The Earth is over 4.5 billion years old – that’s way longer than life has existed on the gorgeous globe. But what would happen if all of Earth’s existence was squeezed into a single 24-hour period?
Well, the day would start off incredibly dull. There wouldn’t even be life until about 4 in the morning – that’s when things start to happen, but you would be hard pressed to call it interesting. From 4 in the morning until 1 in the afternoon, there is nothing except unicellular organisms. After lunch, things finally start to get interesting.
What If Earth’s Age Was Just 1 Day?
Given how long Earth has been around, humans have only existed for a mind-blowingly brief period of time. Here’s a closer look at just how long it took for humans to start roaming the planet – and everything we missed by coming late to the party.
1. Young Earth collides with another planet called Theia around midnight
After the collision with our planet, the outer rocky shell both planets were blasted into a debris disk that now orbits our world – though it has changed a lot since then. From this odd little mess of debris, we got our only moon. Scientists have theorized that most of the material from Theia became part of the moon. Any iron core of Theia was completely obliterated by the core of the Earth.
The positions of the Earth’s magnetic poles are now reversed – as they do once every 250,000 years. That’s right, the North and South Poles constantly switch their positions – at least magnetically!
When the Earth’s life is crunched into just 24 hours, this change happens every 12 seconds!
On top of that, the continents are merging into one supercontinent at a rate of about an inch per year. That’s about once every 400 million years, but in our new crunched timeline, the continents are constantly crashing and splitting into new shapes constantly. Kind of like an amoeba, which brings us to the next big event.
2. The atmosphere is changing, resulting in the appearance of the first organisms
From midnight to half past four in the morning there really hasn’t been much to see, just the earth and its atmosphere changing. It’s kind of like watching grass grow.
Then anyone paying attention will see something happening in the water – the first unicellular organisms start wiggling around 5:30 in the morning. Our planet’s atmosphere is thick with methane, and these teeny tiny creatures are looking for a way to move out of the water. Unfortunately, that methane makes life on land pretty much a non-start. At least at first.
Overall, the methane haze persisted for about a million years, and once enough hydrogen was removed from the atmosphere, the appropriate chemical conditions prevailed. This was the start of fortuitous the oxygen boom allowing multicellular life to evolve.
3. The first viruses appear
It is 8 in the morning and the first viruses emerge. They will have a long time to rule the planet, though how they survived was likely very different since there weren’t many other organisms for them to infect.
At 11 in the morning, the microorganisms involved in photosynthesis have soaked up enough sunlight for the previous 6 hours. The byproduct they release into the atmosphere continues to boost the amount of Earth’s precious oxygen!
Buckle up because this is where things start rolling as life begins to evolve after it can survive outside of the water.
4. The first ice age begins
At 11:35, the temperature plummets to sub-zero, and we can see the first snowball forming. Even the water begins to solidify into a layer of ice.
Don’t panic! Everything will have melted again by lunch time.
5. The beginning of plants and animals
Around 1 in the afternoon, we see some cells with internal organs, but those organs aren’t quite functional. These cells will one day be the mushrooms and other small life forms – or so we think of them today – but for their time, they were pretty big as far as life went. Eventually, they will be the beautiful flora and fauna that make Earth so beautiful and unique in the solar system.
It might seem that these cells are taking an eternity to go from very simple to incredibly complicated, but, well, they are evolving as fast as they can. Crunched down into a single day, it takes them no time at all.
6. Sponges and placozoa appear
At 7:20 in the evening, we FINALLY have something familiar: sponges.
It’s 7:45 and another creature is about to enter the world – Placozoa! Admittedly, those are far less well-known, but just as important. Since it’s only 1 millimeter long, you’ll need a microscope to see it.
However, you should keep an eye on it because it’s going to have a very important role in life as we know it.
7. The second ice age strikes
It’s 7:55 in the evening, and the Earth is once again completely frozen. Placozoa decided this wasn’t great for their microscopic existence, so they started to rapidly evolve.
