The history of life on earth is a very lengthy process. Earth formed about 4.6 billion years ago, and for a while, it was a junk of rock circling the Sun, suffering collisions with other junks of rock, generating unreal amounts of heat.
Eventually, the constant smashing slowed down slightly, and the Earth’s outer layer cooled. But the core of the planet remained hot. No oxygen was in the atmosphere, and volcanoes were firing off everywhere. But it was finally cool enough for some of the water in the atmosphere to turn from vapor into liquid. The evolution of life on earth timeline is a big list of evolution.
In them and the atmosphere, the first seas formed a soup of chemicals: nitrogen, nitrogen oxides, carbon dioxide, methane, ammonia, hydrogen, and hydrogen sulfide. The help of heat and lightning eventually created small organic molecules. In some way, life happened. The first life on earth probably wasn’t even life as we think of it. It was a collection of chemicals surrounded by a membrane because phospholipids spontaneously form bilayer membranes in water.
Over time, some chemicals inside these membranes developed into amino acids and RNA. The nucleic acid was probably the first genetic material. These collections of chemicals are trapped within membranes called protobionts. It likely began to grow and replicate until some crazy copying error gave way to DNA nucleotides.
It is a more stable repository for genetic information because it’s double-stranded, not single-stranded like RNA. So the first living things were prokaryotes, single-celled organisms with no nuclei. That was probably similar to the archaea found alive today in hydrothermal vents, sulfur hot-springs, and oil wells.
Evolution of life on earth timeline
Around a hundred and seventy million years after Earth’s formation, a similarly young planet known as Thea. Thea was demolished after the collision, and it merged with the earth. Therefore, the Earth’s mass increased, effectively reaching its current mass. The impact created a large ring of debris around the earth, forming into the moon.
After the ring’s dissolution, the moon became a glowing hot celestial body orbiting twenty-five thousand kilometers above the earth. The moon still had volcanoes, lava flows, and its magnetic field during this period. The tidal phenomenon between the Earth and the moon led to various changes.
- Firstly, the moon became tidally locked with the earth. It takes the moon as long to rotate around its axis as it revolves around the earth.
- Secondly, the moon gradually receded from the earth, cooled down, and became geologically inactive.
Currently, the moon’s average distance from the earth is 384,000 kilometers. Even today, it is receding from the earth 3.8 centimeters a year. As a result, it takes the moon increasingly more time to revolve around the earth. However, due to tidal locking, it takes to rotate around its axis is also increasing. The tidal phenomenon also affects the earth. The Earth’s rotation period is decreasing. It means the length of the Earth’s stay is growing slowly.
At a glance, the evolution of life on earth timeline.
1. The Origin of the Earth.
- 4.567 billion years ago: The formation of the Solar System.
- 4.56 billion years:ago: The formation of the Earth.
- 4.55 billion years ago: Giant impact.
2. Initiation of Plate Tectonics.
- 4.37-4.20 billion years ago: The formation of the atmosphere and ocean.
- 4.37-4.20 billion years ago: The initiation plate tectonics.
3. Birth of Proto-life.
- 4.10 billion years ago: The birth of the first proto-life.
4. The Initial Stage of Life.
- 4.37-4.20 billion years ago: The loss of the primordial continent and the generation of a solid geomagnetic field.
- 4.20 billion years ago: The emergence of sun-powered life.
- 4.10 billion tears ago: Mass extinction.
5. Second Stage of Evolution of Life.
- 2.90 billion years ago: The emergence of photosynthetic life.
- 2.70 billion years ago: Mantle overturn.
6. Third Stage of the Evolution of Life.
- 2.30 billion years ago: Mass extinction by snowball Earth.
- 2.10 billion years ago: From prokaryotes to eukaryotes.
7. The Dawn of the Cambrian Explosion.
- 1.90-0.80 billion tears ago: The Formation of a Supercontinent.
- 700-600 million years ago: The Sturtian Glaciation
- 700-600 million years ago: The Leaking Earth.
8. The Cambrian Explosion.
- 640 million years ago: The Origin of Multicellular Life. The Marinoan Glaciation.
- 580 million years ago: Appearance of Ediacaran Fauna. The Gaskiers Glaciation.
- 550 million years ago: Evolution Responds to Environmental Changes.
- 540 million years ago: The First Cambrian Organisms.
