dying. Trilobites, the dominant species at the time of the extinction, were obliterated forever. The same was true of almost all life: but…nooooo…not true for bacteria. They even thrived on methane while practically every other species choked to death during The Great Dying.
The Cambrian Period, also known as, The Cambrian Explosion.
The Cambrian Period began 530 to 525 million years ago and lasted 53 million years. Despite its four mass extinctions, the period is distinguished by its geologically brief but incredibly prolific burst of diverse lifeforms. In stark contrast to The Great Dying, the Cambrian Period is the centerpiece for life’s tenacity, resilience, and exponential diversity. The period is often referred to as The Time of Ancient Life, especially because of a special timeline within that period that gives the period its descriptive identity: The Cambrian Explosion! It was then that life got its act together.
Very Fast Forward
Human life made its debut about two million years ago. A few creationists and atheists continue tedious debates embodied by the expression, The Missing Link. The definition for that expression is: An intermediate evolutionary form between one animal species or group and its presumed ancestor [Meriam Webster, my favorite dictionary].
I don’t believe there is a missing link. I believe it has just been ‘overlooked’ or, more precisely, because intelligence cannot be found in the empty sculls of ancient fossils. The so-called ‘missing link’ is intelligent life.
Intelligence is aware of its self. It knows there is no phenomenon in the universe more enigmatic than its self. It thinks about thinking, as you and I do when we pause for contemplation. Even then, it’s not the content of our thoughts that’s necessarily enigmatic, but rather that the phenomenon of intelligent thought itself exists.
Bacteria activity is automatic, vegetative and insect life ‘talk’ to each other to warn, protect, and reproduce their kind, avian life communicates with vocal and flight patterns, marine fish communicate with movement and color displays, marine mammals communicate with vocal patterns, land mammals with an enormous range of communication patterns, including body language.
All those species existed long before humankind’s cue to enter earth’s parade of life. Our species’ distinction includes ─ but is not limited to ─ complex individuation, extensive habitat modification from pole to pole, complex language, science, art, and exponentially enhanced sense perception when it is combined with mind and technology that spans the microcosmic and macrocosmic worlds. A combination of those attributes has led us as a species to ponder the human species’ future, especially in terms of its survival.
On a personal note, I add my belief that mammals and primates brought love to the phenomenon of life. Even individuals of different species bond despite the instinctive hostility they continue to feel against the species to which their bonded individual companions naturally belong. And who is there that can rival the love between dogs and humans or monkeys and humans or apes and humans or horses and humans, and a host of other improbable companions!
As a species, humans are the only lifeform on earth that knows there is a universe. Many of us also know that all life on earth, even bacteria, can be extinguished at the blink of a geologic Age ─ or, far quicker than that.
Or worse, will there be a Slow Dying? This time, no survivors. No life at all. No possibility of life. A dead planet. Or, will we fumble into a global nuclear war? Will carbon dioxide and ocean acidification do to us what it did to the trilobites? Or, will we have been too slow to technologically eliminate the possibility of a massive world-ending asteroid impact? Will the earth become absolutely sterile because of a supernova gamma ray burst that will instantly transform earth into a radioactive killer?
None of the mass extinctions included in this article is as certain to extinguish all human life as is the species that will become extinct by its own hand. That killer is humanity itself. That mass extinction will kill all humans at a geological instant when the level of artificial intelligence hits 51%. Will a future geologic period be named: AI-51%, also known as, The Great Suicide?)