6 Earth History Facts That Sound Like Sci-Fi
Earth: almost everyone reading this article calls it home (we see you, aliens). Earth is an awe-inspiring place, full of millions of plant and animal species, vastly diverse ecosystems, and countless mysteries about its ecological history and just what the heck is down at the bottom of the ocean. Sometimes, in all the primordial chaos, stories emerge that are way too wild to process, even for our weird-ass planet.
It Once Rained For Two Million Years
I’m going to say something I’m pretty sure no Cracked writer has said before: I’m a huge Star Wars fan. My favorite part of Star Wars is the laser swords, and as a guy who hosts a poetry podcast, I love that the movies rhyme. If I had one quibble, though, it’d be that every planet seems to have only one ecosystem. Like, Hoth is the ice planet, Tattoonie is the desert planet, Endor is literally described as a “forest moon” as soon as we hear about it. Why don’t these planets have diverse ecosystems? I mean, I know the answer is “easier storytelling,” but it’s kinda ridiculous to have a bunch of planets that are only one thing, right? (Note: come at me with some “in the extended universe” or “actually it’s canon” nonsense and I’m coming to your house to give you a wedgie.)
But apparently, I’m the stupid one! With his single-ecosystem world-building, George Lucas was tapping into something that happened a long, long time ago, on this very planet we inhabit. It kind of resembles Kamino! You know, where the Storm Troopers were cloned and conditioned to fight endless wars for an unsustainable empire. Can’t see anyone on Earth doing something like that, but still: the entirety of Earth was once covered in rain for two million years.
235 million years ago, at the beginning of the Triassic Period (the real-life prequel to that Sam Neil and Laura Dern rom-com), Earth was hot. All the continents were fused together into Pangea, the ocean was boiling, and not much was going on. Wildlife was limited to, like, a couple of lizards and a few plants. Rain was confined to coastlines because not enough water could evaporate fast enough for clouds to drift over the whole of Pangea. Then one day, like a Jerry Bruckheimer wet dream, some volcanoes in modern-day Alaska and British Columbia started erupting and didn’t stop for five million years (more on that later). That meant water evaporated quicker, so it started raining everywhere, and just kinda didn’t stop. For two million years.
It’s called the Carnian Pluvial Episode, and the resulting fossil and rock deposits have been blowing geologists' minds for years. See, Pangea was pretty monotonous -- dry and arid because rain clouds were mostly concentrated on coasts. So discovering evidence like river rocks and sediment from huge lakes when you’re expecting basic desert rock ... well, that raises a few eyebrows.
So what made this drier-than-an-AA-meeting planet start raining? Why, it’s that volcanic eruption I mentioned earlier! Those eruptions made things so humid that rain eventually spread to the center of the continent. Then the Earth decided to make up for lost time, I guess.
The rain led to an explosion of giant plants -- turns out water does to plants what a double-cheeseburger-a-day habit does to people. For their part, the reptiles who ate those plants evolved from tiny little lizards into the massive, Jeep-stomping dinosaurs. The rain eventually stopped, but not without changing the face of life on Earth: Conifers were here to stay, evolving into modern pine trees, and dinosaurs were here to stay until they, uh, weren’t. Hope that’s the last time we have to talk about extinction in this article.
The Hills Have Eyes (Literally)
Unless you live in an earthquake hotspot, you probably don’t think much about geologic formations in day-to-day life—mostly we just think about “the ground” or “those hills over there” or “this mountain we’re trying to climb.” But geology can lead to insane things, like the Earth developing a realistic-looking eye that can be seen from space.
The Richat Structure, also known as the Eye of Africa, is an incredibly symmetrical geologic dome with a veritable stew of different rock deposits. In less scientific terms, it looks like a big ol’ blue eye. Like if the land mass of Mauritania heard Frank Sinatra was hitting it big with the nickname “Ol’ Blue Eyes” and said “Yeah, okay I was doing it first.”
The sedimentary rock is about as old as you can get, dating back 2,500 million years to the Proterozoic Era (for all the young Earthers out there, think of this as “the third day”). It’s been a millennia-long journey for the Richat Structure to perfect its appearance. And it’s done so with the meticulousness of a Drag Race contestant getting ready to lip sync for their life.
