First off, I am a trained geologist who has studied some paleontology and did some class work on extinctions and life form selectivity. Still, I am willing to give any scientific idea a fair shake, if it can stand up to scientific reasoning.
Second, I continued keeping up with extinction theory and selectivity of life based on climactic conditions.
Finally, I am separating out the actual 'designed life' from the 'seeding of life' and the anthropic (or at least intelligence allowable) universe theory. Those latter two are either: a) begging the question, or, b) entirely philosophical in nature. What I am looking at is the entire 'life is so complex it needs to have been created' concept.
Onwards and outwards!
Lets take a look at the premise of Intelligent Design:
- "The theory of intelligent design (ID) holds that certain features of the universe and of living things are best explained by an intelligent cause rather than an undirected process such as natural selection. ID is thus a scientific disagreement with the core claim of evolutionary theory that the apparent design of living systems is an illusion. "
This concept is not a new one, and, in fact, Creation Biology was around far before evolutionary theory. The current idea of Irreducible Complexity is an attempt to say that there are some elements of organisms that cannot be reduced in complexity and are, perforce, designed. These are Teleological Arguments, that attempt to say that by defining one thing as wrong with an existing theory that the entire structure of existing theory must be wrong and need to be replaced. Indeed, William Paley made similar arguments to to the modern ones in the late 18th and early 19th century. By seeing end results, they can only see design work inherent in the end result. There are a few touchstones that are commonly used to put this theory forward, basically structural ones on the function and biological role of body parts.
The oldest argument comes from eye structure, arguing that all of the components of the eye work so well together that there is no way that they could have been independently developed. As an example the human retina within the eye is held out to be of optimal design. The gross arguments, however, boil down to optimally functioning eyes not to be in the mammalia but in the cephalopodia. Just by a gross structural analysis and comparison, the human eye has many deficits. Any good electrical engineer, when designing a photo-receptive device will put the wires to actually power the device behind the photoreceptive material so as to not block absorption of light. While cephalopods have this as a feature, humans to not, and we get a wonderful view of our blood vessels in sudden bright light. This would not happen if they were put behind the retina as any competent designer would do. Another point is the human blind spot, being the point where the nerve bundle feeds into the optic nerve. This is purely structural phenomenon and is not present in many insects and cephalopods, but is in humans. Just on a gross, operational viewpoint, if this was a designed structure, it would have to be graded as sub-optimal.
Now for a bit of deeper analysis into other aspects of Intelligent Design. By claiming that the design is Intelligent and more than just 'good enough to get along', those putting forth the theory are forced into a corner about genetic variation and inheritable diseases. Now, unless you are one to say that genetic diseases of the eye are some sort of retribution or 'test' of mere mortals, one is hard put to understand the function of these things for various body parts. The body, as a whole, has an immune system particularly apt to trip over itself and start attacking its own cells that still serve a useful function, and disregard others that have gone rampant. There are two broad disease classes for these. The first are autoimmune diseases, such as Type 1 diabetes, Lupus, Optic Neuritis (that wonderful eye again), and Multiple Sclerosis. The second is known as cancer. There are other diseases and classes that would fall into this area, but these two are a direct result of a poorly functioning immune system. If anything deserves to be damn well designed, it better be the immune system of an organism. A good encoding of an immune system would have it track and catalog known diseases, have some sort of checksum analysis of cells to determine if they are functioning well or not within a body and yet be flexible enough to attack new diseases as they evolve.
Yes, diseases evolve, even the Intelligent Design people admit that, having seen it demonstrated in laboratory conditions. Easy to breed strains of things that have lifecycles measured in hours. and by applying statistical analysis, one can come up with frequency of end results in nature. So the immune system has to be complex, stable, adaptable and yet still not attack the body it is protecting, save to clean up dead or misguided cells. Note that on the plus side of the design theory is the multi-layered structure of the immune system. A complex and adaptive way of keeping problems at bay. And yet there is interference between layers which can actually cause disease and disease-like problems. Further, against things like prions and malformed protein structures, it seems to be blind. So it has limits in its adaptability against problems already known in the environment. For such problems in structure, between layers within the structure, blindness to clearly present environmental dangers and actually being harmful to a statistically important number of individuals, the immune system clearly falls short of minimal design specifications of functioning properly for all individuals.
Now onto genetic variation. Perhaps different things like eyecolor and such are just random chance put in by a designer to offer interesting differences between individuals. And different structural components, say within the eye, are...? Well the eye is supposed to be optimally designed, and to have all the necessary components for functioning properly and be structurally sound. Something like the retina actually doesn't vary much from individual to individual, and surely there are no large changes in perceptual capabilities between individuals. Putting aside blindness due to structural malformation, which can naturally occur, we come to a more serious problem of individual with tetrachromatic vision and colorblindness.
