For a certain time after they are born, male and female children resemble one another. But after years, differences begin to emerge in the bodies of each. A beard appears in males, their voices deepen, their shoulders widen, and they come to have the typical features of the male body. Girls begin to take on the typical female form. Two bodies that resembled each other closely, except for the sex organs, take on quite a different appearance after the secretion of the sex hormones in adolescence.

What brings about the change in male and female bodies are the sex hormones that God has created in a highly organized manner.

The main sex hormone in the male is testosterone; in the female, they are estrogen and progesterone. When we look at the mechanisms by which these hormones are secreted, we meet a few other wonders of creation.

Sex hormones are secreted in the male testes and in the female ovaries. But the system that ensures this secretion is located very distantly from these organs, in the pituitary gland and the hypothalamus area.

Many years from the time of birth pass before the sex hormones go into action. But when the right time comes, when the child has reached the age of adolescence, the hypothalamus sends a command (the GnRH hormone) to the pituitary gland. The fact that the hypothalamus does not make a mistake in timing (unless damaged) is remarkable. How can a small piece of flesh take account of days, months and years without a calendar (or more precisely, without the conscious intelligence required to understand a calendar) and do everything with perfect timing? This fact is a proof that the hypothalamus has been designed by God in a way to properly affect this timing.

After receiving the command, the pituitary gland secretes two hormones, LH and FSH. The target areas of these hormones are the female ovaries and the male testes. These hormones give a command to these organs to "go into action" after years of being inactive.

The testes and the ovaries then begin to produce the sex cells proper to males and females and to secrete the sex hormones. The LH and FSH hormones in men and women have the same molecular structure, yet each is responsible for different processes in the male and female bodies.

In the section entitled "Hormones That Are Able to Regulate Time and Produce the Differences between the Sexes" we examined the wonder that these hormones have different effects and that they wait years to be secreted.

Now, let us examine how the male and female reproductive systems develop and see what kind of system God has created for each new human being that has come into the world.

The Female Reproductive System

Sex hormones give shape to the male and female bodies with the expertise of a sculptor.

The most important organ in the female reproductive system is the ovary, each of which weighs between 10-20 grams. The ovaries make the egg cell that is half of the newborn person. (The other half is the sperm cell that comes from the male body.)
Another function of the ovaries is to produce sex hormones. This is a very important function because these hormones make a child's body a woman. This function resembles a sculptor making a statue, but the hormones are not outside the body as the statue is outside the sculptor's body, rather, (in the case of the hormones) the statue is formed inside the body.
The sex hormones produced in the female body, for instance, cause the pelvis bones become wider because during pregnancy, it will make the needed room for the baby in the mother's womb. -Intimate Universe, British Broadcasting Corporation - The Learning Channel Co-Production Video, 1998

How do these cells that produce the female hormones know that the woman may later get pregnant? If they had this knowledge, how will they tell the cells which form the pelvis bone how much they must multiply to widen the proper amount? How do they know the right size for the pelvis bone?

Moreover, in women, the accumulation of fat in the hips and thighs is again physically the result of the influence of estrogen. In a male child, it is not fat that increases in the developmental stage, but the striated muscle mass. In women, the increase in the amount of fat is specially adjusted to store the energy that will be needed for the time of pregnancy and milk production. -Rasyonel Tedavi Yonunden Tibbi Farmakoloji (Medical Pharmacology According to Rational Treatment), p. 2751

The sex hormones cause the development of a high voice in women and low voice in men.- Rasyonel Tedavi Yonunden Tibbi Farmakoloji (Medical Pharmacology According to Rational Treatment), p. 2723- How do the hormone molecules know the difference between a male and a female voice? How is it that they can decide that a male voice has to be low and a female voice high? And how do hormones, with the same formula, produce a high voice in women and a low voice in men?

It is a demonstration of great wisdom that female hormones are not secreted until a particular age. Female hormones come into play when the female body is mentally and physically mature; that is, when the time comes when it can carry a baby, and it has the intelligence and maturity to bring it up.- Ic Hastaliklari (Internal Diseases), p. 369- This arrangement is certainly another proof that human beings have been created according to a definite plan.

A Four Week Period of Life

Every four weeks in the body of a healthy woman, a comprehensive preparation occurs. This preparation is brought about by cells in the woman's body in order to bring a new human being into the world.

Ovaries produced by female sex hormones.

As a mother considers her child's every need, its health and development and makes long-term plans for it, the cells that make up the mother's reproductive organs show the same degree of care for the egg cells. In order to ensure the fertilization of the egg cell, they carry out long-term plans, and the most important factors affecting this plan are hormones.
Just before this four-week period, the pituitary gland secretes the LH hormone. After this hormone leaves the skull, it sets out on its long journey via the blood stream and reaches the ovaries. Now the time has come for the ovaries to go into action.

