Have you ever thought, how we have ended up shaping this world?
Some of the major events were huge yet impacted only a continent or two. Others literally touched every culture and brought them into a whole new way of thinking and growing with the Earth.
Earth History
Our planet Earth has existed for 4 t billion years and has been a busy few eons. Here we are with the 8 biggest turning points that bring milestones in Earth history. From evolution to devastating asteroid impacts and mass extinction, these were some of the major turning points that have shaped our world.
8 Biggest Turning Points In The Earth History
1. The First Mass Extinction
The Ordovician period (460-430 millions years ago) was a time when life flourished. But towards its end, the world cooled dramatically and ice sheets spread from the poles. The ensuing ice age is called the Andean Saharan because the evidence of it comes from the Andes mountains and Sahara desert. This deep freeze still counts as the second worst mass extinction on record the Ordovician Silurian. In these 85% of marine species were wiped out. Most life was still confined to the sea and after that fish became much more common.
2. The SuperContinent
For the last time, all Earth’s continents came together to form one giant supercontinent. Known as Panagea, it was surrounded by a world spanning ocean called Panthalassa. It lasted until 175 millions year ago when it began to tear itself apart over 10 millions of years. It’s shattered remnants became the familiar modern continents.
3. The Permian Extinction
At the time (252 millions years ago), when reptiles were flourishing, life on earth faced one the greatest challenge. The Permian extinction was the worst mass extinction in the planet’s history, obliterating upto 96% of marine species and a similar number of land animals. Till date no one knows the cause of such a massive volcanic eruption creating what is now the Siberian Trans have been blamed. In the aftermath, the first dinosaur evolved.
4. The First Mammals
At the same time (220 millions year ago) that the dinosaurs were spreading and diversifying the first mammals evolved. Their ancestors were reptiles called cynodonts whose faces looked a little like those of dogs and may have fur or whiskers. The early mammals such as Morganucodon were small and shrew-like to be nocturnal nature. This may have spurred them to evolve warm bloodedness – The ability to keep their body temperature constant.
5. The Triassic Extinction (201 millions year ago)
The dinosaurs were flourishing on land and in the sea giant reptiles called ichthyosaurs had become the tip predators. This caused another disaster namely the Triassic extinction, it killed off around 80% of species. In the aftermath the dinosaurs became the dominant land animals and eventually reached titanic sizes. The dinosaurs became the dominant land animals and reached upto enormous weight of 59 pounds.
6. Death of Dinosaurs
65 millions years ago a huge chunk of rock from outer space smashed into what is now Mexico. This explosion was devastating but the longer term effects were worse. Dust was thrown into the upper atmosphere and blocked out sunlight and in the ensuing cold and darkness. The earth suffered it’s fifth and last mass extinction. The dinosaurs were the most famous casualties but pterosaurs and giant marine reptiles were also wiped out.
7. The Starting Of Humanity
Around 25 million year ago, the first apes appeared in Africa. The group split into the ancestors of modern humans and the ancestors of modern apes. It’s difficult to say exactly when but thanks to modern genetics and host of fossil discoveries. It’s a rough idea that the oldest known hominid was Sahelanthropus tchadensis which lived about 7 millions year ago.
8. The Human Race
Homosapiens only existed for a fifth of a million years and are known to be as youngest. In that time we have expanded from our African birthplace to reach every continent and even outer space. Our activities have precipitated the sixth mass extinction and unleashed the fastest episode of climate change in Earth’s history. Yet we are also the only species that has ever managed to piece together the history of Earth.
These are some of major incidents in the earth history which have shaped the earth in present condition.
