The Scientific Reasons for Why I believe. (At least a couple of them anyway.)
I will admit up front that the numeric values I will list in the course of the following are not numbers that I intuitively know. I did look into them though. There are two schools of science at play for me really when it comes to support of the belief of a creator God. Considering that you already know I am a professed Christian it's not going to be hard to figure out that I have an angle to my argument. Considering that my degree is in English you also know that I am not a scientist. In fact my grammar is slipping down the drain from a lack of use. But I did get an A in Mechanical Physics...
Starting out with biology it's really a matter of the knowns that we have in conjunction with probabilities. In the Hitchhiker's Guide to the Galaxy an infinite number of monkeys want to discuss a script that they had made for Hamlet. It's a joke that is based on the notion that if you have an infinite number of monkeys banging on an infinite number of typewriters you will eventually have copies of everything that has ever been written.
Here's some of what we do know about Biology (or at least what I am pretty sure I know). The numeric values may float a little bit depending on the scientist that you talk to but this will be fairly close. Close enough for horseshoes anyway and close enough for evolution in my discussion.
-Species. A species, per the American Heritage Dictionary, is "a fundamental category of taxonomic classification, ranking below a genus or subgenus and consisting of related organisms capable of interbreeding". This definition is in fact incomplete. There are members of different species that can definitely mate but they do not produce fertile offspring (mule). The true definition of species is a group of organisms that can mate AND produce fertile offspring. This is indeed key. The only way for a new species to be created is through mutation on a genetic level.
-Variation. This is not to be confused with species. There are 35,000 genes in humans that allow for over 3 million variations inside the genetic code. These variations all work inside of the single species of humans. I do not know the number of genes for any other animal or plantlife on Earth and I don't know if they will ever map out the codes of 2 million to 100 species but I will say that they are not the same as a human and will not be able to interbreed successfully no matter how much fun they have trying. (http://www.ernestrossi.com/what_is_life.htm )
-Mutations. Mutations do happen in the genetics of all living things on earth. The vast majority of these mutations however are not favorable. Evolution relies on favorable mutation occurring over time and in a surviving relationship to the environments of the organisms at hand. So far I'm cognitively following this. Where evolution takes two steps to the right outside of my head, however, is in the sheer number of species changing and thriving over billions of years. Keep in mind that the untold millions, if not billions, of multicelled organisms over billions of years must be able to find a minimum of one other mate having THE SAME mutation and they have to get along well enough to make more of them. The odds of surviving, finding food, not getting eaten, and finding each other are maddeningly slim to me. I will not go the direction of talking about the ill effects of inbreeding within a population other than to say that it is not a good thing for one species or 100 million species.
Let's make it worse and step backwards from the organism. This could be exhaustive and I really don't want to belabor the biology side at this point. Life is to have found it's beginnings in chemicals and lightning. Michael Behe wrote a book called Darwin's Black Box. Mr. Behe is a Professor at Lehigh University in Bethlehem Pa. He is not well liked in the Biology department. I have not read the book but this is an excerpt:
page 39 of Darwin's Black Box : "By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning."
"A prime example of Michael Behe's "irreducible complexity" is the bacteria flagellum. With over 40 essential parts, the flagellum is a rotary motor used to propel a bacteria in liquid. Spinning at 17,000 rpms, the motor is acid driven, liquid cooled and self-replicating." http://www.reviewevolution.com/irreducibleComplexity.php
To see a really cool diagram of this element of the animal go to: http://www.theplan.ofgphoto.com/example.html
Ok I am done with Biology now....I'm moving on to Physics now and I promise it will be shorter.
I've found that a lot of folks in the realm of Biology get really pissed off at Physicists. Not all of them mind you but I think that some Bio's hate the fact that all of the physical reality that we know is governed by the rules of Physics. This includes Biology and Biologists. The science of Biology is governed by the science of Physics. You can't cheat Physics. You can copy and alter Biology but you just can't whip Physics. (Can you tell I like Physics?)
Anyway, I promised a shorter argument from Physics and here it is:
The Second Law of Thermodynamics: In a nutshell the natural world moves towards a natural state of maximum dis-order or a kind of equilibrium of all things. In a far larger explanation of Entropy please look at the following two paragraphs from
"Entropy and the Second Law of Thermodynamics
The second law of thermodynamics (the entropy law or law of entropy) was formulated in the middle of the last century by Clausius and Thomson following Carnot's earlier observation that, like the fall or flow of a stream that turns a mill wheel, it is the "fall" or flow of heat from higher to lower temperatures that motivates a steam engine. The key insight was that the world is inherently active, and that whenever an energy distribution is out of equilibrium a potential or thermodynamic "force" (the gradient of a potential) exists that the world acts spontaneously to dissipate or minimize. All real-world change or dynamics is seen to follow, or be motivated, by this law. So whereas the first law expresses that which remains the same, or is time-symmetric, in all real-world processes the second law expresses that which changes and motivates the change, the fundamental time-asymmetry, in all real-world process. Clausius coined the term "entropy" to refer to the dissipated potential and the second law, in its most general form, states that the world acts spontaneously to minimize potentials (or equivalently maximize entropy), and with this, active end-directedness or time-asymmetry was, for the first time, given a universal physical basis. The balance equation of the second law, expressed as S > 0, says that in all natural processes the entropy of the world always increases, and thus whereas with the first law there is no time, and the past, present, and future are indistinguishable, the second law, with its one-way flow, introduces the basis for telling the difference. The active nature of the second law is intuitively easy to grasp and empirically demonstrate. If a glass of hot liquid, for example, as shown in Figure 3, is placed in a colder room a potential exists and a flow of heat is spontaneously produced from the cup to the room until it is minimized (or the entropy is maximized) at which point the temperatures are the same and all flows stop.
Boltzmann's View of the Second Law as a Law of Disorder
The active macroscopic nature of the second law posed a direct challenge to the "dead" mechanical world view which Boltzmann tried to meet in the latter part of the last century by reducing the second law to a law of probability following from the random collisions of mechanical particles (efficient cause (see Swenson (1990)). Following the lead of Maxwell who had modeled gas molecules as colliding billiard balls, Boltzmann argued that the second law was simply a consequence of the fact that since with each collision nonequilibrium distributions would become increasingly disordered leading to a final state of macroscopic uniformity and microscopic disorder. Because there are so many more possible disordered states than ordered ones, he concluded, a system will almost always be found either in the state of maximum disorder or moving towards it. As a consequence, a dynamically ordered state, one with molecules moving "at the same speed and in the same direction," Boltzmann (1974/1886, p. 20) asserted, is thus "the most improbable case conceivable...an infinitely improbable configuration of energy." Because this idea works for certain near equilibrium systems such as gases in boxes, and because science until recently was dominated by near equilibrium thinking, Boltzmann's attempted reduction of the second law to a law of disorder became widely accepted as the second law rather than simply an hypothesis about the second law, and one that we now know fails. It became the apparent justification from physics for solidifying Cartesian incommensurability and establishing the view of the two incommensurable rivers-the "river" of biology, psychology, and culture, or the epistemic dimension of the world characterized by intentional dynamics and flowing up to increasingly higher states of order, versus the "river" of physics flowing down to disorder. Such a view is entirely inimical to a science of ecological relations, since, as noted above, it is precisely through the interface of these two rivers that these relations occur, and if the interface is incommensurable then the relations are effectively prohibited, or at best, incomprehensible."