One of the principal claims of Mr. Darwin's theory to acceptance is, that it enables us to dispense with a law of progression as a necessary accompaniment of variation. It will account equally well for what is called degradation, or a retrograde movement towards a simpler structure, and does not require Lamarck's continual creation of monads; for this was a necessary part of his system, in order to explain how, after the progressive power had been at work for myriads of ages, there were as many beings of the simplest structure in existence as ever.

In Darwin's theory, you just have to substitute 'mutations' for his 'slight accidental variations' (just as quantum theory substitutes 'quantum jump' for 'continuous transfer of energy'). In all other respects little change was necessary in Darwin's theory...

There can be no question that Darwin had nothing like sufficient evidence to establish his theory of evolution. . . . His general theory, that all life on earth had originated and evolved by a gradual successive accumulation of fortuitous mutations, is still, as it was in Darwin’s time, a highly speculative hypothesis entirely without direct factual support and very far from that self-evident axiom some of its more aggressive advocates would have us believe. . . . One might have expected that a theory of such cardinal importance, a theory that literally changed the world, would have been something more than metaphysics, something more than a myth.

"The extreme rarity of transitional forms in the fossil record persists as the trade secret of paleontology. The evolutionary trees that adorn our text- books have data only at the tips and nodes of their branches; the rest is inference, however reasonable, not the evidence of fossils. Yet Darwin was so wedded to gradualism that he wagered his entire theory on a denial of this literal record:

"The geological record is extremely imperfect and this fact will to a large extent explain why we do not find interminable varieties, connecting together all the extinct and existing forms of life by the finest graduated steps, He who rejects these views on the nature of the geological record, will rightly reject my whole theory."

Darwin's argument still persists as the favored escape of most paleontologists from the embarrassment of a record that seems to show so little of evolution. In exposing its cultural and methodological roots, I wish in no way to impugn the potential validity of gradualism (for all general views have similar roots). I wish only to point out that it was never -seen- in the rocks.

Paleontologists have paid an exorbitant price for Darwin's argument. We fancy ourselves as the only true students of life's history, yet to preserve our favored account of evolution by natural selection we view our data as so bad that we never see the very process we profess to study.
[Evolution’s Erratic Pace - "Natural History," May, 1977]"

Darwinism is not a theory of random chance. It is a theory of random mutation plus non-random cumulative natural selection. . . . Natural selection . . . is a non-random force, pushing towards improvement. . . . Every generation has its Darwinian failures but every individual is descended only from previous generations' successful minorities. . . . [T]here can be no going downhill - species can't get worse as a prelude to getting better. . . . There may be more than one peak.

I adopt Mr. Darwin's hypothesis, therefore, subject to the production of proof that physiological species may be produced by selective breeding; just as a physical philosopher may accept the undulatory theory of light, subject to the proof of the existence of the hypothetical ether; or as the chemist adopts the atomic theory, subject to the proof of the existence of atoms; and for exactly the same reasons, namely, that it has an immense amount of primâ facie probability: that it is the only means at present within reach of reducing the chaos of observed facts to order; and lastly, that it is the most powerful instrument of investigation which has been presented to naturalists since the invention of the natural system of classification and the commencement of the systematic study of embryology.

The fundamental core of contemporary Darwinism, the theory of DNA-based reproduction and evolution, is now beyond dispute among scientists. It demonstrates its power every day, contributing crucially to the explanation of planet-sized facts of geology and meteorology, through middle-sized facts of ecology and agronomy, down to the latest microscopic facts of genetic engineering. It unifies all of biology and the history of our planet into a single grand story. Like Gulliver tied down in Lilliput, it is unbudgable, not because of some one or two huge chains of argument that might — hope against hope — have weak links in them, but because it is securely tied by thousands of threads of evidence anchoring it to virtually every other area of human knowledge. New discoveries may conceivably lead to dramatic, even "revolutionary" shifts in the Darwinian theory, but the hope that it will be "refuted" by some shattering breakthrough is about as reasonable as the hope that we will return to a geocentric vision and discard Copernicus.

