January 23, 2024 | Jerry Bergman

Zombie Vestigial Organ Argument Arises

The case of a “poorly designed organ”
argument that was resurrected
… and then reburied!


by Jerry Bergman, PhD

Some claims made by evolutionists have been buried by counter-evidence but, because they seem like compelling arguments for evolution, they come back to life again and again. One of these so-called supportive arguments is the ‘vestigial organs’ claim. It is also called ‘useless organs’ or ‘rudimentary organs.’ They are subdivisions of the ‘poor-design’ argument.

Many organs labeled vestigial, such as the coccyx (tailbone), are acknowledged now to have a vital function in humans. Evolutionists had argued that the coccyx is a rudimentary tail (i.e., a rudiment or leftover) in modern humans. They will admit it still has minor functions in modern humans as an attachment for certain muscles, but claim it is an example of poor design.

The Origin of Specious Arguments

The vestigial organ concept was born, or at least was popularized, by Charles Darwin who called it the ‘rudimentary organ argument.’ Darwin devoted an entire chapter in an effort to support this claim—Chapter 13, in his book On the Origin of Species. This chapter, titled “Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs,” includes the claim that embryos tend to look similar in the early stages of development, and then they diverge as their organic development progresses. As a result, remnants exist which are poorly designed or vestigial.

Another Vestigial Organ Disproved

One of the latest examples of the poor-design or vestigial-organ argument being refuted was documented by Wolf-Ekkehard Lӧnnig.[1] Lönnig reviewed the evidence for the recently “discovered” non-existence of a rudimentary organ called the pronephros, a term meaning the structure that comes before the nephron during kidney evolution. The nephron is the workhorse of the kidney, functioning to separating waste materials from that which can be recycled. The pronephros was theorized to be the beginning of the evolution of the kidney which is still present in modern kidneys.

The nephron, where the separation of waste material from that which is recycled occurs. (Wikimedia Commons)

Evolutionists have created a narrative about this structure, arguing that the basic architecture of a nephron shows that it is one of the best examples of evolutionarily conserved structures in the vertebrate kingdom.[2] It served in the past, they say, as a primitive kidney early in evolution, but progressively became more vestigial as life evolved into higher forms of vertebrates.[3] It has been advertised as a classic vestigial organ: useful in our evolutionary past, but reduced to a largely useless structure now. In modern life-forms, the pronephros is a mere vestige of its former incarnation, retained by evolutionary history.

Repetition of the Myth

This pronephros vestigial-organ story has been repeated during the last century in many embryology textbooks. Even some scientific papers have used it as evidence that humans originated from lower vertebrates. The Wikipedia definition of the pronephros below repeats the evolutionary narrative:

In the human, the pronephros is a rudimentary, nonfunctional kidney that appears during the third week of development (eight-to-nine-somite stage) and regresses by the fifth week. The pronephric duct, which arises from fusion of pronephric tubular buds, persists as a remnant after pronephric tubular regression.[4]

Another reference notes that the pronephros

organ is active in adult forms of some primitive fish, like lampreys or hagfish. It is present at the embryo of more advanced fish and at the larval stage of amphibians where it plays an essential role in osmoregulation. In human beings, it is rudimentary, appears at the end of the third week (day 20) and replaced by mesonephros after 3.5 weeks. Despite this transient appearance in mammals, the pronephros is essential for the development of the adult kidneys. The duct of the mesonephros forms the Wolffian duct and ureter of the adult kidney. The embryonic kidney and its derivatives also produces the inductive signals that trigger formation of the adult kidney.[5]

The leading textbook on the kidney, considered the bible of nephrology, makes the following claim in the chapter on the evolution of the kidney:

Mammalian kidneys develop in three successive stages, generating three distinct excretory structures known as the pronephros, the mesonephros, and the metanephros. The pronephros and mesonephros are vestigial structures in mammals and degenerate before birth; the metanephros is the definitive mammalian kidney.[6]

Demise of the Vestigial Story

The latest research has totally rejected this once-common view. Questions about its existence were actually raised over five years ago:

Contemporary papers and book chapters on nephrology open with the assumption that human kidney development passes through three morphological stages: pronephros, mesonephros, and metanephros. Current knowledge of the human pronephros, however, appears to be based on only a handful of human specimens. The ongoing use of variations in the definition of a pronephros hampers the interpretation of study results.[7]

