Now, don't get me wrong. It's a plausible story, unlike (for example) cintelligent designism. But I find no reason to think that it is scientific. No, the fact that scientists believe it is not such a reason.
A scientific theory makes detailed (i.e. not vague) predictions. Gravitational theory permits predictions of the locations of the planets many years in advance. The predictions of evolution are rather limited. One can predict that something will survive and that it will be suited to survive in the environment in which it finds itself. Small-scale evolution is actually validated by the fact that we can simulate it (mimicking differential reproduction in electronic components) and get functioning electrical "designs" that performs tasks in ways we don't really understand. But the evolution that we can see is more like raw data. We can also see objects fall. But "objects fall" is not a scientific theory. A theory of gravity needs to predict the rate of fall.
Another thing I notice is that people will say that they do not distinguish between "microevolution" and "macroevolution" because it is all "the same theory." As I stand outside, this reminds me remarkably of the way religions will say something like "god's word does not change." Even if it were a useful predictive model over parameters we have tested, we would still not know how far it would remain useful. Newtonian gravitational theory is very useful (for dealing with objects like cars and planes.) However, it breaks down when we deal with objects approaching light speed. Appeals to "it's the same theory" does not counter the fact that theories have limitations on the parameter over which they give useful predictions. Furthermore, it is only when a discrepency is seen that we know we have run into such a limitation.
So, I don't believe that evolution is scientific. Small-scale evolution is an empirical observation -- making it true. But it is also true that Ronald Reagan was once president. That doesn't make it scientific in any way. Large-scale evolution may, in fact, be true. (We don't have the capacity to make direct observations. Just about any imaginable observation we can make could be fitted to the idea -- another trait of religions.) I certainly don't have an alternate story to propose. But it does not look scientific.
I find it interesting that scientists are human. As such they don't always apply the scientific method appropriately. For example, the grand unified "theories" that they try to use for particle physics predict that protons decay (with an incredibly long half-life.) They conducted an experiment for 12 years using enough material that it would be predicted that they would find multiple decays each year. A grand total of zero proton decays were observed. According to the scientific method, one would tentatively conclude that protons are stable (until we find evidence to the contrary.) In actuality, the scientists decided they still like their GUT's and just decided the half-life must be longer. This reminds me of the "god of the gaps." So, scientists, just like anyone else, make claims which cannot (even in principle) be falsified by any conceivable observation.