The theory of evolution may in fact not be falsifiable. However, it is unknown whether or not it is falsifiable. In a sense, the original author is suggesting that because we can not conceive of a way to falsify the theory, then it is not a theory. But there are likely other things that we can not conceive of ways to falsify, or as yet, may not be falsifiable, that we fully believe or have believed to be "truth." Among these are the notion that the Earth is flat, that the Earth was the center of the Cosmos, and similarly related "nutty" ideas. But, as time goes forward, we find ways to begin to question the theories, yes, even laws, of nature which we had once found to be so true. And, we devise ways to falsify them if possible.

Now then, I dont want to take an official stand that the theory of evolution is not "true" or that it is not a theory. Quite the contrary, I have great faith in the general logic in it. However, I do want to suggest that it might be falsifiable, but we have not devised ways to falsify it ( And of course, it is at least possible that it is not falsifiable at all because empirical reality is such that no counter examples occur. If this is the case, then evolution is not discarded for lack of "theory-ness", rather it becomes a scientific law... but time will (tell.)

That the theory of evolution is not predictive is nonsense to assert and silliness to believe. There are predictions that can be made about the overall development of life on Earth using the theory of evolution as a guide. The problem, it seems to me, is that being able to generate the empirical data that would confirm or disconfirm those predictions is something beyond the likely time-line of most people. Thus, it becomes a bit tought to engage in prediction of events. However, what we can in fact do is examine empirical evidence to see if the data match the predictions we might have made previously: post-dicting. The contention that this IS NOT the SCIENTIFIC METHOD is wholly unsustainable. That is in fact what the scientific method is about.

Finally, I refer the kind reader to the book FULL HOUSE by Stephen Jay Gould. Here he takes an interesting tack on the theory of evolution where he suggests that contrary to the normal thinking that evolution tends towards specialization and complexity, evolution mostly tends to generate simplicity. That nutshell review of the argument is in itself simplicity, so please, if you are curious, pcik up the book.