November 17, 2021 | Jerry Bergman

Human Birth Canal Is Well Designed

Human Birth Canal Shown To Be Well Designed, Thereby
Demolishing one of the Last Few Remaining Claims of Poor Design


by Jerry Bergman, PhD

Most of the poor-design claims made by evolutionists to support their Darwinian theory have now been effectively refuted by the peer-reviewed scientific literature. A new study has just refuted one of the few remaining examples, the putative poor design of the human birth canal. Before I describe the details of the new study, a brief history of the extensive poor-design claim is in order. The new article, which is discussed below, was produced and financed by the University of Oslo in Norway. The article confidently makes the claim that

Evolutionary flaws disprove the theory of intelligent design. Evolution has produced amazing life forms, but you need look no further than to the human body to find examples of poor construction…. An obvious example of “unintelligent design” in the human body is that women have a narrow birth canal, which makes childbirth both more dangerous and more painful than in other species.[1]

The article admits that “maternal death is now a rare phenomenon in industrialized countries” then claims that “the death rate in several African countries without access to Western medicine is up to approximately 200 times higher than that of Norway.” The caveat added admits the problem is not the design of the birth canal, but a lack of the proper health care available in the undeveloped world.

To bolster their already weak claim for poor design in the human body, the authority for the article, University of Oslo professor Glenn-Peter Sætre, attempts to give another example of poor design, as if to say “not convinced yet? Here is another example”:

The evolutionary flaws do not stop there: The human body is even constructed in a way that makes it dangerous to eat! The problem is that both the food that should be heading for the stomach and the air that should be heading for the lungs, enters our body via the same channel – the pharynx. The air, the food and the water follows the same route down to the point where the pharynx splits into the windpipe (trachea) and the esophagus. The windpipe is luckily equipped with a small valve or flap – the epiglottis – that stops food from entering it, but the epiglottis sometimes closes too late. The result is that food enters your trachea, where it can cause fatal choking.[2]

It would have been a much better design, he claims, “if food and air entered the human body via completely separate channels, such as in whales.” In other words, we should have been designed with one separate opening to the outside world that is connected directly to the lungs, and another separate opening that is connected directly to the stomach. This solution is irresponsible, as I detail citing the scientific literature in my book Poor Design.[3] Two openings would create a series of problems, including the coordination required in operating two separate openings. Actually, for breathing we now have two openings to the outside world, the mouth and the nose.

Furthermore, given the number of times we swallow in a lifetime, the problem of food getting into the wrong tube and causing a problem is less than minuscule. Humans swallow in a lifetime over 16 million times and choking on food that creates a problem is comparatively rare. For example, humans on average swallow approximately 600 to 700 times each day, mostly during meal times. However, we swallow throughout the day and even while we are sleeping.[4] In the United States, the odds of dying from choking on food is less than 1 in 2,535 persons, mostly occurring among elderly persons who have other problems.

Assuming the reader is still not convinced of the poor design claim, Sætre adds that

Wisdom teeth in humans are also an example of a poor construction. They are of poor quality, and there is often not enough room for them in the jaw. And why do we have an appendix? It has no function in our digestive system, and it can easily become infected. An intelligent and professional engineer could easily have avoided these flawed constructions in the human body.

The refutation of these claims was also well-documented several decade ago.[5] The wisdom-teeth problem is primarily in western countries with soft diets.[6] In short, as one leading dental anthropologist explained:

I am a dental anthropologist and evolutionary biologist and have spent 30 years studying the teeth of living and fossil humans and countless other species. Our dental issues are not normal. …  Our fossil forebears did not have impacted wisdom teeth, and few appear to have had gum disease…. The contradiction is new and is limited largely to industrial-age and contemporary populations. It is best explained by a mismatch between today’s diets and those for which our teeth and jaws evolved.[7]

I would phrase the “mismatch” between today’s diets and those for which our teeth and jaws were originally equipped as due to their design, but otherwise I agree with Professor Unger.

It is tragic that University of Oslo Professor Glenn-Peter Sætre, a professor at a major university, is so appallingly ignorant of the peer-reviewed literature in the areas he writes about. He also claims that the poor design of the human birth canal is a result of the fact that evolution has no foresight or intelligence. Evolution, Sætre claims, is the result of mutations, but the problem with this explanation is 99 percent of all mutations are slightly harmful or deleterious. Only the very rare ones that may prove to be helpful in certain environments are selected by natural selection, thus may become more common. The problem is, as a whole, mutations cause degeneration of the genome and eventually always cause genetic catastrophe and death or extinction.

It is also unfortunate that Sætre is evidently teaching these now-long-disproven ideas to his students. He is a full Professor of Evolutionary Biology at the Department of Life Sciences at the University of Oslo. His gross incompetence or lack of knowledge in this area in amazing. Even more surprising is, in 2019, Sætre, with Mark Ravinet, published the textbook Evolutionary Genetics – Concept, Analysis and Practice, a 336-page text costing 105 dollars(!), published by Oxford University Press.

Why do humans possess a twisted birth canal?

