Note: this is Part 1 of a series of posts on Christianity and Evolution. Read the introduction for more context.
1. God exists, and created everything else, including this universe we live in. And, by the way, my faith is in Christ’s death and resurrection.
The first sentence is a basic axiom, and not susceptible to proof. Though many have tried to come up with proofs for the existence of God, they all seem to contain category errors. And I think that if we define God to be the ground of all being, we can’t then try to posit something ontologically prior to explain Her. Note: I am not a philosopher, so the preceding may make no sense. Suffice it to say that I am quite content to assume the existence of God.
Much could be written on the historicity of Jesus and the validity of the Christian faith, but that’s outside the scope of the current topic. Suffice it to say that I affirm the Nicene Creed.
The question before us is how to reconcile the first few chapters of Genesis (“beginnings” in Greek) with current scientific models of the origin of the universe, the earth, and human beings.
The interpretation of Genesis that I shall argue against is “Young Earth Creationism”. In this model, the first chapter of Genesis is interpreted as a literal narrative account of the creation of the universe.
Thus, God first creates the heavens and the earth as a sort of primeval chaos. After brooding over this formless void, God creates light, and a diurnal cycle of evening and morning. Twenty-four hours later, He creates a separation between two bodies of water. Twenty-four hours after that, God gathers one of these bodies of water into the sea, uncovering dry ground. Twenty-four hours after that, She creates plants, which cover the dry ground. Twenty-four hours after that, God creates astronomical objects, including the sun and moon, which follow the diurnal cycle. Twenty-four hours after that, He creates sea creatures and birds. Twenty-four hours after that, God creates land creatures, including humans.
Note that this paragraph does not, in fact, correspond very closely to the YEC model of creation. That is because, as I shall show, the YEC model is not a literal interpretation of Genesis. It incorporates all kinds of factors for which there is absolutely no Biblical justification. More on this in Part 4.
The current scientific model goes something like this: the universe as we know it is about 14 billion years old. It originated in an infinitesimal point of highly dense and immensely hot stuff. Driven by its internal pressure, it expanded rapidly. As it expanded, it cooled, and its stuff began to differentiate into the various forms of stuff we observe today. First, matter and energy began to separate. Energy began to be felt in different ways, in gravity, electromagnetism, etc. Eventually (after about 300,000 years), the universe was a cloud of very hot hydrogen. Tiny inhomogenities or ripples in this cloud began to form structures, which gradually coalesced into finer and finer structures, until some of the structures became “super-clusters” of hydrogen, “clusters”, and finally “galaxies“. The hydrogen in the galaxies finally coalesced into spheres, which, when compressed enough by gravity, became giant thermonuclear fusion explosions — stars.
But not all the energy got turned into matter. Energy too has been spreading and thinning out as the universe expands. When scientists came up with this model of the universe (called the Big Bang), they predicted that there should be enough leftover energy to radiate throughout the universe at a temperature of about 3 Kelvins (three degrees above absolute zero). And it turns out that when you look at any part of the sky, it is indeed not quite black — there’s 3 Kelvin’s worth of energy coming at you. So every time you look into the night sky, you’re seeing the leftover fire of creation.
Now what happens in a thermonuclear reaction is this: bits of matter (hydrogen, mostly) with small atoms, get smushed together until they form larger atoms. The process releases lots of energy, which is why the stars are bright and shiny, but the main result is bigger atoms. As smaller atoms get smushed together into bigger and bigger atoms, more and more complex elements get produced: things like silicon and oxygen and carbon and nitrogen and all those nifty boxes on the periodic table. The trouble is, it’s (comparatively) easy to make hydrogen fuse. The bigger the atoms get, the harder it becomes to fuse them, so once you’ve got lots of iron and lead and uranium, say, in the middle of your star, the fusion reaction starts to fizzle. If the star is too small, it just shrinks into a brown dwarf — an invisible cinder-code silently floating in the void. But if the star has enough hydrogen left, when the central reaction fizzles, the hydrogen in the star’s outer layers suddenly collapses inwards and creates one last ginormous fusion explosion that expends all the star’s remaining energy in one shot (called a “supernova”). And all the heavy atoms in the center of the star get flung out into space in a huge cloud.
This is a photograph of the cloud left over from a supernova that Tycho Brahe observed in 1752.
Eventually, after about 5 or ten billion years, the heavy elements began to form clumps of their own mixed with the hydrogen, and when stars formed, they often had clouds of heavier material around them, which eventually clumped into “protoplanetary discs” and eventually planets.
This is a photograph of a young star with a protoplanetary disc.
