The remarkable thing about Darwin's theory is it does not change; after 150+ years, it is still just as Darwin proposed it. It seems remarkably resistant to modification based on new evidence, observational capabilities, and understandings. IOW, it appears to be strikingly "complete." And yet on the other hand....
How long were were geocentric theory and Newtownian mechanics considered accepted theory before they were supplanted? You make it sound as if a theory being unchallenged for 150 years is an historic anamoly.
It does sound like you are straining to find fault.
I read an outstanding defense of methodological naturalism (as opposed to metaphysical naturalism) the other day. You can read it here.
Quote:
It is not inconsistent to claim there is more going on in the evolutionary process than is dreamt of in evolutionary biology. This is the thesis that there are "hidden variables" — causal influences on evolutionary outcomes that are not recognized in our science. If evolutionary theory were causally complete, there would be no room for this idea. However, we have no assurance that the theory covers all the facts that are causally relevant to what happens in evolution. Please note that I am not saying that there now is evidence that such hidden variables exist; my claim is only that they are not ruled out by current theory.But it is clear that Richard Dawkins — the great promoter and popularizer of Darwin's theory — does rule them out in principle. For he declares that Darwin's theory allows him to be "an intellectually fulfilled atheist."
This is what drives theists (like me) nutz.
But as the author of the linked article — Elliott Sober, of the Philosophy Department at the University of Wisconsin — points out, when it comes to the idea of possible divine intervention in the world of space and time after the evolutionary process is underway, we have to ask
...what does "divine intervention" mean? In theology, it is often understood to mean God's violating the laws of nature. I do not use the term in this way. [Neither do I.] What I want to consider ... is the view that God supplements what happens in the evolutionary process without violating any laws. [God cannot contradict Himself.] An intervention, as I'll understand the term, is a cause; it can trigger an event or sustain a process. Physicians do both when they intervene in the lives of their patients. Physician intervention does not entail any breakage in the laws of nature; neither does God's.Actually, I understand that this was Newton's understanding.
Sober's analysis
...say[s] nothing about whether there have ever been mutations in the whole history of life that God made sure would happen. Scientists do not have a way of testing this theistic assertion. However, that does not show that it is false. Scientists sometimes use the derisive comment "not even false" to characterize hypotheses that cannot be tested. The derision can be separated from a point on which theists and atheists should agree: there is a difference between hypotheses that the evidence tells us are false and hypotheses that our data do not permit us to test....To the extent that Darwin's theory is often depicted in the light of metaphysical naturalism — as Dawkins does — and not methodological naturalism (which "keeps its mind open," as explained above), it has more of the flavor of a religious creed than of a scientific theory.
Is every statement in a scientific theory testable? Mathematized theories in biology and in other sciences entail that numbers exist. Is the existence of numbers empirically testable? ...
Carnap (1950) and Reichenbach (1938), among other positivists, held that scientific theories often contain conventional elements. These are statements that are in a theory because they are useful, not because we can offer evidence that they are true.
Or I should say, an antireligious screed.
To the extent that such an understanding of evolution theory prevails, we can understand the promoters of Darwin's theory to be more defending a dogma than engaging in "open" scientific inquiry.
This observation can shed some light on why Darwin's theory has remained fundamentally unchanged for 150+ years: It is a fact of human nature that people will tenaciously defend a religious doctrine "come hell or high water."
But that's not science! Science must remain "open." It cannot just assume causal closure about any aspect of the natural world.
If it does, it eventually puts itself out of business.
FWIW.
It does sound like you are straining to find fault.
Actually, I have to disagree with Betty Boop here. The idea that Darwinism has been stagnant and unchanging for 150+ years. Of course she's correct scientifically, but consider:
You see, each time it's challenged or new information comes forth, liberals that support it circle the wagons and attack those that dare to disagree or even present new challenges. There's no rational scientific defense of Darwinism, but only tired used up failed liberalspeak. If anyone suggests a flaw, then their credentials are attacked. Or they get shouted down and ran off with some farcical peer review.
Case in point, what's this unchallenged for 150 years nonsense? The better question is of course: What scientific theory requires so many lawsuits to prop it up?
The ToE has not been unchallenged for 150. the evo supporters just wish it were so and therefore claim it leading the gullible to believe that is the case.
The problem is that ToE supporters blow off any challenge as being unscientific by default. The challenges are dismissed off hand.
However, their considering that there is no valid scientific challenge to the ToE does not make it so.