Man has always been fascinated by the possibility of life on other planets. We love shows like Star Trek because it fills the void in our knowledge about alien life forms. But many scientists and astronauts believe that we must first look at the planet Earth for any in-depth study about extraterrestrial life.
How Earth evolved can give us clues as to what kind of life form is out there - if any - and how they also came to be. Earth is home to hundreds of thousands of plant, animal and even microbiological species with one thing in common: Their need for energy. Yep. the main reason for almost everything biological - from bacteria to humans - existing on Earth - is to EAT to gain energy.
You'll find the smallest and most abundant organisms at the most basic level of life: bacteria and single-celled microbes. Bacteria can live anywhere - from the deserts, jungles, inside and outside human beings and even on frozen mountains where nothing else can survive - because they eat anything. If there is energy stored in any object, bacteria will find a way to consume it. Case in point: Sunken battleships from World War 2 currently on the ocean floor are covered with iron-eating bacteria.
In another part of the planet, the Hang Son Doong cave complex in Vietnam hardly gets any light, yet the cave floor is full of lush plants, taking whatever energy they can get their hands on. Moving on to more complex organisms, camels will probably look like an alien if you've never seen one before. But just like the bacteria and the cave plants, camels are built to survive their living conditions. They have wide teeth to help with their diet and a fat-filled hump that conserves energy for a very long period.
The life forms found on Earth have adapted to suit their surroundings. Maybe this is also happening on other planets. But then, how did life begin on Earth? For billions of years, microbes lived side by side, eating everything - including other microbes, until that point in time where one microbe consumed another one but did not digest it. The two merged and transformed into the mitochondria - also known as the powerhouse of the cell.
This changed history. These simple organisms changed into something a little bit more complex and, while bonded together, began to use oxygen for energy. Another two or three billion years later, they evolved into human beings.
There were so many different ways that Earth could have developed, but the way it ultimately did, has made the planet and everyone on it exactly how we are today. As for extraterrestrial life forms, it is unlikely that another planet will come to be in the same way we did.
So if we do meet any aliens out there, they will probably be unusual. No, we will not be bumping into any biped Vulcans like Mr .Spock but probably into simple life forms like bacteria and other single-celled microbes.
Directed by: Nat Sharman