Can a self-replicating system that requires two unique components to perform one function arise by random mutations?

Biological life began with simple cell division—one cell divides to become two cells, which divide to become four cells, etc. According to Darwin and Neo-Darwinists this simple division process evolved slowly over eons by the natural selection of random mutations to eventually create humans. But is this possible over any length of time?

The transition from cell division to sexual reproduction involves extremely complex physiology, and I contend cannot be attained by “numerous, successive, slight modifications” as Darwin requires lest his theory “absolutely breakdown.” This transition may be incalculable.

            To complete the transition let’s examine what is involved. First, all biologic and physiologic information must be present in the DNA code that sexual reproduction is producing. But the production of the single DNA code that leads to the production of one model requires two models of one species that must be physiologically distinctive yet uniquely compatible. These two distinctively unique models must arise from the same fertilization process and proceed through a complicated physiologic transformation arising from the same embryonic, fetal, and adolescent maturation processes. This means numerous specific three-dimensional molecules must be present in every cell and either inhibited or activated according to a precise plan.

            These distinct physiologic transformations reside within the urogenital system. As you can infer, the reproductive system is integrally related to the urinary system. And sexual reproduction must be viewed through both systems simultaneously. In his textbook on embryology Larson notes:

In both sexes germ cells and sex cords are present in both the cortical [superficial] and medullary [deeper] regions of the presumptive gonads, and complete mesonephric and paramesonephric ducts lie side by side. The ambisexual or indifferent phase of genital development ends at this point and, from the seventh week on the male and female systems pursue diverging pathways.[1]

            So, what causes males and females to develop differently? Obviously, this development is under genetic control as is everything else in the human body. As we all learned in high school, females have two X chromosomes, and males have an X and a Y chromosome. Genetic research has determined that a gene on the Y chromosome (SRY) is expressed in the sex cord cells at the end of the sixth week, and the male heads off on his own way. Larson describes this differentiation process:

The product of this gene, called the SRY protein, initiates a developmental cascade that leads to the formation of the testes, the male genital ducts and associated glands, the male external genitalia, and the entire constellation of male secondary sex characteristics.[2]

            This is an amazing and astonishingly complex process. In order to provide a sense of just how numerous and poorly understood some of these processes are, I present quotes that are taken from section headings or subsection headings in Larson’s embryology textbook. I have italicized terms that conceal complex processes:

  1. “Male genital development begins with the differentiation [remember, differentiation is much more complex than replication—a fact Neo-Darwinists would like you to forget] of Sertoli cells in the medullary sex cords.”[3]
  2. “Contact between the pre-sertoli cells and the germ cells regulates the development of the male gametes.”[4]
  3. “Antimullerian hormone secreted by the pre-sertoli cells controls several steps in male genital development.”[5]
  4. “SRY protein initiates a cascade that induces the differentiation of testosterone-secreting Leydig cells in the testis.”[6]
  5. “The mesonephric duct and mesonephric tubules give rise to the vas deferens and ductuli efferentes.”[7]
  6. “In the female, the perineum does not lengthen and the Labioscrotal and urethral folds do not fuse.”[8]
  7. “In both sexes, the descent of the gonad depends on a ligamentous cord called the gubernaculum. The gubernaculum condenses during the seventh week . . . The superior end of this cord attaches to the gonad . . . At the same time, a slight evagination of the peritoneum . . . develops just adjacent to the inferior root of the gubernaculum.”[9]
  8. “In the male, the inguinal canal conveys the testes to the scrotum and forms the sheath of the spermatic cord.”[10]
  9. “Finally, the processus picks up a thin layer of external oblique muscle, which well become the external spermatic fascia. In males, the processus vaginalis pushes this entire inguinal ‘sock’ out into the scrotal swelling.”[11]
  10.  “This second phase of gubernacular shortening is caused by actual reduction and regression of the gubernaculum as a result of the loss of the mucoid extracellular matrix.”[12]
  11.  “Within the first year after birth, the superior portion of the processus vaginalis is usually obliterated.”[13]

Larson, who is very knowledgeable about human embryology has this to say about the current state of knowledge on the singular subject of testicular descent, “The hormonal control of testicular descent is not completely understood. Androgens and pituitary hormones are important, but other unknown testicular factors or hormones apparently play a role, as does neural input via the genitofemoral nerve.”[14]

Darwin’s theory of evolution by natural selection and “numerous, successive, slight modifications” cannot provide any insight into how these extremely complex embryologic functions (the italicized terms in the previous quotes) operate. Sexual differentiation is the epitome of complexity in DNA programming. A conundrum exists where the reproductive system creates and is created by itself.

All the structures and steps in the operation of sexual reproduction must be present at the outset. If this is not the case, Neo-Darwinists must tell us which structures and functions could have been deleted, or how sexual reproduction could proceed with which missing structures and functions that were to come later in time.

The reproductive system seems to require foresight because it creates only one of two types of humans (male or female) per pregnancy (aside from the twin gestation), but complete reproductive function requires both types of humans (male and female). This means the system was created with the future dependency on another organism to provide the needed complimentary function to complete a singular function—the fertilization of an egg.

How does the human body accomplish this future complimentary function? Obviously, the same materials needed for the construction of a male are used to create a female. We know these as male and female analogs. The following chart is a quick and simplified summation of the male and female analogues that arise from an embryonic organ that is influenced by different DNA programming.


Paramesonephric ductAppendix testis, Prostatic utricleFallopian tubes, uterus, vagina
Mesonephric tubulesRete testisRete ovarii
Mesonephric ductEpididymisGartner’s duct
Urogenital sinusProstate, bladder, urethra, bulbourethral glandSkene’s glands, bladder, urethra, Bartholin’s gland
Labioscrotal foldsScrotumLabia majora
Urogenital foldsSpongy urethraLabia minora
Genital tuberclePenis bulb of penis, glans penis, crus of penisClitoris, vestibular bulbs, clitoral glans, clitoral crura
PrepuceForeskinClitoral hood
PeritoneumProcessus vaginalisCanal of Nuck
GubernaculumGubernaculum testisRound ligament of uterus


            In conclusion, the embryology of the urogenital system represents a preprogrammed complex critical organ system. It is information-heavy, produces a system with interdependent functionality, and possesses multiple physiologically active structures manifested by the male and female analogues. The complex system is designed, in part, for the function of reproduction but requires two physiologically distinct organisms both of which arise from a singular egg-sperm fertilization. All this structure and function must be complete and present from inception since there is no step or structure that can be absent without failure of the entire system (in my book The Collapse of Darwinism, I provide known mutations of male and female genotypes and congenital anomalies that occur when something goes wrong). I contend that it is impossible for the urogenital system to have arisen by the natural selection of random mutations, and therefore Darwin’s theory absolutely breaks down. I challenge Neo-Darwinists to describe the molecular biology and physiology that occurred by numerous, successive, slight modifications to produce a functioning urogenital system.

[1] William Larsen, Human Embryology, 3rd edition (Philadelphia: Churchill Livingstone, 2001), 277.

[2] Id., 268.

[3] Id., 279.

[4] Id., 280.

[5] Id., 282.

[6] Id.

[7] Id.

[8] Id., 288.

[9] Id.

[10] Id.

[11] Id.

[12] Id., 289.

[13] Id.,292.

[14] Id.

[15] Id., 277-288, and Alexander Sandra and William Coons, Core Concepts in Embryology (Philadelphia: Lippincott, 1997), 2.

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