Evolution simply has never been observed.
For example i have several pets, some are several years old. Yet they haven't evolved. How will the evolutionist respond to this? Here's what they will say:
''no you stupid creationist. how do you espect something to evolve in only a few years! it takes millions.''
Yet, Millions of years is not observable. Evolution is based on this fairy tale logic of vast periods of time.
If you mean that natural selection has never been observed, then you are flat wrong. It is often observed, and has been observed to create portions of genes in labs. For instance, when the D2 domain of coliphage fd's g3p minor coat protein (which it needs to be infectious) was replaced with a random sequence of 139 amino acids and subjected to random mutagenesis. A 240-fold increase in fitness was observed after only 7 generations, eventually reaching a maximum of a 17,000-fold increase (Hayashi et al., 2006).
Natural selection has even been observed to create entirely new genes in labs; by subjecting
Pseudomonas aeruginosa to a nylon-rich environment, mutations that caused the formation of both 6-aminohexanoate cyclic dimer hydrolase and 6-aminohexanoate dimer hydrolase were retained (Prijambada et al., 1995).
But if you mean that the evolutionary model is unscientific because the speciation events that lead to the diversity of life happened in the pastand thus cannot be observedthen you are misunderstanding how science works. Science is not just about making observation; but also about forming models of the unobservable that most parsimoniously fit the most observation, and seeking to make more observations to test the validity of the models.
The roll of microorganisms in disease, or the existence of atoms, for instance, was once purely based on inference. Now, we can observe them; but even if we couldn't, that wouldn't make the models unscientific.
When past events are accessed, all one can ever do is draw inference. But again, that doesn't make the models unscientific.
And in regards to your pets; the reason they are not evolving is because (contrary to Lamarck's model) the phenotypic change doesn't occur in the organisms themselvesit occurs in the organisms' offspring. So it's populations of organisms that evolvenot the organisms themselves.
If you look at the process of domestication, such as dog breeding (artificial selection), you will see phenotypic and genotypic change. But the reason this doesn't result in entirely new organisms is because the selection is taking place over such a short period of time, that it is only acting on preexisting phenotypically expressed genetic variation. The majority of the domestic dog breeds, for instance, have been created in just the past few hundred years, and not only are they quite genetically diverse (Parker, Sutter, & Ostrander, n.d.), but there is an extremely small genetic difference between them and the grey wolves from which they recently diverged (Savolainen, n.d.; Leonard, Vila, & Wayne, n.d.).
Simply put, a major limit on the effect of natural and artificial selection over short periods of time is that they act on preexisting variation. When you allow mutation to add to that variation over long periods of time, the changes can accumulate to form new genera, families, orders, etc.
As a side note, what dog breeding demonstrates is how large genetic variation in even phenotypically uniform populations correlates to an enormous range of potential phenotypes. This allows populations to adapt to new environmental pressures, even when the change is rapid and drastic. Rather than simply being wiped out, the population can persist long enough for further adaptation by natural selection acting on the genetic variation slowly introduced by mutation. Populations with larger variation have more of a built-in safeguard against being decimated by a changing environment.
References
Hayashi, Y., T. Aita, H. Toyota, Y. Husimi, I. Urabe, and T. Yomo. "Experimental rugged fitness landscape in protein sequence space."
PLoS One 1.E96 (2006).
Leonard, J. A., C. Vila, and R. K. Wayne. "From Wild Wolf to Domestic Dog." In: Ostrander, E. A., U. Giger, and K. Lindblad-Toh, eds.
The genome of the domestic dog. New York: Cold Spring Harbor, 2006. 95118.
Parker, H. G., N. B. Sutter, E. A. Ostrander. "Understanding Genetic Relationships Among Purebred Dogs: The PhyDo Project." In: Ostrander, E. A., U. Giger, and K. Lindblad-Toh, eds.
The genome of the domestic dog. New York: Cold Spring Harbor, 2006. 141158.
Prijambada, I. D., S. Negoro, T. Yomo, and I. Urabe. "Emergence of Nylon Oligomer Degradation Enzymes in
Pseudomonas Aeruginosa PAO through Experimental Evolution."
Appl Environ Microbiol 61.5 (1995 May): 2020-2.
Savolainen, P. "mtDNA Studies of the Origin of Dogs." In: Ostrander, E. A., U. Giger, and K. Lindblad-Toh, eds.
The genome of the domestic dog. New York: Cold Spring Harbor, 2006. 119140.
