Circular Reasoning in Evolutionary Biology
by Henry Morris, Ph.D.
Creationists have long insisted that the main evidence for evolution — the fossil record — involves a serious case of circular reasoning. That is, the fossil evidence that life has evolved from simple to complex forms over the geological ages depends on the geological ages of the specific rocks in which these fossils are found. The rocks, however, are assigned geologic ages based on the fossil assemblages which they contain. The fossils, in turn, are arranged on the basis of their assumed evolutionary relationships. Thus the main evidence for evolution is based on the assumption of evolution.
A significant development of recent years has been the fact that many evolutionary geologists are now also recognizing this problem. They no longer ignore it or pass it off with a sarcastic denial, but admit that it is a real problem which deserves a serious answer.
The use of "index fossils" to determine the geologic age of a formation, for example, is discussed in an interesting way in an important recent paper by J.E. O'Rourke.
"These principles have been applied in Feinstratigraphie, which starts from a chronology of index fossils, and imposes them on the rocks. Each taxon represents a definite time unit and so provides an accurate, even 'infallible' date. If you doubt it, bring in a suite of good index fossils, and the specialist without asking where or in what order they were collected, will lay them out on the table in chronological order."1
That is, since evolution always proceeds in the same way all over the world at the same time, index fossils representing a given stage of evolution are assumed to constitute infallible indicators of the geologic age in which they are found. This makes good sense and would obviously be the best way to determine relative geologic age — if, that is, we knew infallibly that evolution were true!
But how do we know that? There is such a vast time scale involved that no one can actually observe evolution taking place.
"That a known fossil or recent species, or higher taxonomic group, however primitive it might appear, is an actual ancestor of some other species or group, is an assumption scientifically unjustifiable, for science never can simply assume that which it has the responsibility to demonstrate. — It is the burden of each of us to demonstrate the reasonableness of any hypothesis we might care to erect about ancestral conditions, keeping in mind that we have no ancestor alive today, that in all probability such ancestors have been dead for many tens or millions of years, and that even in the fossil record they are not accessible to us."2
There is, therefore, really no way of proving scientifically any assumed evolutionary phylogeny, as far as the fossil record is concerned.
"Likewise, paleontologists do their best to make sense out of the fossil record and sketch in evolutionary sequences or unfossilized morphologies without realistic hope of obtaining specific verification within the foreseeable future."3
It would help if the fossil record would yield somewhere at least a few transitional sequences demonstrating the evolution of some kind of organism into some other more complex kind. So far, however, it has been uncooperative.
"The abrupt appearance of higher taxa in the fossil record has been a perennial puzzle. — If we read the record rather literally, it implies that organisms of new grades of complexity arose and radiated relatively rapidly."4
Transitions are well documented, of course, at the same levels of complexity — within the "kinds," that is — but never into "new grades of complexity." Horizontal changes, however, are not really relevant to the measure of geologic time, since such changes occur too rapidly (e.g., the development of numerous varieties of dogs within human history) to be meaningful on the geologic time scale, and are reversible (e.g., the shift in the peppered-moth population of England from light-colored to dark-colored and back again).
Thus vertical evolutionary changes in fossils are essential to real geologic dating, but they are impossible to prove. They must simply be assumed.
The dating of the rocks depends on the evolutionary sequence of the fossils, but the evolutionary interpretation of the fossils depends on the dating of the rocks. No wonder the evolutionary system, to outsiders, implies circular reasoning.
"The intelligent layman has long suspected circular reasoning in the use of rocks to date fossils and fossils to date rocks. The geologist has never bothered to think of a good reply, feeling the explanations are not worth the trouble as long as the work brings results. This is supposed to be hard-headed pragmatism."5
The main "result" of this system, however, is merely the widespread acceptance of evolution. It is extremely inefficient in locating oil or other economically useful deposits. Perhaps, however, geologists feel that, since biologists had already proved evolution, they are justified in assuming it in their own work. But biologists in turn have simply assumed evolution to be true.
"But the danger of circularity is still present. For most biologists the strongest reason for accepting the evolutionary hypothesis is their acceptance of some theory that entails it. There is another difficulty. The temporal ordering of biological events beyond the local section may critically involve paleontological correlation, which necessarily presupposed the non-repeatability of organic events in geologic history. There are various justifications for this assumption but for almost all contemporary paleontologists it rests upon the acceptance of the evolutionary hypothesis."6
And, as far as "ordering of biological events beyond the local section is concerned," O'Rourke reminds us again that:
"Index fossils — are regarded as the features most reliable for accurate, long-distance correlations."7
As mentioned earlier, more and more modern geologists are now recognizing the existence of circular reasoning in their geological methodologies. Among these, in addition to those already cited, is Dr. Derek Ager, current president of the British Geological Association.
"It is a problem not easily solved by the classic methods of stratigraphical paleontology, as obviously we will land ourselves immediately in an impossible circular argument if we say, firstly that a particular lithology is synchronous on the evidence of its fossils, and secondly that the fossils are synchronous on the evidence of the lithology."8
In another article, Dr. Ager, who is also Head of the Geology Department at Swansea University, notes the problem involved in trying to use minor differences in organisms (that is, what creationists would call horizontal changes, or variations) as time markers.