Inside the ovaries are thousands of immature egg cells. Under the influence of the LH hormone from the pituitary gland, part of these egg cells begins to mature. Normally, only one of these developing cells will fully mature and be released from the ovary as an egg cell. (If two cells are released and each one is fertilized, twins will be born)
The egg cell in process of development with its surrounding nutritive layers is called a "follicle." The FSH hormone sent by the pituitary gland has a major effect on the follicle, suddenly causing it to produce a special molecule. This molecule is the estrogen hormone.
How is it that the follicle, which is itself not fully developed, has begun to produce a hormone? What is the purpose of this production? The answers to these questions bring us to another proof of creation.
The estrogen produced by the follicle shows once again the wonder of creation. Let us look briefly at its functions:
1. One of the targets of the estrogen hormone is the "uterus." This is where the fertilized egg will lodge, multiply and grow. The influence of estrogen causes the uterus to prepare for pregnancy; its wall increases 3-4 times in thickness and is surrounded by capillary vessels. If fertilization occurs, these vessels will supply the required nutrients.
This is a wonder because the still developing follicle cannot consider the future of the cell inside it, yet it takes the required measures needed for the future nutritional needs of the egg. It also ensures that preparations are made in the uterus where the egg will be protected.

After releasing the egg, how does the follicle know that it will reach the uterus and lodge there? How does it know that capillary vessels in the uterus will provide nutrients for the egg cell? From whom did it learn the formula for causing an increase in the number of capillary vessels?

2. Under the influence of estrogen, the muscles in the uterus begin to develop and their strength increases. This is a measure taken to protect the place where the egg will lodge in case of fertilization.- Rasyonel Tedavi Yonunden Tibbi Farmakoloji (Medical Pharmacology According to Rational Treatment), p. 2750

3. The growth in the women's breasts during the time of development is closely connected to the influence of estrogen. Estrogen increases the accumulation of fat in the breasts and, at the same time, ensures the multiplication of milk glands. All these preparations ensure that the baby will be fed by the mother.

4. The construction of other parts particular to a woman's body also happens as a result of the influence of estrogen. Of interest is the fact that estrogen causes growth in a woman's breasts but never goes to produce growth in the shoulder area except in extraordinary cases (which would give a woman a masculine appearance).

Estrogen also produces the high pitched woman's voice instead of a male voice. It knows what kind of voice needs to be produced and it knows how to make a woman's voice. The sculptor that forms the special features of the woman's body is "estrogen."

A sperm—the male reproductive cell.

5. At the same time, estrogen facilitates fertilization. At the end of the second week, when it is the best time to fertilize the egg, the amount of estrogen in the blood rises significantly. This results in the secretion of a special fluid from the uterus to the vagina. This fluid captures the male reproductive cells, the sperm, within itself and carries them upward. It increases the activity of the sperm and carries them towards the egg cell.

6. Unless special measures are taken, the mother's womb is a highly septic environment. This presents a serious threat to the health of the mother and the unborn baby. Estrogen ensures that this threat is eliminated. When estrogen molecules reach the epithelial cells in the mother's womb, these cells begin to secrete an acid. This acidic environment is a suitable environment for the multiplication of beneficial bacteria (Döderlein's bacillus) and, at the same time, it protects the vagina from infections.- Rasyonel Tedavi Yonunden Tibbi Farmakoloji (Medical Pharmacology According to Rational Treatment), p. 2750
The chemical molecule produced by a tiny follicle not only gives shape to a human body from head to toe, but also makes the required arrangements for a new human to be born. However, estrogen is a lifeless material that is formed from the arrangement of atoms. It is produced by unconscious cells and it affects other unconscious cells. But all of these operations happen in the context of a wonderful and flawless plan, at the end of which a boy or a girl is born. The intelligence that creates this human being belongs to God.

O mankind! Heed your Lord Who created you from a single self and created its mate from it and then disseminated many men and women from the two of them. Heed God in Whose name you make demands on one another and also in respect of your families. God watches over you continually. (Qur'an, 4: 1)

Preparations to Meet the Egg Cell

When the mature egg enters the second period of its four-week life (about 14 days later), it is released from the ovaries. Now, the egg cell begins its journey to the mother's womb. If it is fertilized during this journey, it will begin a new life; if it is not fertilized it will die and be expelled from the body.

When the egg cell leaves the ovary and starts its journey, it is still supported by the inside of the ovary it left behind and also by the pituitary gland located at a far distance from it. The pituitary gland knows that the released egg needs help and secretes a special hormone called LTH. This hormone travels by way of the blood to the ovaries and affects the mass of cells called the "corpus luteum" in the ovary, which in turn secretes progesterone.

