The Great Chain

The Great Chain

Thursday, August 26, 2010

Why I Don't Believe Part 3 - The Origins of Life

Ancient peoples not only puzzled over how the Cosmos and our Planet came to be, but also wondered how it is that WE came to be, how life came to exist on this tiny blue planet of ours. The importance and divisibility of this question is best illustrated by the fact that even the most ancient peoples tended to separate creation from life. In the Bible, for example, God first creates light and darkness. The Lord then creates the sky and separates it from the waters. He follows that by the creation of the earth and the creation of plants. The sun, moon and stars follow. Then He creates the creatures of the seas, the creatures of the land, and finally man. Even the earliest humans, with no scientific knowledge or understanding whatsoever, intuitively grasped that the creation of the cosmos and the existence of life were two separate phenomena, likely stemming from the fact that simply answering the question ‘Where did everything come from?’ did not necessarily answer the more specific question of ‘Where did WE come from?’

In answering that second question, ancient peoples again turned to mythology. One of the most amusing and enduring traits of humankind is that when we don’t understanding something, we make something up. We tell stories utilizing things we do understand. Which is how we end up with the creation myths that have endured to this day.

The Atheist delights in the fact that we can accurately describe the formation of our world. We can literally describe with stunning clarity the processes by which our planet was formed! We UNDERSTAND! And the story of the birth of our world does not require any magic or any deity? Indeed, the story of the birth of our world is even more amazing, profound and powerful because of the wondrous serendipity by which it arose. Even more profound than the physical formation of our world is the rise of life. The evolution of life on this planet is cheapened if it is reduced to some manner of divine laboratory experience. Because the truth about how our species arose, the truth about how we came to exist on this planet is one of the most elegant, beautiful and meaningful events this planet has ever experienced. The power and beauty of the story of life deserves to be told and understood in all of its glory, not cheapened with fevered tales of magic clay and stolen ribs.

The reality is that our tiny planet was formed 4.5 billion years ago from the remnants of a star that died tens of thousands, possibly millions of years earlier. As clouds of gas were excited and compressed, gravitational attraction caused the gas and dust to coalesce. The vast majority of the mass in our immediate vicinity gathered in the center of a vast accretion disc, forming our sun. The tiny fraction of mass that was not pulled into the center by the inexorable tide of gravity formed a thin disc of gas and dust, slowly revolving around the common center of mass. Gradually, the matter in the accretion disc itself began to coalesce along its lines of highest density, forming the eight planets we know today.

In the beginning, the Earth was a flaming hellscape, utterly unfit for habitation of any kind. In those early years, cosmic debris in the form of asteroids and comets regularly bombarded our tiny planet. As the drumbeat of cosmic collisions died down, the Earth once again cooled and the gases that had surrounded our planet began to coalesce. Eventually, the temperature of the water vapor began to drop below 100 C and it began its inexorable fall to the Earth. The ensuing rainstorm is thought to have raged over the surface for millions of years, ultimately blanketing the entire surface of the planet and transforming our planet from a molten ruin into tumultuous water world.

It is unclear exactly where life on this planet began, whether it began with chemosynthetic organisms in deep sea vents, extracting energy from the superheated, chemical rich water welling up from near the Earth's molten mantle. Or with more familiar, photosynthetic organisms that derive their energy from the sun. Regardless of where life first arose, it is clear that even in the earliest days, Earth possessed all of the raw materials necessary to facilitate life.

Earth possesses an abundance of Carbon, the fundamental element for all organic chemistry. Carbon's unique bonding capabilities allow it to form long, complex molecules with all kinds of other atoms. With minor amounts of energy, carbon has been shown to easily forms the basic organic buildings blocks necessary to form life, amino acids, lipids, sugars, hydrocarbons. More importantly, due to the unique bonding capabilities of carbon, organic molecules tend to combine and recombine into ever more complex organic structures. And at some point, some 900 million years after its formation, this frothing mass of organic molecules in our great global ocean did something extraordinary, something that would forever alter our planet.

It began to organize. It began to extract energy from its environment and use that energy to replicate itself.

The exact mechanism that caused the first living thing to spring into existence is unknown, it is unclear whether primitive forms of RNA or DNA began self-replicating externally or whether these complex chain of amino acids somehow ended up inside of a lipid bubble and were activated by the presence of electricity or heat or some unknown chemical reaction, but at some point, some humble collection of organic molecules began to do something this planet had never seen before. It began to live.

Creationists will argue that such a thing is impossible, that the odds of such a thing happening are akin to deriving a working 747 out of a tornado. To be sure, the odds of such an event are indeed low, but consider the simple fact that at the time life first emerged, the entire planet was covered with water, an ocean literally filled with complex organic molecules. The formation of organic molecules in and of itself, is in no way surprising as Carbon atoms love nothing more than to form exotic atomic chains. This is not an act of authorship, merely the natural result of the laws of chemistry. Given the sheer volume of organic components floating in that massive, highly energetic, seething ocean and given countless millions of years over which to combine and recombine and recombine and recombine again into increasingly complex molecular chains, far from being impossible, the emergence of life seems, inevitable.

That first humble organism, was likely an incredibly simple thing, likely capable of nothing more than extracting energy to self-replicate, but it is from these humble origins that everything we are is derived.

To say that life is a truly amazing thing is like stating that the Universe is large, it is quite simply impossible to overstate what a beautiful, graceful, powerful and phenomenal thing life is. At its most basic level, life is about organization, about taking energy from the chaotic, tumultuous world around it, and harnessing it to achieve a specific end. For these first early creatures, the specific end they sought, was simple replication. As these creatures replicated themselves over countless generations and over millions of years, it was utterly inevitable that the replication would go awry and that some variation on the original would be formed. Some of these variations would even be capable of replicating themselves, gradually creating new and different strains of life. This is the very essence of evolution.

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