In short, given clear design constraints, the existing birth canal is the best possible of all possible designs. Birth is more difficult in humans because we are the only mammal whose normal mode of travel is upright bipedalism. Scientists at the University of Vienna set up the issues involved:

In comparison with humans, apes have a relatively easy birth pattern that does not require rotation of the baby thanks to the longitudinally oval shape of the birth canal both at its inlet and the outlet. “For giving birth, it would be much easier to have a uniformly shaped birth canal also in our species,” says Katya Stansfield, a specialist in biomechanics. Instead, the twisted human shape requires a complex, rotational birth mechanism: The baby needs to rotate to align the longest dimension of its head with the widest dimension of each plane of the birth canal. Misalignment can lead to obstructed labor and result in health risks for both mother and baby.[8]

The authors, all evolutionists, are not trying to explain away or justify what is regarded by evolutionists as poor design. nor are they arguing for intelligent design, but rather for evolution as is also Professor Glenn-Peter Sætre. They concluded

The relatively narrow human birth canal presumably evolved as a ‘compromise’ between its abilities for parturition [childbirth], support of the inner organs, and upright walking. But not only the size of the birth canal, also its complex, ‘twisted’ shape is an evolutionary puzzle. Researchers now present new insights into why the human birth canal evolved to have this complex shape. They suggest that the longitudinally oval shape of the lower birth canal is beneficial for the stability of the pelvic floor muscles.[9]

Although the researchers present their view that birth canal construction was a result of evolution, the term design is more specific and descriptive. The research team of University of Vienna biologists and engineers focused their conclusion on the critical

support function of the pelvic floor muscles, which are suspended across the lower pelvis and also play an important role in sexual function and continence … The team carried out extensive biomechanical modelling of the pelvic floor and found that the highest deformation, stress, and strain occur in pelvic floors with a circular or transverse-oval shape, whereas a longitudinally oval elongation increases pelvic floor stability. “Our results demonstrate that the longitudinally oval lower birth canal is beneficial in terms of stability,[10]

Furthermore, the research team concluded the following:

Traditionally, it has been assumed that the transverse dimension of the human pelvis is constrained by the efficiency of upright locomotion. “We argue that the transverse elongation of the pelvic inlet [design exists]…  because of the limits on the front-to-back diameter in humans imposed by balancing upright posture, rather than by the efficiency of the bipedal locomotion,” … A longitudinally deeper inlet would require greater pelvic tilt and lumbar lordosis, which would compromise spine health and the stability of upright posture. These different requirements of the pelvic inlet and outlet likely …[the reason for] a twisted birth canal, requiring human babies to rotate during birth.[11]

In short, the existing design is required to produce the necessary support for the pelvic organs. The considerable weight of the abdominal organs, especially in pregnant and obese women must be adequately supported to allow for human normal mode of travel, which is upright bipedalism.[12]


This review has documented yet another claim of poor design is false. Unless the birth canal were located somewhere else, such as in the lower abdomen near the belly button (which would be a very problematic design), the existing arrangement is by far the best possible design given the realities of walking upright. Changing the location of the birth canal would also require altering the location of the vagina and the female sexual response to the abdomen, obviously a far less feasible design. The vast majority of births in industrial society today to healthy mothers occur without major problems. Given alternative possibilities, it is clear that the existing design is the best possible option among all other possible alternatives. Furthermore, the design modifications to facilitate birth, such as enzymes that are produced shortly before the birth process that loosens the cartilage to allow widening the birth canal, also facilitate birth, yet allow proper support when not carrying the child, and not delivering a child.

The stages of birth. From Sharp Health News,



[1] Røsjø, Bjarne. 2020. “Evolutionary flaws disprove the theory of intelligent design.” PhysOrg, May 26.

[2] Røsjø, 2020.

[3] Bergman, Jerry. 2019. The “Poor Design” Argument Against Intelligent Design Falsified. Tulsa, OK: Bartlett Publishing.

[4] Rudney, J.D., and C.J. Larson. 1995. The prediction of saliva swallowing frequency in humans from estimates of salivary flow rate and the volume of saliva swallowed. Archives of Oral Biology 40(6):507-512, June.

[5] Bergman, Jerry. 2019. Useless Organs: The Rise and Fall of the Once Major Argument for Evolution. Tulsa, OK: Bartlett Publishing.

[6] Ungar, Peter S. 2020. Why We Have So Many Problems with Our Teeth. (Signs of the Times), April.

[7] Ungar, 2020.

[8] University of Vienna. 2021. Why do humans possess a twisted birth canal? Extraordinary shape makes births more difficult, but guarantees stability. Science Daily, 29 October.

[9] University of Vienna, 2021. Emphasis added.

[10] University of Vienna, 2021. Emphasis added.

[11] University of Vienna, 2021.

[12] Stansfield, Ekaterina, Barbara Fischer, Nicole D.S. Grunstra, Maria Villa Pouca, and Philipp Mitteroecker. 2021. The evolution of pelvic canal shape and rotational birth in humans. BMC Biology 19(224), 11 October. DOI: 10.1186/s12915-021-01150-w

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 1,500 college libraries in 27 countries. So far over 80,000 copies of the 40 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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