The progesterone hormone has a special design and a very special purpose. This hormone, although it never leaves the ovaries and never sees the world outside them, influences cells located far distant from it, ensuring that these cells act according to a definite plan. This is yet another example of the wonder of creation that occurs in the human body.
When progesterone molecules reach the uterus, they cause, as in the case of the estrogen meeting the egg cell, that certain preparations are made. In one sense they increase the strength of estrogen.

Progesterone also affects the ovary itself, by preventing a new egg cell from being released. Otherwise, as an embryo was developing in the mother's womb, a second egg cell would be fertilized, producing a great danger both for the developing embryo and the mother.

The structure of an ovary where female sex hormones are produced...

How does progesterone know that, after fertilization has occurred, a second fertilization must not happen and that it is necessary to stop the activity of the ovary to prevent it? Who gave this ability to progesterone, which is only a molecule?
Another special function of progesterone is to diminish the influence of the oxytocin hormone secreted by the pituitary gland. As we saw earlier, oxytocin is a hormone that goes into effect as the time of birth approaches and ensures that the uterine muscles will contract. As a result of these contractions, the baby comes out of the mother's womb more easily.

If oxytocin affected the uterus during the first days of fertilization, these muscles would eject the fertilized egg as it attached itself to the uterine wall, and pregnancy would never occur. Progesterone goes into effect at this stage and inhibits the influence of oxytocin, preventing the fertilized egg from being ejected. Progesterone is amazingly designed to negate the effect of oxytocin.

How do the cells, which produce progesterone, know about the existence of oxitocin? Remember, progesterone is produced by cells inside the ovary. Oxytocin is produced far away from ovary, in the pituitary gland located in the skull. How did oxytocin learn what causes the uterus to contract, and that the fertilized egg could be ejected? What intelligence designed the progesterone molecule to prevent this?

A diagram showing the structure of the hormonal system in females. With the secretion of FSH and LH from the hypothalamus, the hormonal system is activated. The estrogen and progesterone secreted as a result of this causes a female to enter puberty.

The planning here demonstrates the existence of an intelligence that did the planning. And, in order for this planning to be done, this intelligence must know all the detailed aspects of the human body. God, Who has created human beings with all their special characteristics, has created an ideal harmony in the progesterone-oxytocin mechanism.

A maturated egg is ejected from the ovary in the direction of the fallopian tube (1). It advances through the fallopian tube (2-3-4), and reaches the uterus where it lodges in the uterine wall (5-6).

Progesterone has another special feature, which is still another proof of the helplessness of human beings before God Who created them.

The moment a fertilized egg cell reaches the wall of the uterus and begins to grow there, it becomes something foreign in the mother's body. The immune cells in the mother's body would inevitably attack this group of cells as they multiply. This attack would end the life of the baby even before it began and pregnancy would never occur.

But progesterone prevents the cells of the immune system from attacking the zygote in the wall of the uterus. Besides its other functions, progesterone also protects the developing group of cells from being attacked. Certainly, this shows once again that progesterone was created by a high intelligence, that is, by God.
As noted earlier, secretion of progesterone occurs in the second half of a four-week period. If fertilization does not occur in this period of time, the amount of progesterone and estrogen in the blood quickly decreases because it is no longer necessary to make preparations for a new human. These preparations (the multiplying capillary vessels to feed the fertilized egg in the wall of the uterus) are expelled from the body, a process called menstruation.

The secretion of the FSH hormone four weeks later in the pituitary gland corresponds to a new egg cell that begins to maturate in the ovary, and another new four-week preparation period starts.

The Male Reproductive System

Hormones also play a key role in the male reproductive system. About 10 years after birth, when adolescence begins, male hormones come totally into play. This happens when a chain of command is established in the body. At the top of this chain of command is the hypothalamus.

After birth, the hypothalamus secretes a hormone called LHRH every 3-4 hours, but the amount secreted is very small. About ten years later, the hypothalamus actually "understands" that the time has come to begin the shaping of the male body and begins to secrete LHRH in smaller intervals.- Ic Hastaliklari (Internal Diseases), p. 392- The LHRH hormone moves to the second link in the chain of command, the pituitary gland. As soon as the pituitary gland receives the command, it secretes another hormone called LH. This hormone gives the command to activate the male sex glands, the testes.

Why do all these functions take so long to begin and how can we explain the timing of these mechanisms? The answers to these questions are still unknown to the world of science. In any case, this system (whose secrets human beings have not been able to solve) has operated since the beginning of history in the body of every human being.

When the LH hormone reaches the testes via the bloodstream, the cells there begin to produce a hormone called testosterone. The cells that produce testosterone know the time has come for the body they occupy to pass from childhood to manhood. The chemical formula of the testosterone they produce will turn a developing child into a man.
Testosterone molecules disperse to various parts of the body and know what they must do to certain cells in these areas. Some of the functions of testosterone in forming the male body are as follows:

Testosterone molecules cause the multiplication of muscle cells. For this reason, the male body is more muscular and stronger than the female body. The increase in muscle mass gives the male body its characteristic appearance.
At the same time, testosterone molecules affect the cells in the roots of the hair, causing the beard and mustache to appear. The hairline on the forehead is drawn farther back.

