Geology diametrically opposes theism in one word: meteorites. Did a deity really go through all that trouble to meticulously plan billions of years of development specifically to have a few thousand years of existence for humans?
Intelligent Design generally ascribes to the “anthropic principle”. The strong anthropic principle (SAP) states that the Universe is compelled, in some sense, for conscious life to eventually emerge. Critics of the SAP argue in favour of a weak anthropic principle (WAP) which states that the universe’s ostensible fine tuning is the result of selection bias: i.e., only in a universe capable of eventually supporting life will there be living beings capable of observing any such fine tuning, while a universe less compatible with life will go unbeheld.
In short, sophisticated theists who support the concept (knowingly or not) of Intelligent Design, maintain that the evolution of life and more importantly intelligent life was inevitable and indeed planned and executed by a supernatural being in the past and at present. Humans are the Raison d’être for the very large scale and elaborate design of the universe, solar system and earth.
The geologic record has much to say about our being here. We know that approximately 99.9% of all species that ever existed are already extinct. It’s impossible to determine the precise reasons for each species going extinct suffice to say that they simply lost out in the ceaseless dynamic (ever-changing) natural system. Many millions of species disappeared in 5 well recorded mass extinction events as follows:
· 85% of species at the end of the Ordovician (~440 Ma);
· 80% of species at the end of the Devonian (~360 Ma);
· 96% of species at the end of the Permian (~252 Ma);
· 76% of species at the end of the Triassic (~201 Ma); and
· The most famous of all ~75% of all species at the end of the Cretaceous (~66 Ma)
Many hundreds of small scale extinction events, some global and others local, are also recorded in the geological record.
Some of the causes of the mass extinction events are not known and are the subject of some debate. So let’s consider the most famous and arguably best studied extinction event – the one that ended the 165 million year reign of the dinosaurs at the end of the Cretaceous, 66 Ma. It has now been fairly well established that an impact by a sizable projectile from space caused the abrupt end of the dinosaurs. Mammals co-existed with dinosaurs, but the removal of the dinosaurs from the ecological niches resulted in dramatic changes and the emergence and eventual dominance of mammals.
Suppose the projectile from space had missed earth instead of colliding with it? What would the earth be like today? Chances are that mammals would either be extinct or still eking out a precarious living on the fringes of a dinosaur dominated planet. Now ask yourself, has a deity ever been observed pushing minor projectiles around in the cosmos/solar system?
This raises a profound question: how inevitable was the evolution of an intelligent mammalian life form, Homo Sapiens Sapiens? Humans are quite literally the product of a cosmic accident (the impact of the Cretaceous projectile) 65 million years ago, coupled with literally hundreds of other chance events before and after the impact over millions/billions of years. The long geological record of extinctions and mass extinctions tells us in no uncertain terms that in the grand scheme of things Homo Sapiens are not the centre of all things and that extinction can happen tomorrow to any species.
And so, to get back to theism! In order to be a theist, someone who believes in an intervening, governing, organising deity, this is what you have to believe. You have to believe that 65 million years ago a deity steered on purpose, with full knowledge of 66 million years of evolution still ahead, a projectile of precisely the correct size, speed and energy, into precisely the correct spot on earth, at precisely the correct time in the evolutionary trajectory of species on earth, knowing that in doing so this would result in Christian, Islam, Hindu and thousands of other deities being worshipped by an intelligent mammalian species who would all “know” for sure their version of deity was the one who did the deed.
Tyrannosaurus rex, Palais de la Découverte, Paris
Now you need to apply your mind still further. Take the example above from the Cretaceous mass extinction and multiply that by the orders of magnitude of time 66 million years out of 4 500 million years of earth’s history (never mind the preceding 9 300 million years of universe history) and you will comprehend the staggering array and vastness of chance events that resulted in the existence of intelligent life on earth.
To think that some deity (and it appears no one knows exactly which one) had a hand in helping this along at every step of the intricate path on a second by second basis is incomprehensible and nonsensical, even more so given the sheer immensity of the universe with over 200 billion stars in our own galaxy (Milky Way) and the billions of galaxies each with their billions of stars, most as it now transpires, with a multitude of orbiting planets.
Maybe geology does not provide conclusive proof that there is no God, but it certainly shows that the existence of a deity is highly improbable.