Your ancestors are hydrogen atoms. Overtime, these atoms interacted, exploded, melted, decayed; and then, they formed stars and planets and chemically stable precursors of life. Soon enough, minds and things that bite were in the picture.
In just under 7 minutes, the late astrophysicist Carl Sagan shows us the trajectory of life and evolution. His story begins 9ish billion years after the birth of the universe, so let’s rewind as far back as possible. Life’s precursor began almost 14 billion years ago, when a lump of infinitely hot and dense plasma erupted to become everything knowable. In under a billionth of a billionth of a millisecond, there was light.
This eruption of unimaginable intensity formed stars, and the stars began to cool over billions of years. Some stars collapsed, enriching space with a handful of elements from which every natural element would form. It is from this chemistry kit that every single organism ever to inhabit earth would develop. It was the stars that died for us. Many of the stars’ remnants would later form rocks, and some stars and rocks would form solar systems. Others would remain forever in the distant horizon.
Earth was one of these rocks. Life began with a soup of lifeless molecules. On the first day, random molecules bumped into each other — they either repelled, remained neutral, or attracted one another. From the first day on, the experiment that would later be called “Creation” had an infinite amount of time to form thermodynamically favorable interactions. These interactions gave rise to stable bilayers, from which all lifeforms would evolve. At some point, these bilayers housed the precursors of cellular machinery — again, through trillions of improbable, but not impossible, interactions. (Wonderful things can happen given a deadline of “When the Universe collapses”). And so, simplicity became complexity little by little, step by step, over billions of years and trillions of interactions.
Over time these cells, these free-floating bubbles of chemistry, became self-replicating. Some remained simple but efficient microorganisms. Others adapted to changing environments and became even more complex. Meanwhile, gills and fins, feet and lungs, brains and ideas came into the picture. Mutations and competition for a finite number of resources would lead to evolution by natural selection — some mutations were better at surviving than others, and the fittest tended to survive in a particular environment. A lucky few of these lifeforms would become forever suspended in time in the form of fossils. Humans came along for the ride about 3.5 billion years after Day 1.
This is how the inanimate became animate, how the oil of lifelessness and the water of life would separate from a common soup of plasma. Sagan’s video shows the cross-section of history on which life has happened. Today, we need only to turn to museums to see the hundreds of millions of fossils documenting the transitions in life’s remarkable history. We can also turn to our genes to see the modern micro-fossils that are preserved across all species. We can even crank up the microscope some more to see the nano-fossils in the form of hydrogen and carbon atoms. Just as the genes that make up a human are reflected in the genes that make up every other organism, the atoms that make up the human body are reflected in the atoms that make up the stars. We are what happens when the universe becomes mindful of itself.
On a side note, life’s grandeur is rivaled in magnitude only by the hilarity (and appropriateness) of this clip: