The theory of evolution is in a nutshell the theory that the variation of allele frequencies in the genomes of organisms varies with time, and that these variations can give rise to new species of organisms. This theory is most certainly testable, especially with modern DNA sequencing technology. We can actually look at organisms' genomes and determine which alleles are present. We can therefore monitor the allele frequencies in a given organism's genome over time and test to see if these frequencies do indeed change with time (they do). We can also look at cases where there are two similar organisms that are members of distinct species. Evolutionary theory would predict that these two organisms should have VERY similar genomes (indeed, they do.) We can and have also produced new species of organisms in lab experiments by the very process of selecting for the appropriate variants of the parent species, thus producing a change in allele frequencies which leads to the new species. Therefore, the theory of evolution is indeed testable, and furthermore stands up well to these tests I have described and many more as well. There are potential observations that could falsify evolution. (Precambrian rabbits, non-DNA based organisms, etc.) What potential observations could possibly falsify ID?
As stated previously, this is not a theory. At best, the first part is an observation. The second half would also be an observation, assuming it had ever been observed. In any case, this is not a theory based on the Scientific Method.
W.K.