The 22nd of May is celebrated around the world as International Day for Biodiversity -- a day to celebrate the existence of that little sparrow on the tree, the colourful caterpillar on the leaf, the gigantic Blue whale in the ocean and the majestic elephant in our forests. It is a day to appreciate that our planet is blessed with so many life forms and understand each one’s role in maintaining this ecosystem. A small imbalance in this ecosystem can spell doom for all of us. On this day, here is a brief look at how we have understood biodiversity throughout our history and some important takeaways in the process.