9. The Paleozoic Era.
- 600 million years ago: Expanding Habitats.
- 540 million years ago: The Co-evolution of Planets and Insects.
- 550-540 million years ago: The Evolution of Vertebrates.
- 260-250 million years ago: The Largest Mass extinction of the Phanerozoic Eon. Collision with a Dark nebula.
10. From the Mesozoic to the birth of human beings.
- Dispersion and amalgamation of continents and the evolution of life.
- The birth of primates.
11. The Humanozoic eon: the appearance of human beings and civilization.
Evolution into primates. The birth of human beings, the fourth animal category: the Humanozoic eon.
- 10000 years ago: The Agricultural Revolution.
- 5000 years ago: The Urban Revolution.
- 2400 years ago: The Religious Revolution.
- 300 years ago: The Industrial Revolution.
12. Future of the Earth.
- Challenges for Human society.
- Future of Human society.
- Future of the Earth.
- 200 million years later: Formation of the supercontinent.
- 400 million years later: Extinction of the C4 plants.
- 1 billion years later: Cessation of plate tectonics.
- 1.5 billion years later: Disappearance of the ocean.
- 4.5 billion years later: Collision between the Milky Way Galaxy and the Andromeda Galaxy.
- 8 billion years later: Annihilation of the Earth.
The history of earth timeline
Today, it can be tough to imagine that life on our planet was different. Let’s go back to the past 4 billion 600 million years ago when the earth didn’t exist. Only a newly formed proto Sun, a ring of gas dust, and an incredible sight.
4.5 billion years ago
About 4.5 billion years ago, the earth was formed. It was about as far from inhabitable as possible. The conditions on earth were hellish. Instead of the usual landscapes, there was a sea of fire from molten rock. There were radioactive elements all around. The surface temperature reached 4,700 degrees Celsius. That’s about 8500 degrees Fahrenheit. Instead of air, there was carbon dioxide, nitrogen, sulfur, and water vapor. Instead of solid land, magmatic oceans add to the constant bombardment from large asteroids.
After several million years resulting from a collision with Theia’s young planet, the moon was gradually formed. One day back then lasted about six hours. With such a short day having time for anything would be simply impossible. It’s good that the work date did exist yet.
4.1 billion years ago
The late heavy bombardment hit the earth with many asteroids from about 4.1 billion years ago to 3.8 billion years ago. Some scientists suggest that there were already oceans on earth at this time despite its high temperature. It was the asteroids that helped the planet gradually become covered with water. According to one theory, the asteroids carried a tiny amount of life-giving moisture and delivered it to earth. That’s how over billions of years ago, half of the water of the world’s ocean came to earth from space.
After the bombing ended about three billion eight hundred million years ago, the earth’s temperature slowly declined. But current life forms couldn’t survive on the planet’s surface because there was no oxygen in its atmosphere. Also, there was no ozone layer to block ultraviolet radiation. However, some fossils are about 3.5 billion years old. It means that life on Earth could have arisen much earlier than we used to think.
3.5 billion years ago
From 3.5 billion years ago, prokaryotes were all alone on Earth. The oxygen in the atmosphere suddenly shot up from none to 10% in a brief period. This oxygen was most likely produced by a brand new prokaryote called cyanobacteria. It had figured out how to make its food through photosynthesis. The more cyanobacteria there, the higher the atmospheric oxygen concentration became.
This “oxygen revolution” is spelled D-double-O-M for many prokaryotes that had evolved without oxygen. It was also one of the first real game changers for life on Earth. It was the first significant instance of living things bringing massive change to their environment.
It may be the earliest example of ecology at work. Cyanobacteria changed the atmosphere, judo-chopped the competition, and made way for the evolution of living things to take a new, specific direction.
3.2 billion – 2.8 billion years ago
From 3.2 billion to 2.8 billion years ago, almost the planet’s entire surface was occupied by a shallow ocean. The temperature ranged from 55 to 88 degrees Celsius and 131 to 190 Fahrenheit. However, microorganisms were already inhabiting this hot water. The land was only volcanic islands that were slowly growing over time. Imagine how hot it was! The days began to lengthen, and about 2.5 billion years ago, the first supercontinent Kenner land began to form.