It appears to us to be one of the many peculiar merits of that [Mr. Darwin's] hypothesis that it involves no belief in a necessary and continual progress of organisms.

A seeker after Truth cannot afford to indulge in generalisation. Darwin for the greater part of his book Origin of the Species [sic] has simply massed fact upon fact without any theorising, and only towards the end has formulated his conclusion which, because of the sheer weight of testimony behind it, becomes almost irresistible. Yes I have criticised even Darwin's generalisation as being unwarranted. Science tells us that a proposition may hold good in nine hundred ninety-nine cases and yet fail in the thousandth case and thus be rendered untenable as a universal statement.

Like Kant before him, Darwin insists that the source of all error is semblance. Analogy, he says again and again, is always a ‘deceitful guide’ (see pp. 61, 66, 473). As against analogy, or as I would say merely metaphorical characterizations of the facts, Darwin wishes to make a case for the existence of real ‘affinities’ genealogically construed. The establishment of these affinities will permit him to postulate the linkage of all living things to all others by the ‘laws’ or ‘principles’ of genealogical descent, variation, and natural selection. These laws and principles are the formal elements in his mechanistic explanation of why creatures are arranged in families in a time series. But this explanation could not be offered as long as the data remained encoded in the linguistic modes of either metaphor or synecdoche, the modes of qualitative connection. As long as creatures are classified in terms of either semblance or essential unity, the realm of organic things must remain either a chaos of arbitrarily affirmed connectedness or a hierarchy of higher and lower forms. Science as Darwin understood it, however, cannot deal in the categories of the ‘higher’ and ‘lower’ any more than it can deal in the categories of the ‘normal’ and ‘monstrous.’ Everything must be entertained as what it manifestly seems to be. Nothing can be regarded as ‘surprising,’ any more than anything can be regarded as ‘miraculous.’

...it was Darwin’s chief contribution, not only to Biology but to the whole of natural science, to have brought to light a process by which contingencies a priori improbable, are given, in the process of time, an increasing probability, until it is their non-occurrence rather than their occurrence which becomes highly improbable. … Let the reader … attempt to calculate the prior probability that a hundred generations of his ancestry in the direct male line should each have left at least one son. The odds against such a contingency as it would have appeared to his hundredth ancestor (about the time of King Solomon) would require for their expression forty- four figures of the decimal notation; yet this improbable event has certainly happened.

Darwin’s model of evolution . . . , being basically a theory of historical reconstruction, . . . is impossible to verify by experiment or direct observation as is normal in science . . . Moreover, the theory of evolution deals with a series of unique events, the origin of life, the origin of intelligence and so on. Unique events are unrepeatable and cannot be subjected to any sort of experimental investigation.

Trained in a less severe school than that of geometry and physics, his reasonings are almost always loose and inconclusive. His generalizations seem to have been reached before he had obtained the materials upon which he rests them: His facts, though frequently new and interesting, are often little more than conjectures; and the grand phenomena of the world of life, and instinct, and reason, which other minds have woven into noble and elevating truths, have thus become in Mr. Darwin's hands the basis of a dangerous and degrading speculation.

Physiologic facts concerning the origin of species in nature were unknown in the time of Darwin. . . The experience of the breeders was quite inadequate to the use which Darwin made of it. It was neither scientific, nor critically accurate. Laws of variation were barely conjectured; the different types of variability were only imperfectly distinguished. The breeders' conception was fairly sufficient for practical purposes, but science needed a clear understanding of the factors in the general process of variation. Repeatedly Darwin tried to formulate these causes, but the evidence available did not meet his requirements. Quetelet's law of variation had not yet been published. Mendel's claim of hereditary units for the explanation of certain laws of hybrids discovered by him, was not yet made. The clear distinction between spontaneous and sudden changes, as compared with the ever-present fluctuating variations, is only of late coming into recognition by agriculturists. Innumerable minor points which go to elucidate the breeders' experience, and with which we are now quite familiar, were unknown in Darwin's time. No wonder that he made mistakes, and laid stress on modes of descent, which have since been proved to be of minor importance or even of doubtful validity.