At last, things are moving!
Now that the ozone layer has formed, we can take off our sun-protective clothing around 8:30 in the evening. It takes only two minutes until the ocean is covered with vegetation.
8. Life in the ocean starts developing
At 8:45 pm, the oceans are teeming with life. Jellyfish can be spotted among the corals. We do not have full-fledged starfish yet, but you won’t have to wait much longer for these stars of the ocean.
At 8:52 seconds, we can see footprints on the seafloor. This indicates that the sea hatchlings have started to crawl. They aren’t quite the same as the ones we have today, but their great-great-great-great ancestors.
After another 4 minutes, we finally have an animal with a spine! If only it could have happened in 4 minutes instead of 15 million years. And still most of the party is in the water.
9. Moving from the water to land
It’s 9:10 pm, the sun has set, and the sea creatures are living it up as they find out just how far is too far with evolution. It also means that life is pretty crowded and dangerous down there, making the land have a certain type of appeal. Interested in exploring a few dip their fins or claws out of the water to see if the unused real estate might be worth exploring.
The answer is a resounding yes. New kinds of plants and animals appear, invading every corner of the world at breakneck speed.
In less than half an hour, the planet’s dry parts go from wasteland to wonderland. The number of forests and green spaces make for a gorgeous change.
We even get a bit of mobile life moving around the place, though many of them take to the air. Sorry, no not bird – bugs. They had to start somewhere too, but during this time at least they weren’t everywhere yet.
Interesting to be sure, but let’s quickly move along to something a bit less creepy.
10. 4-legged creatures make their debut on land
Around 9:45, some enterprising 4 legged animals enter the shallow water, then take a chance on land. These 4-legged animals are called tetrapods, but by 10:10, they’ve evolved into two new animals – the sauropsids and the synapsids.
The sauropsids eventually turn into reptiles, birds, and dinosaurs. Clearly this is the exciting evolutionary path because who doesn’t love dinosaurs?
Synapsids are the ones we’ve been waiting for though. They start off looking similar to reptiles, but they are the start of a completely new kind of animal – mammals. Yep. This is our earliest ancestor, but thankfully we didn’t get our looks from them.
Two minutes after starting to roam the lands and these animals are taking over everything – but this animal boom won’t last long.
11. A mass extinction wipes out so much evolutionary work
All of those animals don’t even get a full hour to enjoy their time in the sun. By 10:30, it gets hard to find any life on Earth as a mass extinction wipes out most of the animals roaming the lands at that time.
Scientists believe that no more than 5% of the animals made it out alive, though they don’t have an exact explanation for what caused so much destruction. The most likely guesses are that it was either a particularly deadly volcano or meteor that messed up the Earth’s delicate atmosphere.
Remember how long it took for the air to be safe for animal life? It seems a safe bet that disrupting it would have some pretty serious consequences to animal life.
12. We have dinosaurs!
It’s well past most people’s bedtime, but if you made it to 10:34 at night, you are in for a treat. There are dinosaurs stopping around, almost as if nothing at all happened.
The first of these massive creatures was the Nyasasaurus, though it wasn’t enormous. There are still debates raging among scientists about whether it was actually a dinosaur or just a stepping stone to the large beast, but either way, they are definitely going down the right path.
As you may expect, there are things lurking out in the night, and this time, there is a second wave of mass extinction around 10:45. Talk about having a rough time of it – two mass extinctions in under an hour.
While a lot of animals died off, the dinosaurs took the opportunity to change and spread all over the world. And those changes are subtle – at 10:50, the T-rex is showing off its well-honed predatory instincts and terrifying the other animals that were unfortunate enough to share the land with them.
13. The first birds take flight in Europe
Take a deep breath and stretch as you get ready to head inside. As you stretch toward the sky you notice there are some shapes up there that look very familiar – but only if you are in Europe. Birds have finally made their appearance, and boy did they know how to survive.
