Till now Earth is the only home for life in the universe. Around 8.5 million species live on earth and among these only 1.3 million species have been identified. The journey of earth begins around 4.5 billion years ago, gravity pulled the rocks, asteroids
and space dust together form the giant planet which we called earth. When this planet was just formed, it was an ocean of lava and liquid rock and the temperature was around 12000C. Inside asteroids a strange salt like crystals
which we put in our French fries and minute droplets of water were present. These contain the vital ingredient for life. The asteroids and meteorites shower didn’t stop for billions of years, and soon created an ocean of water.
Molten lava erupted form the core for millions of years and created the crust and formed the land. Also many asteroids came with a very vital ingredient for life primitive protein which have amino acids. It’s impossible to know how and when but somehow these chemicals have come together to create life. And soon microscopic organisms came into existence, these single cell bacteria evolved for millions of years.
On the seabed, colonies of bacteria called ‘stromalolite’ were doing something which was responsible for the evolution of multi cellelular organisms. These stromalolite somehow transformed the energy of sunlight and carbon dioxide into oxygen in the process of photosynthesis. Oxygen then came to the atmosphere through the sea and then came all the plants and trees. Slowly over a period of million years the sea creatures came to land and started evolving into reptiles, then came the dinosaurs, apes and so on. These apes then evolved into the most intelligent species in the known universe, humans. And then the civilizations started and rest is the history as we all know .