Few issues breed more tension between Atheism and Religion than evolution. Religion is and has always been incredibly hostile to the idea that our world and life are the result of natural processes. Afterall, if our world and all of the varied life on it could arise purely as a result of the physical properties and principles of matter and energy it dramatically undercuts our need for god as a means of understanding existence. Religion is ultimately an attempt to provide answers to insoluble questions. Religion's hostility to alternative answers that displace or replace millennia of Religious understanding is therefore completely understandable.
Hence Religion's hesitancy and inability to cope with the discovery that the Earth actually orbited the sun. Its inability to cope with the discovery that the Earth was a sphere. Its inability to cope with the geological and palentological evidence that the Earth was billions of years old. Its inability to cope with evolution. Religious understanding is incredibly fragile. Prone to irrationality when presented with irrefutable evidence that its understanding was misguided. Few issues typify this irrationality more than the ongoing hostility amongst the Religious community towards evolution.
To be sure, not all Religions are hostile towards evolution. Indeed, Buddhism, Hinduism, Shintoism and a host of others embrace the concept. As a general rule, however, the Monotheistic Religions, specifically Christianity and Islam remain firmly opposed to evolution despite overwhelming physical evidence.
And the evidence is overwhelming. The evidence for evolution is everywhere. Everything in our Universe evolves. Not even the dead are still. Not even inorganic matter resists evolution. Religionists often argue that objects of greater complexity cannot arise out of lesser complexity. Nothing could possibly be further from the truth.
Broadly speaking, there are two conceptually distinct forms of evolution, cosmic evolution and biological evolution. Both speak to one of the most fundamental truths in the Universe. Matter is organization.
Cosmic evolution is the process by which our Universe evolved from the random seething mass of quark-gluon plasma into the varied and marvelous structures we see spinning endlessly in the void. The process by which galaxies form and merge. The process by which stars are born. The process by which stars die, enriching the space around them and giving rise to new generations of stars. The process by which planets form out of the ashes of dead stars. The process by which all of the heavenly orbs form, evolve and die. This highly organized process does not require any divine intervention. Cosmic evolultion proceeds effortlessly due to the physical properties and principles that govern the Universe - properties that lie within our understanding.
Even at the most basic, most elemental level, matter is highly organized. Subatomic and atomic particles exhibit levels of organization and regimentation that vastly exceed the most well designed human structures ever built. A single hydrogen atom, 1/200,000,000,000,000th the size of the period at the end of his sentence maintains a coherent form in which a proton holds an electron in a spherical orbit as the electron whips around the proton at 186,000 miles per second. This feat of organization is nothing less than mind blowing.
There is no intelligence behind the form of an atom. No act of authorship causes an atom to exist. It exists because of the physical properties of matter make it so. These properties and principles are capable of understanding, capable of extrapolation, capable of testing and examination. These properties and principles are literally within our understanding! Hydrogen atoms exist because as the Universe slowly cooled from the incomprehensible tempest of the Big Bang, protons and electrons finally began to move slow enough to allow the fundamental forces to form a larger structure. Under the influence of gravity, these hydrogen atoms gradually coalesced into vast clouds of hydrogen gas and helium. These gas clouds in turn, began to collapse in on themselves under the influence of gravity, becoming ever tighter and denser forming vast galaxies. Over millions of years, incredibly dense but relatively tiny balls of gas within these titanic galaxies became massive enough to ignite through nuclear fusion, becoming the first stars and filling the Universe with light.
We can actually understand the mechanics behind existence. We can literally look through our telescopes and witness the evolution of the Universe. We can see the radiological remnants of the Big Bang. We can see the formation of the first galaxies. We can watch as they ignite in Quasars and then settle into more stable cosmic features. We can witness galaxies merging with one another. We can witness any one 400,000,000,000 stars in our own Galaxy and can watch as they evolve. We can demonstrate and predict how even the most basic building blocks of the Universe interact and function and our understanding of the fundamental forces of the Universe is actually borne out by what we see! This is a testament to the ingenuity and intelligence of our species. Not a testament to divine Authorship.
Larger, heavier atoms are even more astonishing in their complexity and incredible organization. But their design, the way they function, the way they interact with one another, the way they organize themselves, is again, not the product of any intelligence, but the physical properties of matter. These processes are discernible. And we can not only describe and understand how they function, but how they came to be. As those first stars formed in the first galaxies in the Universe, they produced heat and light and energy by fusing Hydrogen in their cores into Helium. As those stars continued to burn, they grew hotter and hotter, fusing hydrogen and helim into progressively larger atoms, carbon, silicon, oxygen, iron. Eventually, however, even the largest stars run out of fuel. The tenuous balance between the unimagiable heat generated by the star and its enormous gravity becomes unbalanced and the star explodes as a supernova.
These explosions send shockwaves rippling through the galaxy and those shockwaves cause nearby clouds of gas to collapse in on themselves, forming new stars. But unlike in the first generations of stars, the gas clouds are filled with the heavy elements from the heart of the exploding star and it is these elements that allow small rocky planets to form around stars, that allow complex atoms to combine and recombine, that enable the cosmos to continue its evolution. And it is these atoms and their amazing capacity for organization that allow biological evolution to take place.
The evolution of the Cosmos does not require the hand of the divine. It does not require any divine authorship or any guiding hand. The evolution of the Cosmos is a natural result of the physical properties and principles that govern the interactions of time, space and matter. We do not require the intervention of supernatural deities to explain the things that we do not understand, because we are finally privileged enough and technologically proficient enough to see and know and understand. We have no need to guess. We literally understand how it is that our Universe evolved and how it continues to evolve. Is our understanding perfect? Of course not.
Our understanding of the Cosmos will continue to evolve as new information, new discoveries, new patterns, and new data is gathered. Our understanding will continue to grow as we peer deeper into space and further back in time. But unlike Religious understanding, the Atheist has no need to force our understanding of the true size and scope and age of the Universe to conform to a bronze age fairy tale. The Atheist has no chains binding their understanding into a methodological framework established by shepherds and farmers with no understanding of even the most rudimentary principles of mathematics and physics. The Atheist has no need to accept the supernatural guesses of ancient peoples who wondered about the stars but lacked the technological means to understand them, because the Atheist is free to look at the data, look at the Universe and marvel not at what we guess, but at what we KNOW. And what we know is far more marvelous than even the wildest guesses of our forebearers. What we know enriches our understanding and enriches our appreciation for the indescribably amazing Cosmos that surrounds us.