The end result is a mesmerizing eye that seems to have been created entirely through natural processes like erosion, dissolution, and collapse. No human manipulation, no extraordinary events, just the planet grooming itself over millions of years. Planets: they’re vain, just like us! To be fair, this might be a case of our moron human brains trying to make patterns out of things, like “hey don’t that big rock look kinda like an eye?” But so what? It’s rad as hell.
Big Cats’ Fossils Are Hiding From Us
Big cats. Famously best friends to six-year-old boys, stars of our favorite Disney movies, and our most embarrassing obsession of quarantine. They’re some of the first animals we learn about as kids, because lions and tigers have easily distinguishable features, and they’re some of the last animals we ever see if we get lost on a hiking trip. They feel like cornerstone beasts, is what I’m saying, the kind of species the scientific community should really have a strong grasp on.
Well, hold that thought. Modern big cats evolved roughly 11 million years ago, and ... that’s about all we know, in terms of fossil records. We can reasonably guess that animals from the genus Panthera -- lions, leopards, jaguars, snow leopards, and tigers -- share a common ancestor, but we have no fossil evidence of what that ancestor might be. Were there different species between 11 million years ago and now? Who the hell knows! Not us, with our impossibly finite human brains.
Incomplete fossil records like this are known as a “ghost lineage,” which absolutely should be the title of a horror movie franchise, preferably one involving anthropologists getting eaten by undead big cats (dibs on writing that, by the way). But seriously, the first part of this article asserted that we know it rained for two million years long before humans were even a possibility, but we somehow don’t know bupkis about big cats? What gives?
Part of this fossil gap is due to cats being very territorial and having similar skeletal structures -- meaning fewer available fossils and tough time identifying what belongs to whom. The bones of a lion might look like the bones of a tiger might look like the bones of a snow leopard, making a scientist say “OH MY!” It’s difficult and frustrating to string those bones together in a way that holds up to scientific rigor, so we just kinda have to throw up our hands when it comes to big cat history.
“What about sabretooth cats??!," you might be shouting at your screen right now. Yes, sabertooth cats did exist some 42 million years ago. Some quick math *mumble-counts, draws imaginary equation in the air, gives up and uses calculator* tells us that that’s a full 31 million years before modern Panthera, which is a really long time. In fact, sabretooth cats are so far off from Panthera that calling them “cats” is something of a misnomer. They’re part of the same family, but just don’t quite have enough in common to talk about anything more than the weather at Thanksgiving dinner.
So where did today’s big cats come from? Scientists have basically answered with a shrug while mumbling “uh, maybe Africa, but probably the Himalayas.” But even that potential common ancestor, Panthera blytheae, lived about two million years before our modern big cats evolved. What fills in that gap? We don’t know. Ghosts, apparently. Ghost cats, that is. Two million years of big ol’ tigers, white sheets tossed over their bodies, eyeholes cut out, drifting over the fossil record.
Whales Used To Look Like Dogs And Isn’t That Nuts
I gotta be honest, this one is so mind-bending I can kinda see where the evolution-deniers are coming from. Like, you hear something like this, and you just kinda thousand-yard stare and contemplate the vastness of time.
Ok, picture a dog. Like a golden retriever, or a poodle, or a Snoopy. Got it? Ok, now picture a whale. Maybe a Free Willy, or a humpback, or a sperm. (Side note: how horny are whale-namers?) Got your dogs and whales in your head? Great. Now take a huge bong rip and picture this: they used to look the same.
To be clear: whales and dogs did not come from a common ancestor. HOWEVER! The earliest known ancestor of whales was Pakicetus, a land animal with carnivorous teeth. If you’re not well-versed in animal skeletons, you might wonder if Pakicetus was the earliest ancestor of a Greyhound. How did a land-dwelling, dog-looking bag of blasé evolve to become the sea-dwelling largest mammal on the planet?
Weirdly enough, “you are what you eat” is kinda true. Early Pakicetus drank both saltwater and freshwater, which led them to adopt a more aquatic lifestyle. All that swimming gets a lot easier if you have a built-in snorkel, so over time, their nostrils started to move back and become blowholes. Not to mention the easily accessible food -- plankton run away a lot less than mice or whatever, I’m assuming. Plus, life in water moves at a slower pace, encouraging animals to evolve to be bigger.
Eventually, those weird almost-greyhounds grew into whales. Out of basically dogs. What the hell.
The Death Of Native Americans Might Have Caused A Mini-Ice Age In Europe
In 1492, Columbus sailed the ocean blue, and most everything after that was a really bad choice. But how bad could genocide and reshaping a hemisphere be, really, on a global scale? Tragedy for the victims, yes, but could it really affect life on other continents?