Our planet, the earth, is located at a particularly useful distance from its parent star, the sun. It is at just the right temperature to allow liquid water to persist on the surface of the planet. Of the inner planets, Mercury is so close to the sun that any water or even atmosphere was stripped away long ago. Venus is still too hot for liquid water, and what water does exist is combined with liquid sulpher to produce the sulphuric acid vapor that is Venus’s atmosphere. Mars, the most habitable planet after Earth, is too cold for liquid water to remain on its surface, and too small to retain much of an atmosphere. The giant outer planets never got enough heavy elements; they are made mostly of hydrogen.
So then, earth is special because it has all this liquid water sloshing around. And water just happens to be a nice solvent for carbon-based chemistry. Among the heavy elements that supernovas spit out are carbon, oxygen, and nitrogen, just perfect for life as we know it. So eventually somewhere in this world of water and carbon and oxygen and nitrogen and myriad combinations thereof, collections of molecules arose that had the ability to reproduce themselves. People who study what’s called “emergent behavior” find that this is quite common: simple systems over time tend to display astoundingly complex behaviors, including self-replicating structures.
For example, consider a grid of squares that can be either black or white. Initialize the grid with a random collection of black and white squares. Now start a clock. At every click of the clock, flip the squares according to the following rules: a white square with exactly three black squares next to it turns black. A black square with three or more black squares next to it stays black, otherwise it turns white.
If you have a big enough grid, and time, you produce fantastically complicated patters that contain self-replicating structures.
After a long while — several billion years — these structures had developed better and better ways to replicate themselves, and they had grown in complexity to the point where we would recognize them as living organisms. After a couple more billion years (the earth is about 4 or 5 billion years old), the descendants of these organisms make up life on earth as it is today: bacteria, archaea, plants, animals, etc.
The process by which the original living organisms’ descendants ended up in such a variety of shapes and sizes is called biological evolution. Evolution operates in many different ways, but the primary one, as recognized by Darwin, is called natural selection. It is made possible because the development, structure and operation of every living thing is controlled by RNA and DNA. Each living cell — and not-quite-living-but-still-reproducing things like viruses — contains coded instructions on how to operate itself and cooperate with other cells. These instructions are encoded in long strings of RNA and DNA, and interpreted by other structures in the cell, just like a computer program is interpreted by a computer chip. When an organism reproduces itself, it passes on a copy of its RNA or DNA to its descendant.
What happens, though, if there’s an error in the copy? This is where evolution gets interesting. Errors and glitches in copied DNA can occur in many ways: cosmic or background radiation can change “letters” of the code, viruses can inject changes into the code, or . . . well, the birds and bees are simply the latest in a long line of creatures to mix-n-match genetic codes by having sex. Bacteria started it all — they tend to share random bits of their own genetic codes with other bacteria all the time. Because they reproduce so rapidly, they evolve extremely quickly. This has immediate consequences for us, as harmful bacteria can evolve new defenses for our medicines faster than we can come up with new ones. But many species have developed two parallel forms that cooperate in the mixing-n-matching process when reproducing.
The benefits of all this mixing-n-matching are many. The larger the number of members of a species with various copies of the species’ common DNA, the smaller the risk that one copying error will wipe out the species. We see this all the time when we inbreed food plants or domestic animals. When errors start creeping into the copies, it’s good to have a large reservoir of good copies to draw on. In nature, the plants or animals with the good copies survive better than the ones with the bad copies, and the population as a whole stays survivable.
The other benefit of changing and mixing and matching the genetic code is to be able to respond to changes in the environment. Sometimes copying errors creep in that don’t make any difference to the organism: changing its color from white to black, for instance. If the change doesn’t make any difference to the organism’s survivability, it may persist in the population, or it may die out. If, however, something in the environment changes, and the black organisms have a better chance of passing on their copies, then more of the population will be black. This happens when bacteria evolve resistance to a drug — among the gazillions of mixes-n-matches going on, one of them happened to enable the bacteria to survive the drug, and their genetic copies spread throughout the population. But this doesn’t only happen with bacteria. A famous example of this process is when a certain species of moth in the UK turned from white to black during the Industrial Revolution, as a result of all the coal dust all over everything.
So this process continued on to this very day. All the mixing and matching actually leaves traces in our DNA. We can see how the various genetic instructions changed and became altered as time went by. For example, every living creature that has limbs uses a gene called Sonic Hedgehog to build them, whether they’re fruit-fly legs, dolphin flippers or human arms. The differences in each species’ copy of Sonic Hedgehog tell us how long ago each species separated from its ancestors.
We recently discovered a fortuitous modification in some humans’ DNA that only dates back 700 years or so. People who have an error in their copy of a gene called CCR5 are immune to AIDS. It is estimated that this mutation first appeared in Europe during the Black Plague — only Europeans exhibit it, and it is thought to have provided protection from the plague and/or smallpox.
I think it’s obvious which model I favor. Nevertheless, as a Christian who believes that Holy Scripture is inspired by God and “useful for instruction” (II Timothy 3:16), what do I make of Genesis?