Creationists continue to try to find single species examples or general statements such as “irreducible complexity” to undermine evolution. The problem is that simple logic based on the fossil records results in one of two conclusions – either evolution is true, or creation is a continuous event.
Even creationists acknowledge that natural selection within a species is demonstrably true. Creationists argue that Darwin's finches and pepper moths are changes within a species change and not evolution. Things like island based dwarfism are also just intra-species change, but not speciation. These examples demonstrate natural selection without full blown evolution. If you deny even this form of natural selection, then stop reading because what follows will simply make you angry.
Other modern examples of natural selection include drug resistant bacteria, chemically resistant weeds, and pesticide resistant insects. The flu virus mutates as it passes through people bypassing the immunities generated to its earlier forms, which is one of the reasons why the flu shot changes most years. Positive mutation and natural selection are demonstrable within our lifetime. Most species have not changed much within our lifetime, but there are some very testable examples such as bacteria, plants, insects, and other micro-organisms.
Assuming natural selection is acceptable, but evolution is not, is it possible that evolution is sometimes true? The most strongly supported example of evolutionary change over time is the modern day horse. It has the most complete transitional fossil record of any species living today. Spend a little time on Wikipedia for a bite sized explanation of equine evolution. It is hard to explain the fossil record of horses without accepting that evolution is at least sometimes true. If evolution is never true, how do we explain how both modern horses and pre-historic horses have no contemporaneous fossils? Either creation is a continuous event, meaning the creator is constantly adding new species as other species die out, or speciation occurred through transition. Horses are far from the only example of animals with clear transitional species. What about Neanderthals? What about the transitional forms of elephants? There are thousands of examples with millions of fossils. Even if you reject carbon dating, sediment layers consistently show the time sequencing of different species. If you reject this assertion of clear physical evidence of evolution being at least sometimes true, then stop reading now because you'll only get angrier.
Let's assume that evolution is sometimes true but fails as a general theory. One of the common counterpoints is that a few species that appear to be static for an extended period of time. Let's examine what that means. Natural selection means that change benefits the species or individual organism or it causes no harm. Change that causes harm means the offspring with the negative change die off more frequently than offspring without the variation. If a species is well suited to its environment and experiences no external pressures by species changing around it, then it will not change. There are a handful of species that demonstrate this lack of change for an extended period of time such as the lungfish. This is called evolutionary stasis.
Incomplete evidence of evolution for a single species does not invalidate the whole theory because there is no better explanation for the whole of the evidence or the perceived exceptions. The evidence we have today requires one of two explanations - either evolution is true or creation is continually occurring. People have never witnessed the act of "creating" a new species. Consequently, we have no evidence that creation is continually occurring, so it must be evolution that is the better theory.
Creationists can still salvage a form of creation by going with the hypothesis that the creator initiated life and set evolution in motion. However, this is where we would have to legitimately part ways. In my opinion, no one knows for sure how life started, which justifies no explanation other than "we don't know." However, theistic evolution is still evolution.