Now, what sort of Designer goes about making something that goes awry either for the better or worse? And why would a Designer do so? Why isn't the damned structure set up so that in functional parts it doesn't vary? And of course if you remove something like the lens, say, vision will get worse... unless it gets better, which has happened in the case of colleague I met 3 years ago when I was looking into other forms of receptivity. Some sufferers of cataracts also have demonstrably better vision than they did before having cataracts. It would seem that the lens, so necessary for functioning, can be removed and actually *improve* the design. Intelligent? Design?
The quick course on scientific theories.
First off, a scientific theory must not only explain a class or group of phenomenon, but it must do so consistently across that class or grouping. Also, any new theory must not only encompass all previous work, but explain problems with that previous model and give a consistent and expanded view of those previous models.
- One of the prime examples of this is Relativity. Previous Newtonian mechanics, which had done a wonderful job of explaining such things as orbital mechanics of the planets and other celestial bodies, was showing problems on the large scale (particularly the orbit of Mercury) and when velocities were approaching those of half the speed of light. Relativity not only explained those problems and shifted the frame of reference, but included all of Newtonian work retaining its mathematical setup with provisos on where it breaks down and why. Relativity mathematics can be used for all of Newtonian mechanics.
- Again, Relativity made prediction on how light acts in a gravity field, the dynamics of matter in very condensed states and gave a theoretical underpinning for why the speed of light is an absolute limit and what happens when masses approach that limit.
- The limits of Relativity have proven to be at the Quantum scale and in establishing a Grand Unified Theory of forces in the universe. Anything that supplants Relativity must not only take it into account, but fix the problems it has and expand the field of knowledge by making predictions within its framework that can be tested. If the tests do not run as predicted, then the theory would prove to be inconsistent and not explain things better.
On the first count, Intelligent Design, by not properly encompassing variation within populations nor the propagation of such variations does not pass the first test of encompassing Evolutionary theory. Problems in structural design of organs, overall use of body-wide systems and explaining the utility of multiple copies of genes in a genome are not well covered by Intelligent Design, but easily so by Evolutionary theory. Evolutionary theory explains why certain genetic traits are retained and others not over time. In particular, genetic analysis of life forms is proving out how genes and genetic material move within groups to cause species to occur. By including an inheritance mechanism and making it a part of Evolutionary theory, we gain understanding of commonality between species in families on the tree of life. This has spurred development of such things as Cladistics, which does an excellent job of tracing common ancestry through speciation events and pointing to genetic factors as the underlying causes.
On the second count, Intelligent Design, by not encompassing problems in Evolutionary theory and incorporating such things as genetic analyses, conservation of some genes over others and variations does not expand the basis of knowledge nor offer areas into which new predictions can be made. Evolution is testable via morphology of species, genetic testing within groups of similar species and by explaining differential heredity of mutations over time. By offering mechanisms by which this things happen and why they happen, Evolutionary theory both answers and explains such things and predicts that this is an ongoing process that can be understood and measured. Intelligent Design must, perforce, encompass areas ranging from basic chemistry and biochemistry, inheritance mechanism, explain how inherited traits are expressed, explain how variations arise in species populations, offer a means and methodology for how speciation occurs, take into consideration environment and habitat, and, most of all explain anomalies in the current theory while encompassing it and making it a subset of this new theory. From that new theory it must offer testable insights into genetics, mutations, inheritance, biochemistry, environment and speciation events.
Finally, Intelligent Design must be falsifiable in its predictions. As it stands Intelligent Design offers an answer (i.e. species were intelligently designed) without an explanation that offers insight into scientific areas of knowledge. Further, by not stating what that Intelligent Design actor actually *is*, it does not offer falsifiability. What is the nature of this Designer? That must be clearly stated, be it a Deity or set thereof, space aliens or some blind thinking force within the universe. It must give mechanisms for how that Design work is carried out, how and why it changes over time and, finally, make testable predictions on how to better understand and duplicate such work. It must also make predictions on future changes based on the understanding of its work. Intelligent Design must do *all* of that and *still* retain Evolutionary theory as a subset of itself or offer a better set of understandings for why evolution happens.
If Evolution is an "illusion", then Intelligent Design needs to step up to the plate on biochemistry, genetics, inheritance, speciation, extinction, morphology, and variations within populations and environmental response of all of that to a changing environment. It must, basically, supplant all knowledge in those areas with something a damn sight better than Evolutionary theory. And *still* be testable, verifiable, predictable and falsifiable. Intelligent Design may be a philosophy, but it is not science by those standards. Evolutionary theory is a science by those standards.