Testosterone affects the vocal cords causing a male voice to be lower than that of a woman. In addition, the testosterone molecule gives the male body its ability to fertilize the female egg.

Certainly it is surprising that an unconscious molecule can do all this. This molecule knows the particularities of the male body and directs trillions of cells in the formation of this body.

Testosterone molecule is not limited to these things. Clear evidence of design can be seen in the mechanism by which this hormone exerts its influence. In order to bring about its effects, testosterone reaches the targeted tissues (the male genital organs) and enters the cells. Inside the cell, it unites with an enzyme specially created for it whereby its effects are greatly increased.

This newly formed hormone then unites with a special receptor designed specially for it. The resulting molecular combination unites with the cell's DNA and uses the information received from the DNA to bring about a new protein synthesis. This operation ensures that the distinction between male and female bodies, and their different sexual functions, will continue.
This is such a flawlessly created system that the mechanism formed from the three-fold union of testosterone-enzyme-receptor finds the place allotted to it from among the numberless data codes contained in the DNA and, on the basis of this information, ensures production. For example, for the growth of the beard, they act on the relevant regions in the DNAs of the hair root cells. To lower the voice, they act on the appropriate region in the DNAs of the vocal cord cells.

The information given here is extremely important. Testosterone (C19H28O2) is a molecule produced from carbon, hydrogen and oxygen atoms. How does this unconscious, lifeless thing know that the information it needs to perform its function is located in the DNA? Even more important, how can it find so quickly (and accurately) the few letters it is looking for from among three billion letters (enough to fill thousands of volumes of an encyclopedia) in the DNA? The hundreds of scientists, who have worked for ten years with the most advanced technology on the Human Genome Project, are only today able to map the DNA. But they still do not know which section of the DNA is related to which organs, proteins or hormones of the human body. However, estrogen (C18H24O2) and testosterone (C19H28O2) know this very well and have applied what they know without error throughout countless years in the bodies of numberless individuals.
Certainly this system is a miracle of creation that demonstrates God's artistry.

Say: "Am I to desire other than God as Lord when He is the Lord of all things?" What each self earns is for itself alone. No burden-bearer can bear another's burden. Then you will return to your Lord, and He will inform you regarding the things about which you differed.
(Qur'an, 6: 164)

Testosterone is produced by the LH hormone secreted from the pituitary gland. But the LH hormone is just as much under the control of testosterone as testosterone is under the control of LH. When the amount of testosterone in the blood increases, testosterone molecules exert pressure on the pituitary gland to cause them to cease producing LH. Only when the amount of testosterone decreases does the production of LH begins again. The LH produced activates the testes and orders extra production in order to raise the amount of testosterone.

From this we can clearly conclude that there is an exchange of information between the pituitary gland and the testes. Two unconscious glands control each other's production and cooperate to ensure the secretion of the ideal amount testosterone for the human being, and prevent any danger that might arise from the secretion of too little (or too much) testosterone. More exactly, within the two glands molecular sub-systems are placed so as to ensure their harmonious cooperation. This flawless design shows that these systems were created to fulfill a common purpose.

At the same time, the FSH hormone secreted by the pituitary gland begins the production of sperm in the testes. Sperm cells are specially designed for the fertilization of egg cells. Another example of design is that, with the beginning of adolescence, FSH is secreted and sperm starts to be produced at just the right time.

Two Different Sexes From the Same Raw Material

Male and female sex hormones have a common characteristic. The male hormone, testosterone, and the female hormones, estrogen and progesterone, are made from the same raw material, cholesterol.

A diagram of male hormonal control.

How is it that cells using the same raw material manage to form different sexes? A testis cell gives shape to the raw material that it is given and forms male characteristics; with the same raw material, an ovary makes the estrogen and progesterone that produce female characteristics. The same substance, just because of the modifications given to it by a cell, causes the growth of the beard, the widening of the shoulders, the lowering of the voice, and the production of sperm. Again the same substance, because of the different shape given to it by another cell, causes the widening of the female pelvis bone, the growth of breasts, the raising of the vocal pitch and the preparations necessary to give birth to a child.

Cells without intelligence use the same raw material to produce molecules, each with their own flawless design (and each one destined for a very different purpose).

This one example is enough to show the greatness of the intelligence manifested in these tiny cells too small to be seen by the naked eye.

It is God Who created the seven heavens and of the earth the same number, the Command descending down through all of them, so that you might know that God has power over all things and that God encompasses all things in His knowledge. (Qur'an, 65: 12)