Bakker et al. performed an extensive review of the literature, and supplemented it with original research. They concluded that “the morphology and development of the renal system in chordates is confusing and the results remain inconclusive.”[8] One factor that was important in influencing the proposed pronephros theory was “the assumption that human kidney development passes through all three kidney stages. [This theory developed in] an era in which study designs were based on [Haeckel’s now disproven] theory that ontogeny recapitulates phylogeny.”[9]

The newest analysis by Vize findings “concluded, based on the Corkins et al. study,[10] that this claimed vestigial, poorly designed organ is not only not vestigial or poorly designed, but non-existent in mammals. A recent detailed analysis of human embryos based on 300 kidneys and 10,000 cells concluded “there is in fact no pronephric kidney even present in humans, or any mammal, and they are present and functional only in animals that have an aquatic life phase.”[11] Continuing investigations are planned by both Vize and Corkins et al., to add details and clarification to the conclusion that “the morphology and development of the renal system in chordates is confusing and the results remain inconclusive.”[12]

Lessons from History

The pronephros was, until recently, an outstanding example in support of the evolutionary belief that life has evolved from simple organisms into modern highly evolved organisms such as mammals. Evidence of this was the allegedly useless remnants in modern animals that were once very useful organs in our evolutionary past.

Today, having useless or less-useful structures of our past is considered evidence of our ancestry. At the Scopes Monkey Trial in 1925, University of Chicago zoologist Horatio Hackett Newman used the vestigial-organ argument to make human evolution appear scientifically verified:

There are, according to Wiedersheim, no less than 180 vestigial structures in the human body, sufficient to make of a man a veritable walking museum of antiquities.[13]

Some of these structures were included in Wiedersheim’s list of 86 vestigial organs, all of which have now been buried. Each one is now known to be necessary for life, or at least have been confirmed to have important functions in the human body. A small representative sample includes the following:

  • Adenoids
  • Appendix
  • Nipples on males
  • Nodes on ears, “Darwin’s points”
  • Parathyroid gland
  • Pineal gland
  • Pituitary gland
  • Plantaris muscle
  • Thymus
  • Toes bones III, IV, V
  • Tonsils
  • Valves in veins
  • Wisdom teeth

One could add to this list the current example, the pronephros, which was widely used as evidence for evolution for decades. Advancing knowledge has now been rejected this evolutionary narrative.


The vestigial-organ/poor-design argument has been a valuable tool for evolutionists to support their worldview. When a claimed example is shown to be not vestigial, they never give up. Instead of dropping the argument, they come up with other examples to keep the story going.

We now have over a century of claims refuted, and new ones proposed. The example reviewed above is only one more attempt to keep it alive. Like zombies, new examples are continually resurrected to support the vestigial organ concept. No doubt there will be others . . . awaiting future burial.


[1] Lӧnnig, Wolf-Ekkehard. “Human Vestigial Organs: Some Contradictions in Darwinian Thinking.” Evolution News; https://evolutionnews.org/2023/11/human-vestigial-organs-some-contradictions-in-darwinian-thinking/, 28 November 2023.

[2] Fox, Harold. “The Amphibian Pronephros.” Quarterly Review of  Biology 38(1):1–25, March 1963.

[3] Fox, 1963, p. 1.

[4] https://www.google.com/search?q=pronephros+meaning&sca_. (Emphasis added.)

[5] https://en.wikipedia.org/wiki/Pronephros.

[6] Alan, Yu, et al. Brenner &Rector’s The Kidney, 11th edition. Elsevier, New York, NY, p. 327, 2019.

[7] Bakker, B.S., et al. “The Pronephros: A Fresh Perspective.” Integrative and Comparative Biology 59(1):29-47, July 2019.

[8] Bakker, et al., 2019, p. 29.

[9] Bakker, et al., 2019, p. 33.

[10] Corkins, Mark, et al. “A comparative study of cellular diversity between the Xenopus pronephric and mouse metanephric nephron.” Kidney International 103(1):77–86, p. 23, January 2023.

[11] Vize, Peter D. “A beautiful, complex simplicity: The origins of nephron segmentation uncovered by single-cell sequencing of the pronephros.” Kidney International 103(1):23-25, p. 23, January 2023.

[12] Bakker, 2019, p. 29.

[13]  Allen, Leslie Henri. Bryan and Darrow at Dayton: The Record and Documents of the “Bible-Evolution Trial.Edited and compiled by Leslie H. Allen. Arthur Lee & Company, New York, NY,  p. 124, 1925.

Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,300 publications in 12 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.

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