The observed changes are brought about by a sophisticated adaptation machine that we are only beginning to figure out. Evolution does not explain the machine, much less why such adaptation should be viewed as evidence for large-scale, macro evolutionary change. Indeed, evolutionists in the know have long since questioned the notion that adaptive change leads to the needed macro evolutionary change.
So why do evolutionists routinely claim that adaptive change is powerful evidence--observable proof of evolution? Weiner's lecture will focus on chapters one and two of Darwin's book and here we find a clue. Darwin discusses biological variation and in the summary of chapter two he states that the evidences he has presented "are utterly inexplicable if species are independent creations." And if the species were not independently created then they must have evolved, one way or another.
Obviously Darwin had a specific idea in mind of what the species should look like if they had been independently created. The idea came from the eighteenth century Swedish mastermind botanist Carl Von Linne, and for evolutionists its falsification proves their theory.
Biological variation and adaptation demonstrate evolution not because they ultimately supply the needed large-scale change, but because they refute the alternative. As explained in Darwin's God:
Linnaeus’ fixity of species concept could accommodate an old earth, with its multiple creation events or successive revolutions. It could even accommodate extinctions. But it could not survive if science were to find that new species were routinely created by unguided natural forces.
Linnaeus was troubled when he discovered hybrids—species that are produced by the crossing of two related species—and he later softened his doctrine of fixity of species. But this was inconsequential: his system with its conception of species became deeply rooted, and the nineteenth century began with the notion of species as immutable still strongly in place.
This notion was increasingly being challenged but it was nonetheless a major obstacle for Darwin to overcome.
It was therefore highly significant when Darwin became persuaded that related populations of birds he saw at the Gallapagoes were actually different species. If there was the slightest foundation for this idea, Darwin had written in a famous notebook entry, it “would undermine the stability of species.”
The birds did not suddenly reveal to Darwin how fishes could change to amphibians, or how amphibians could change to reptiles, or how reptiles could change to mammals. Rather, the revelation was that the idea of creation held by the modern mind, was suddenly becoming untenable. The crucible for Darwin was not an abundance of positive evidence for evolution but rather negative evidence against creation.
Evolutionist Ernst Mayr has pointed out that Darwin’s conversion from creationist to materialist was due to three key scientific findings and later reinforced by several additional findings. These scientific findings were all findings against creation. In other words, the key evidence that swayed Darwin was not direct evidence for evolution but rather evidence against creation that indirectly argued for evolution.
And as Mayr further points out, the doctrine of fixity of species was a key barrier to overcome in order if the concept of evolution was to flourish:
"Darwin called his great work On the Origin of Species, for he was fully conscious of the fact that the change from one species into another was the most fundamental problem of evolution. The fixed, essentialistic species was the fortress to be stormed and destroyed; once this had been accomplished, evolutionary thinking rushed through the breach like a flood through a break in a dike."
The pre-Darwinian metaphysic was that species were fixed and essentialistic. Evidence for small-scale change argued against the old view and in so doing became important evidence for evolution.
The question for Weiner is then: Is it proper for scientists to incorporate metaphysical assumptions in their theories? Religion drives science, and it matters.