Circular Evolutionary Arguments

Believers are frequently accused of using circular reasoning in their arguments. Regardless of whether this accusation is justified, several examples shall be presented here to illustrate that the situation is by no means better on the naturalistic side:

1. Circular Reasoning in the Field of Teleology:

Teleology refers to the fact that in biology, terms are regularly used to describe processes in nature and the capabilities of living beings that are otherwise reserved for goal-oriented and intelligent planning—even though many biologists hold the view that life is not intelligently designed.

Evolutionary theorists naturally attempt to rid themselves of this problem, yet their arguments are, in part, circular:

1.1 Martin Neukamm's Circular Argument:

In his book Evolution im Fadenkreuz des Kreationismus (Evolution in the Crosshairs of Creationism), Neukamm claims that intentional (teleological) terms arise from an anthropomorphic way of thinking, only to then declare them misleading because they are anthropomorphic. Thus, the very point to be proven is simply presupposed. He would first need to demonstrate why the anthropomorphic way of thinking is supposed to be misleading.

1.2 Kostas Kampourakis's Circular Argument:

Kampourakis distinguishes between human artifacts and biological structures. For the former, teleological language in the sense of "design" is appropriate; for the latter, he argues it is also appropriate but is the result of natural selection, not a designer.

As an example, he compares aircraft wings with bird wings. The former, he argues, were clearly constructed for the function of flying. In birds, he suggests this is not so clear-cut, as wings in some birds are not fit for flight and fulfill other functions. The current use of wings for flight is therefore the result of evolution, "because birds are not artifacts and their wings were not intentionally designed for flying. Like all organisms, birds received their characteristics through evolution and were not intelligently designed."

The circularity here lies in the fact that evolution is already presupposed as a fact for the explanation. He fails to provide concrete evidence that selection or evolution is the actual origin of wings. This is treated in more detail, including a further circular argument and source citations, in this article.

2. Circular Reasoning Regarding the Origin of Amphibious Fish:

Contrary to original expectations, amphibious fish must have emerged independently at least 33 times. From this finding, Ord and Cooke conclude that the evolutionary emergence of an amphibious lifestyle cannot be as difficult as previously assumed, since it has occurred so frequently.

In doing so, they simply presuppose an evolutionary origin as a fact without further justification, without examining whether this unexpected convergence might actually contradict an evolutionary origin — as convergence generally does.

3. Circular Reasoning in Early Diversity:

Darwin expected a gradual increase in diversity over the course of evolution. That is, the further living beings evolve away from each other, the more different they become through new characteristics. This expectation is correct if one assumes step-by-step evolution.

However, this expectation has often not been confirmed. A particularly well-known example is the Cambrian Explosion: in the Cambrian period, many different groups and body plans (Baupläne) appear suddenly and without gradual transitions. Hughes and colleagues confirmed this in an extensive study.

They found that high early diversity is the dominant pattern from the Cambrian to the present day. Diversity then decreases over time after an early maximum. This finding is thus the exact opposite of the original evolutionary expectation.

The authors offer the explanation that early high diversity is the result of the evolution of "key innovations." However, this is not a suitable explanation, as postulating key innovations does not explain where they came from or how they originated. One can only speak of accompanying phenomena here, not causes. Accompanying phenomena can never serve as a causal justification.

Furthermore, the extent of diversity is measured precisely by the number of different body plans, which from an evolutionary perspective are naturally associated with the appearance of innovations. To see the cause of the unexpectedly early diversity in these innovations constitutes a circular argument.

4. Circular Reasoning Regarding Dinosaur Body Appendages:

It has become common practice to interpret any body covering on dinosaurs as feathers or proto-feathers, even when this is often unjustified. The reason lies in the thesis that birds descended from dinosaurs. Citing simple body appendages as (independent) evidence for this thesis is circular, as their interpretation as (proto-)feathers already relies on this very thesis.

