Human Vestigial Organs: Some Contradictions in Darwinian Thinking
In my recent article on vestigial organs in man I discuss two key points: First, one of the most egregious contradictions within the present theory of evolution, and second, the recently “discovered” non-existence of a rudimentary organ that has been hailed over the last 140 in most embryology textbooks and papers as a proof of the origin of humans from lower vertebrates.
Let’s take those here in reverse order. Start with the second point: The definition of vestigial (in the original evolutionary sense) is: “Of a body part or organ: remaining in a form that is small or imperfectly developed and not able to function.” Or according to Darwin and Haeckel, a vestigial organ is a rudimentary structure that, “although morphologically present, nevertheless does not exist physiologically, in that it does not carry out any corresponding functions” (Haeckel 1866, p. 268, similarly Darwin 1872, p. 131). (For all references, see my paper.)
An Outstanding Illustration
Among these organs, the pronephros was, at least until recently, taken as an outstanding illustration for the assertion that man is “a veritable walking museum of antiquities” (Horatio Hackett Newman 1925). Contemporary Darwinians such as Donald R. Prothero (2020) heartily agree.
What is the pronephros?
Mammalian kidneys develop in three successive stages, generating three distinct excretory structures known as the pronephros, the mesonephros, and the metanephros (Fig. 1.2). The pronephros and mesonephros are vestigial structures in mammals and degenerate before birth; the metanephros is the definitive mammalian kidney. (Scott et al. 2019)
However, directly after these sentences, we read that the early stages of kidney development are required for further developmental processes (pp. 3-4):
The early stages of kidney development are required for the development of the adrenal glands and gonads that also form within the urogenital ridge. Furthermore, many of the signaling pathways and genes that play important roles in the metanephric kidney appear to play parallel roles during the development of the pronephros and mesonephros.
Nevertheless, Scott et al. assert again (in their explanation for their Fig. 1.2):
The pronephros and mesonephros are vestigial structures in mice and humans and are regressed by the time the metanephros is well developed.
Meanwhile, we read in Wikipedia (2023) about the pronephros:
The 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 is replaced by the mesonephros after 3.5 weeks.
Nevertheless, the article continuous:
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 produce the inductive signals that trigger formation of the adult kidney.
Here are several marked contradictions. The human pronephros is “vestigial,” “rudimentary,” yet “essential”? One wonders if the pronephros and mesonephros are really vestigial structures at all — in the sense of “an atavistic formation which, like a ruin, would only be of interest as a monument.” Or rather, do they in fact have important functions?
Larsen’s Human Embryology (6th Edition 2021, p. 369) states:
During embryonic development, three sets of nephric systems develop in craniocaudal succession from the intermediate mesoderm. These are called pronephros, mesonephros, and metanephros (or definitive kidneys). Formation of the pronephric kidney (i.e., pronephros) lays the foundation for induction of the metanephros. Hence, formation of a pronephros is really the start of a developmental cascade leading to the formation of the definitive kidney.
Thus, by having vital roles as inducers, the pronephros and mesonephros are crucial to the developmental cascade that leads to the formation of the permanent kidneys. They are definitely not “useless rudiments of once-functional systems.” It seems they are unquestionably not vestigial or atavistic formations, comparable to ruins in mammalian ontogeny.
In Today’s News
But wait. There is this “breaking news” on kidney development: The pronephros does not even exist in mammals: “A recent detailed analysis of human embryos 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” (Peter D. Vize 2023, p. 23).
So much for this vestigial organ in man.
As to the first point, one of the most egregious contradictions within the modern theory of evolution, I would like to encourage the reader to check the following point: The evolutionary molecular biologist and Nobel laureate François Jacob emphasized that:
In the genetic program … is written the result of all past reproductions, the collection of successes, since all traces of failures have disappeared. The genetic message, the program of the present-day organism, therefore resembles a text without an author, that a proof-reader has been correcting for more than two billion years, continually improving, refining and completing it, gradually eliminating all imperfections.
Now, can Darwinians really have both — omnipotent natural selection eliminating all imperfections and, at the same time, human beings full of superfluous rudimentary organs constituting “a veritable walking museum of antiquities”?
Let the reader decide.
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