Why life as we know formed?

Here is an image of Trex skeleton from museum in helsinki,

Countless species have evolved and perished on this earth, all using the same DNA code to encode structure of the entire organism, meanwhile slowly changing through various process through natural selection and random mutations. Also notice how big the jaw has become for Trex gene line to survive in the wild at those times, it is as if only those dinosaurs made who had their jaws bigger and it kept on getting selected, ultimately when the meteor struck. Imagine the force and pain feelings of head of a Trex.
Even so why the first cellular organisms formed, its as if the flow of the universe through forces bought a cell together from its constituents, and before its constituents together from existent stuff. Since we perceive in our brains, was some kind of weaker perceptive existence also existed without the brain like forms that evolved later. Countless iterations have taken place for it to develop in various forms, and constructed us as we are today. Its as if universe runs by itself, and so anywhere in the universe similar life forms would have formed.