If we want to know where humanity is headed, or even why we are here, perhaps the best place to start looking for the answers is in the deep past. These prehistoric foundations set the stage for our species. More importantly, it lets us calculate our current trajectory. This is where we will begin our story, within the cataclysmic stirrings of Earth's primordial beginnings.
Billions of years ago our planet was an inhospitable place, covered in a great sea of molten rock. The atmosphere was thin & unstable, being stripped away by solar winds. Over time it became more dense. An atmosphere of helium & hydrogen shifted to one of carbon dioxide, nitrogen and water vapor. Torrential rains fell in global electrical storms, forming the oceans, and cooling Earth's tectonic crust.
The Spark of Life
Within this primordial soup were the building blocks of life, heated and electrified as in some strange science experiment. The chemistry became more complex, as molecules formed into compounds, compounds into amino acids, and amino acids into proteins. And somehow from this mix, a protein developed that had the ability to self-replicate. It was a precursor to DNA, the molecule of life.
While science may postulate various hypotheses on how this process was initiated, it can't yet claim to have all the answers. Throughout history we've been filling the holes in our understanding, and this continues today. If in the meantime the Church wants to assert that some divine power was responsible for this first spark of life, then let them do so. As with other unexplained phenomena, it can appear as though the only solution is magical or supernatural, until we discover the mechanism by which it operates, and then it reveals itself as another beautiful aspect of an omnipresent, natural law. And yet knowing the process by which the universe functions should in no way make it any less sacred, or any less worthy of reverence. What science can offer though is some help in retelling the story, such as the sequence of events that followed this emergence of life.
It was a world of single-celled life. To survive, microscopic organisms absorbed nutrients from their immediate environment, and then replicated. But the amount of energy that could be extracted from this surrounding biochemical energy was limited. The foundational code within their DNA was still primitive. Over time it would be refined through natural selection, the incremental experimentation of slight mutations. It was a painstakingly slow process involving billions of replications. Incrementally the cells that had a more successful formula would dominate their environments, passing their more advanced DNA to successive generations.
Photosynthesis Shifts the Atmosphere
Life existed on this basic level for a billion years with little change. But then a key adaptation occurred that would forever change the future of the planet. Some of the proteins within these simple cells developed a reaction to light, using that increased energy to boost their metabolisms. Eventually these cells evolved into a kind of blue-green algae. It had the ability to directly capture the energy of the Sun via photosynthesis, expelling oxygen as a byproduct.
This evolutionary leap triggered a major shift in the atmosphere, the Oxygen Catastrophe, where most preexisting planetary life was destroyed. It wouldn't be the last time one of Earth's species fundamentally transformed the planet. But it was this simple algae that began the atmosphere's transition to the air we breathe today. The forests and oceans continue to inhale CO2, and exhale the oxygen that we so depend upon for life. It is this biological system that has allowed Earth's atmosphere to reach an oxygen rich balance. This atmospheric shift laid the foundation for the evolution of complex forms of life.
So breathe deep. Let the air fill your lungs. There's a reason why meditation and martial arts traditions place such importance upon the breath. Within the west the word "Spirit" was derived from the latin term for breath. It's oxygen that your red blood cells are pumping through your veins. This circulatory system allows you to move and to think. Only because of this important molecular ingredient can your body convert food into energy. Your exhale then removes the waste product of carbon as CO2. And so the whole process starts anew, a closed-loop, in symbiosis with Earth's photosynthetic life.