Looking a bit closer, it’s clear they aren’t the birds we know today, but an evolutionary step between dinosaurs and modern birds. They’ve got something like the head of a smaller dinosaur, but wings and the ability to fly. Quite a terrifying thought if they had remained large – probably for the best that they generally kept shrinking in size over the next hour.
14. Nature takes an interesting path in Southeastern Asia and then Australia
At 11:03, you start to notice some very interesting choices by evolution in Southeastern Asia. Kangaroos and other marsupials are a very interesting take on what mammals could be. The kangaroo was the first of these intriguing animals, making it far easier to bear children by letting them grow up in a pouch instead of being born after fully developing.
Remember that the continents are constantly colliding and separating? That’s probably how they ended up in Australia. They actually made it to North America within 15 minutes of them popping up on the planet.
15. Flowers bloom and mammals continue to evolve
It only takes a minute before the Earth starts to look more colorful as plants realize that flowers make it easier to make more plants. Flowers are newer than kangaroos. That’s a bit of a mind-bender.
When 11:15 rolls around, mammals begin to take four different evolutionary paths. Hoofed mammals start to clop around on their four legs looking majestic and sturdy. This particular group will take a very interesting turn, resulting in whales and bats down the line. It’s hard to think of animals less like a hooved animal than whales and bats, but evolution doesn’t seem to mind a good dose of irony.
The next group will be familiar – it’s our ancestral line! No, we haven’t quite made it yet, but there are a number of types of primates wandering the continents. At this hour, humans can’t be too far behind right?
There isn’t much that is obviously similar with the next group, which includes elephants and manatees. Apart from both being large, gray, and vegetarian, there isn’t much that is obviously similar, but their genetics say otherwise.
The last group is largely populated with animals that tend to focus on eating bugs. These mammals come with long snouts, like aardvarks, armadillos, and anteaters. Their timing certainly wasn’t a fluke either as ants are only five minutes older than them, and the ant population is out of control.
16. Dinosaurs rule!
It’s a good thing that humans weren’t around at this time because we couldn’t have handled the reign of the dinosaur. Exponentially bigger than Earth’s largest land animal, the elephant, these creatures knew they were in charge.
Imagine if you were to look out your window on the 7th floor of your building to see a Argentinosaurus staring back at you. This wouldn’t have been a problem for them, but it could have been terrifying for you.
17. An asteroid starts the third mass extinction
This time, there is far less speculation about what happened. At 11:26, an enormous asteroid hit Earth, creating a massive dust cloud that interferes with the atmosphere. Scientists are pretty certain about this because of markings left behind in the Earth’s sediment.
When the dust settled, the dinosaur reign was decidedly over. Replacing these massive creatures were mammals. And this new creature would go on to start their own reign over the planet.
Just a half hour before midnight, and the primates have started down their own interesting evolutionary path, splitting off into two distinctive groups.
18. Humans appear
The day’s coming to an end, we are just 2 minutes from midnight, and still, there are no humans roaming the planet.
However, something promising is happening. Some interesting animals start to appear … It’s chimpanzees and bonobos! But that is still a long way from humans, right?
It only takes these animals 15 seconds before they start walking upright, evolving into the hominin species.
It will take until 11:59:23 before the first human is walking the lands in Africa. That’s only a little over 30 seconds before midnight!
Though they aren’t able to use tools or communicate like we do – no I mean talking, not technology – they definitely look a lot like us.
Talk about a last-minute save!
It will take them until 11:59:58 – yes, just 2 seconds before midnight – before they start talking and using tools. That was just 100,000 years ago, which is next to nothing compared to how long the Earth’s been around.
All of human history as we know it was less than a second of Earth’s 24-hour history. Yet we’ve managed to squeeze an awful lot into that tiny timeframe, including being the first known animal to leave the planet. But it’s such a great place, who wants to leave for good?