"We all know that many apparent evolutionary bursts are nothing more than brainstorms on the part of particular paleontologists. One splitter in a library can do far more than millions of years of genetic mutation."9
It would seem that this would lead to great uncertainty in the use of extinct marine organisms (about whose intra-specific variability while they were living we know nothing whatever) as index fossils.
Another geologist who has recognized the circularity problem is Dr. Ronald West, at Kansas State University.
"Contrary to what most scientists write, the fossil record does not support the Darwinian theory of evolution because it is this theory (there are several) which we use to interpret the fossil record. By doing so, we are guilty of circular reasoning if we then say the fossil record supports this theory."10
Still another comment on the circular reasoning process involved in developing paleontological sequences appears in an important symposium paper.
"The prime difficulty with the use of presumed ancestral-descendant sequences to express phylogeny is that biostratigraphic data are often used in conjunction with morphology in the initial evaluation of relationships, which leads to obvious circularity."11
In view of such admissions from many leading evolutionists, it is clear that there neither is, nor can be, any proof of evolution. The evidence for evolution is merely the assumption of evolution.
The most extensive recent discussion of the circular reasoning problem in evolutionary geology is the paper by O'Rourke.12 Although he attempts to explain and justify the process as being based on induction from observed field data, he does admit many important problems in this connection. With respect to the geologic column and its development, he says:
"Material bodies are finite, and no rock unit is global in extent, yet stratigraphy aims at a global classification. The particulars have to be stretched into universals somehow. Here ordinary materialism leaves off building up a system of units recognized by physical properties, to follow dialectical materialism, which starts with time units and regards the material bodies as their incomplete representatives. This is where the suspicion of circular reasoning crept in, because it seemed to the layman that the time units were abstracted from the geological column, which has been put together from rock units."13
The fiction that the geological column was actually represented by real rock units in the field has long been abandoned, of course.
"By mid-nineteenth century, the notion of 'universal' rock units had been dropped, but some stratigraphers still imagine a kind of global biozone as 'time units' that are supposed to be ubiquitous."14
Behind all such assumed time units must be the doctrinaire assumption of evolution, which is the basic component of materialism.
"The theory of dialectic materialism postulates matter as the ultimate reality, not to be questioned. — Evolution is more than a useful biologic concept: it is a natural law controlling the history of all phenomena."15
And if physical data in the field seem in any case to contradict this assumed evolutionary development, then the field data can easily be reinterpreted to correspond to evolution! This is always possible in circular reasoning.
"Structure, metamorphism, sedimentary reworking and other complications have to be considered. Radiometric dating would not have been feasible if the geologic column had not been erected first. — The axiom that no process can measure itself means that there is no absolute time, but this relic of the traditional mechanics persists in the common distinction between 'relative' and 'absolute' age."16
In this exposition, O'Rourke thus decries the common reliance on an implicit circular argument which he attributes to the assumption of dialectic materialism, and urges his colleagues to deal pragmatically with the actual stratigraphic rock units as they occur in the field, in confidence that this will eventually correlate with the global column built up gradually by similar procedures used by their predecessors.
He does recognize, however, that if the actual physical geological column is going to be used as a time scale, it is impossible to avoid circular reasoning.
"The rocks do date the fossils, but the fossils date the rocks more accurately. Stratigraphy cannot avoid this kind of reasoning if it insists on using only temporal concepts, because circularity is inherent in the derivation of time scales."17
1 J.E. O'Rourke, "Pragmatism versus Materialism in Stratigraphy," American Journal of Science, Vol. 276, January 1976, p. 51.
2 Gareth V. Nelson, "Origin and Diversification of Teleostean Fishes," Annals, New York Academy of Sciences, 1971, p. 27.
3 Donald R. Griffin, "A Possible Window on the Minds of Animals," American Scientist, Vol. 64, September-October 1976, p. 534.
4 James W. Valentine and Cathryn A. Campbell, "Genetic Regulation and the Fossil Record," American Scientist, Vol. 63, November-December 1975, p. 673.
5 J.E. O'Rourke, op cit, p. 47.
6 David G. Kitts, "Paleontology and Evolutionary Theory," Evolution, Vol. 28, September 1974, p. 466.
7 J.E. O'Rourke, op cit, p. 48.
8 Derek V. Ager, The Nature of the Stratigraphic Record (New York, John Wiley & Sons, 1973) p. 62.
9 Derek V. Ager, "The Nature of the Fossil Record," Proceedings of the Geological Association, Vol. 87, No. 2, 1976, p. 132.
10 Ronald R. West, "Paleontology and Uniformitarianism," Compass, Vol. 45, May 1968, p. 216.
11 B. Schaeffer, M.K. Hecht and N. Eldredge, "Phylogeny and Paleontology," Ch. 2 in Evolutionary Biology, Vol. 6 (edited by Th. Dobzhansky, M.K. Hecht and W.C. Steere; New York Appleton-Century-Crofts, 1972) p. 39.
12 J.E. O'Rourke, op cit, pp. 47-55.
13 Ibid, p. 49.
14 Ibid, p. 50.
15 Ibid, p. 51.
16 Ibid, p. 54.
17 Ibid, p. 53.
*Dr. Morris is Founder and President Emeritus of ICR.