2.1 billion years ago
Then, about 2.1 billion years ago, a new organism made its big debut: eukaryotes. These, as you know, are a big deal because they include all plants and animals. Eukaryotes probably evolved by endosymbiosis, where one prokaryote parasitized another prokaryote. The result was awesome for the host and the parasite/undigested prey. It formed a single-celled organism with organelles, specifically mitochondria, and plastids. It probably evolved from those eaten or parasitic prokaryotes.
1.5 billion years ago
Let’s fast forward a little 1.5 billion years ago. Earth days now last at least 16 hours. Though complex organisms still didn’t exist. But lithospheric plates continued moving, creating another supercontinent Rodinia after 400 million years.
650 million years ago
According to a famous theory, the earth was a snowball about 650 million years ago. This theory is called snowball earth. Scientists assume that everything was completely covered with ice and even the Equator was as cold as modern Antarctica.
It’s scary even to think about the temperature at the poles. But even under a thick layer of ice, the planet maintained a reasonably high temperature. No ice age can kill volcanoes and the carbon dioxide from their eruptions. It accumulated in the atmosphere and gradually melted the glaciers. This melting released a vast amount of oxygen which forever changed the planet.
541 million years ago
About 541 million years ago, the Cambrian explosion occurred, temperatures rising to 30 degrees Celsius or 86 Fahrenheit. A record concentration of oxygen caused many living organisms to emerge. The biological diversity was so impressive that some creatures even developed exoskeletons to protect themselves from being eaten by others. Researchers believe that almost all existing types of animals appeared during this period. The length of the day now reached 22 hours.
- About 450 million years ago, plants and arthropods began actively conquering the land.
- About 419 million years ago, the first insects appeared.
- About 300 million years ago, most of our planet was occupied by swamps.
The swamps of antiquity were not like modern ones. Some plants reached 30 meters in height, about a hundred feet, and giant insects flew everywhere. Be glad that our modern dragonfly’s huge ancestors didn’t survive to this day. Seriously that wouldn’t be the most pleasant
replacement for pigeons.
The planet’s geology has guided the evolution of life, and life has shaped the earth by existing. So earth’s geology during the arcane shaped what was probably the first form of life. In the warm oceans and carbon-rich atmosphere, biological molecules contained the necessary information to copy themselves and had the chemical ability to form from organic compounds. These became encapsulated in an oily membrane that kept them safe from the outside world.
- The first thing to resemble a living cell. Eventually, this early life transformed the atmosphere and climate.
Some scientists believe the earliest biological molecules were RNA, the molecule DNA. RNA is very similar to DNA, but it’s easier to form from simple components. It also stores genetic information the same way DNA does. But it can tangle itself into shapes that make it easier for chemical reactions to happen the way proteins do in our cells.
535 million years ago
Around 535 million years ago, the eukaryotes went berzerk. That’s known as the Cambrian Explosion, a super-major biological golden age when the diversity of all animal life on Earth exploded. Nobody’s entirely sure what started it, but suddenly life created innovations that the planet had never seen. Creatures used minerals and seawater to build skeletons and shells, some acquired weapons like claws, while others developed defensive plates.
The evolutionary arms race between predators and prey was underway. It heralded the dawn of the Phanerozoic Eon, the one we’re in now. The Earth spent the better part of two eons under the rule of many archaea, bacteria, and some soft-bodied worms until the Cambrian exploded. After the Cambrian, the party got so hot in the oceans by the Ordovician Period.
500 million years ago
About 500 million years ago, plants, animals, and fungi started colonizing land, probably a strategy for escaping predation. Now there were whole new ecosystems to explore and adapt to and create! About 365 million years ago, during the Devonian Period, tetrapods, four-legged vertebrates that probably evolved from lobe-finned fishes, showed up on land, and so did arthropods like insects and spiders.
We begin to see ecological systems we recognize today because organisms were changing their environments by consuming oxygen in the atmosphere and releasing carbon dioxide.
The Carboniferous Period, which extended from 359 to 299 million years ago, was when the plants went nuts. The forests were so dense and widespread that they made fossil fuels. All the coal and oil were made over about 60 million years. This time, it was the plants that had changed both the climate and the geology of Earth.
These forests cranked out so much oxygen that the atmosphere contained around 35% rather than today’s, like, 21%. This oxygen started cooling the planet because there wasn’t enough carbon dioxide to maintain the balmy temperatures that the vast carboniferous jungles needed to survive. So, the whole system crashed. All the carbon from these forests sunk into swamps and eventually locked in rocks.