Yes. The answer is yes. The “Little Ice Age,” a period of much cooler average temperatures than people were used to, lasted from roughly the 1300s to 1800s. When I say “much cooler temperatures,” I mean that even the Thames River in England would freeze over regularly. Considering the Thames is traditionally kept warm by industrial waste, year-round rain, and the bodies of hungry orphans, it’s definitely pretty tough to freeze over.
How do we know the genocide of Indigenous Americans caused the Little Ice Age? Sure, part of it was probably Earth’s natural climate cycles. But a huge factor was a massive drop in CO2 levels, with evidence reaching as far as Antarctic ice core samples. The drop in CO2 happens to spike around the 1500s-1600s, right around the time the Indigenous population was dying in droves. In an example of not-actually-all-that-satisfying karmic payback, Europe had to suffer some minor inconveniences for colonizing America.
See, the deaths of 90% of Indigenous Americans left 56 million hectares of land abandoned. Indigenous peoples had gotten really good at farming that land, and leaving it to grow wild led to a massive explosion of plant life. Those plants absorbed CO2 from the atmosphere and lowered the planet’s temperature. Remember those stupid “nature is healing” memes from the beginning of the COVID-19 lockdown, where people would take pictures of swans in Venice or whatever and it was evidence that Thanos was right? Turns out nature is affected by human activity and can heal itself in the absence of humans.
It’s a lesson in interconnectedness. European colonizers were obviously very bad to Indigenous Americans, but they were so bad that their actions reached all the way back home. It’s the butterfly effect, except with genocide and cross-continental famine.
The Earth Has Rebooted Itself Five Times
It’s very easy to read news about climate change and think the planet is being destroyed. And that’s true -- from a “life as we know it” perspective. Sure, animals are going extinct left and right, hurricanes are getting worse, “wildfire season” is becoming a thing in the American west, Miami is sinking before our eyes, the Maldives is holding climate conferences underwater because that’s what they’re going to be soon, there’s a goddamn trash island in the Pacific Ocean. Things kinda seem hopeless for humans (#Hopeless4Humans).
But let’s try some positive thinking: Earth isn’t being destroyed, it’s just becoming a new version of itself. One that can barely sustain life and cycles through a constant churn of natural disasters. You know how Venus is way too hot for us to even touch its atmosphere, and how we never talk about terraforming it despite it being our “sister” planet? Earth is Venus’s jealous little sibling, getting hand-me-down denim jackets while Venus buys cool leather jackets.
Anyway, life on Earth is slowly ending, but that’s not the first time this has happened. Earth has gone through five mass extinctions in its history, with barely anything surviving each time. Even the term “mass extinction” is pretty hard to comprehend, but it’s exactly what it sounds like: a vast majority of life being wiped out, then the remnants becoming something different. Think of it like Marvel’s Ultimates -- some old ideas remained, like multi-celled organisms, reptiles, and Captain America, but everything is clearly different now.
The earliest known mass extinction, the Ordovician-Silurian extinction event, killed 70% of all species. Then the Late Devonian extinction event duplicated those numbers. Then the Permian-Triassic event knocked off 96% of all species. Things evened out with the Triassic-Jurassic event killing somewhere between 70-75% (triggered by the five-million-year-long volcanic eruption I mentioned earlier). Finally, the Cretaceous-Paleogene event killed 75% of all species, paving the way for dinosaurs to become museum exhibits and humans to rule the world.
Each time, Earth’s terrain, climate, and supported life radically changed. It’s nuts. You could probably write a whole Star Trek series around the Enterprise finding an undiscovered planet while also hitting some sort of time-shifting wormhole and they interact with different eras of that planet at different times and it’d be insanely different week-to-week, and honestly? That planet could be Earth. That’s how shattering mass extinctions are.
Man, those extinction events sound brutal. Thank God they’re a thing of the past right? It’d sure suck if we were going through one right now, one that began in the early 20th century and is due almost entirely to human activity. That’d be awful. Just make sure if you google the word “Holocene,” you click on links to a Bon Iver song, not this thing that none of us will survive.
Chris Corlew formally requests entry into the Ghost Tiger Gang when the extinction hits. Until then, you can find him writing, podcasting, and making music. Or on Twitter, if you really wanna be at peace with extinction.