5. Circular Reasoning Regarding Rudiments:

Rudiments (vestigial structures) are alleged remnants of evolution. They are said to be degenerated and to have lost their function either entirely or partially, or to have changed function. A more detailed article on rudiments can be found here. Rudiments are cited as some of the best evidence for evolution. However, in the case of some rudiments, the arguments are circular:

5.1 The Vermiform Appendix: 

Although the lack of function in this "rudiment" has long been refuted, it is still cited as an evolutionary remnant of a previously larger part of the cecum. The interpretation as a rudiment is thus based solely on the presupposed assumption that there was a larger cecum in evolutionary history. Citing this again as evolutionary evidence is circular.

5.2 The Tailbone (Coccyx): 

The tailbone is interpreted as the remnant of a former tail. Since it also fulfills important functions, the interpretation as a rudiment arises solely from the presupposed assumption of our descent from ape-like ancestors. Just as with the appendix, it is therefore a circular argument to view the coccyx as evidence of evolution.

5.3 Protruding Canines: 

Our canine teeth are interpreted as smaller remnants of formerly larger canines. The reason lies in the observation that modern apes have larger canines and the again presupposed assumption that we descend from ape-like ancestors. To cite this as evidence of evolution is, once again, clearly a circular argument.

6. Circular Reasoning in the Proof from Similarity:

Similarities between different species are often used as evidence of common descent. However, it is well known even on the naturalistic side that similarity cannot always be attributed to common ancestry.

Based on morphological (anatomical) features, one often arrives at contradictory phylogenetic reconstructions. A portion of the similarities must therefore have arisen convergently (independently) if the contradictions are to be resolved.

How does one recognize whether a trait is homologous (due to descent) or convergent? There are no objective criteria for this. One must first reconstruct a hypothetical phylogenetic tree in order to determine what is homologous and what is convergent according to the principle of parsimony (fewest possible convergences). In this process, the classification of a trait can change with new findings.

To recognize similarities due to descent, an evolutionary course must first be presupposed. Citing these similarities again as independent evidence for that evolutionary course is a textbook circular argument.

7. Circular Reasoning in the Origin of new micro-RNA Genes:

Humans have 94 micro-RNA genes that occur only in humans. According to evolutionary theory, they must have emerged newly in humans. Since there is insufficient time for the slow emergence of 94 new genes, they represent an evolutionary problem. Evolutionary biologists suggest new micro-RNA genes could emerge in a short time through a process called "Template Switching" (TS), which is, however, beyond all probability.

Evolutionary biologists then conclude from the fact that we have many human-specific micro-RNA genes that their emergence must be easy. Consequently, new genes through TS would also pose no difficulty. This is a circular argument. It is presupposed without evidence that the emergence of new micro-RNA genes is easy, and then concluded that the emergence of new genes via TS is easy. How easy a process is should be measured by how it works, not how often it occurs.

In doing so, evolutionary biologists are employing a textbook circular argument here. A more detailed article on this can be found here.

8. Circular Reasoning in the Origin of Life:

Dr. Bruce Damer and Dr. David Deamer answer the question of whether a first cell ("chemical computer") could arise spontaneously as follows:

"Can a chemical computer emerge spontaneously on an inanimate but life-friendly planet such as the early Earth? The answer is obviously 'yes' because life took a beginning, but the process by which that happened remains a fundamental problem of biology." (Damer B & Deamer D (2020). The hot spring hypothesis for an origin of life. Astrobiology 20, doi:10.1089/ast.2019.2045.)

The natural origin of life is justified by the fact that life exists. Thus, the very thing to be proven is again presupposed — a textbook circular argument.

Conclusion:

Accusing believers of circular reasoning as a characteristic mode of argumentation is wrong, as this occurs no less frequently on the naturalistic side. Humans are fallible, and anyone can argue circularly at times—atheists just as much as believers. The well-known example "The Bible is God's word because the Bible says so" misses the point here.

No Christian who deals with the credibility of the Bible argues this way toward non-Christians. Justifying the divine inspiration of the Bible with the well-known verse "All scripture is given by inspiration of God" is only appropriate for internal faith-based topics. This mode of argumentation only works when both discussion partners share the truth of the Bible as a common foundation. Toward critics of the Bible, one must, of course, argue differently.