You are the result of an unbroken chain of organisms that were successful in surviving long enough to reproduce. An unbroken chain. Do you realize how unlikely this is? Over the billions of years that life has evolved on this planet, billions, there is a perfect unbroken line between that first speck of life, whatever it may have been, and you. I think that at the heart of this fact lies the power that evolution can have in informing your individual existence.
The vast majority of lineages, let's call them species, that have ever lived are now extinct. Not only that; the vast majority of species that will ever live will go extinct. In a way, the most natural of all organisms is a dinosaur, in a metaphorical sense of course, since the most natural thing for any species to do is to die out. We have a mass of unquestionable evidence that enables us to say that this is true. If it were not, there would be no evolution.
Yet here you are! As unlikely as you are, you are here nonetheless. This is a wonderful and awe-inspiring thought, and one that fills us with life-affirming gratitude. After all, the privilege of living is to be preferred over the possibility of never having existed at all. But before your own unlikelihood makes you feel uniquely special (or specially unique) or even that you are here purposefully, consider this question -- where else would you be?
You are the result of a perfect unbroken chain of organisms that through an evolutionary history extends back to the origin of life itself, that's true, but where else would you be to be able to ask yourself why this is?
Nowhere else but here.