252 million years ago
About 252 million years ago, the Permian Triassic extinction event destroyed 96% of marine species and 73% of terrestrial vertebrate species. Most likely, numerous eruptions became the cause of extinction. The air was filled with ash and carbon dioxide.
There was little sunlight, plus lava was flowing everywhere. Anyone could die in this environment. Dinosaurs then arrived to replace the destroyed species, but enormous dinosaurs divided the planet among themselves. The continents also moved.
175 million years ago
About 175 million years ago, Pangaea began breaking up the Atlantic, and other oceans appeared. The world started taking on the current form that we see today. You could find the first pine trees praying mantises, and bees at this time.
So by the Jurassic Period, about 199 to 145 million years ago, huge herbivorous dinosaurs were roaming the Earth; smaller, mean-as-crap carnivorous dinos were stalking the herbivores. The oceans were full of giant squid and ichthyosaurs and long-necked plesiosaurs. The air was full of pterosaurs and the first birds. There were mammals! Small ones, but they were all over the place. It wasn’t our time to shine.
100 million years ago
For instance, about 100 million years ago, angiosperms, or flowering plants, first appeared, and they did well. Mainly since flying insects evolved with them, providing an excellent vehicle for reproduction. It is a great example of another ecological principle, co-evolution. But dinosaurs liked to eat the old-fashioned gymnosperms. With the dinos out of the picture, mammals and birds were free to take over. It is where flora and fauna on Planet Earth started looking a lot more like they do today.
Since then, climate fluctuations, extinction events, and the evolution of many animals and plants, including humans. Oddly enough, on a geological scale, that brings us to today. Ecology is all about action and reaction: an asteroid hits, and much stuff happens because of it.
50 million years ago
About 50 million years ago, the power over the planet was then passed on to mammals. Without dinosaurs, they began feeling freedom, actively spreading around the planet and evolving with all their might. Meanwhile, the length of the day had reached almost 24 hours, and the temperature stable remained near the 24 degrees Celsius mark. That’s about 75 Fahrenheit.
8 – 4 million years ago
Scientists say a critical split occurred about 8-4 million years ago. The ancestors of modern Apes began separating from our ancestors. Each was heading down its evolutionary path.
About 4 million years ago, the planet’s climate changed. It didn’t happen right away. But the climate turned part of the dense forest into a savanna. According to one theory, this is what made our distant ancestors climb down from the trees, stand up straight and start looking for food. They were not the only particular species that began fighting for survival. Many tried to adapt to the changes, but in the end, only humans succeeded to the degree that they went on to invent tools.
1.4 million years ago
About 1.4 million years ago, Homo erectus began to colonize Eurasia. About 790 thousand years ago, they already knew how to use fire. What the earth’s population was precise during this period is rather difficult to calculate. The population census at that time wasn’t perfect. Then, about three hundred thousand years ago, Homo sapiens appeared the reasoning human. They appeared and began to populate the entire earth so actively.
130 – 40 thousand years ago
If about 130 thousand years ago, the number of our ancestors ranged from between 100 to 300 thousand individuals. Then already 40 thousand years ago, the expansion of reasoning human beings covered almost the entire planet. Today the world’s population is 7.8 billion people and continues to grow. However, the earth is changing along with its people. So who knows what turn of history awaits us in the future.
Life is a thing that happens. It’s still happening today and will evolve and continue as long as there’s a place it can happen. Darwin didn’t know when he wondered about that warm little pond, full of chemicals, giving rise to life. But his theory of how things change and adapt turned out to be powerful. It encompasses life, not in its endless forms but also in its first ones.
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Sources:
“Age of the Earth.” U.S. Geological Survey.
Dalrymple, G. Brent. “The age of the Earth in the twentieth century: a problem (mostly) solved.” Special Publications, Geological Society of London.
Manhesa, Claude J.; “Lead isotope study of basic-ultrabasic layered complexes: Speculations about the age of the earth and primitive mantle characteristics.” Earth and Planetary Science Letters. 47 (3): 370–382.
Schopf, J. William; Kudryavtsev, “Evidence of Archean life: Stromatolites and microfossils.” Precambrian Research.
Borenstein, Seth. “Oldest fossil found: Meet your microbial mom.”
Pearlman, Jonathan. “Oldest signs of life on Earth found.”
