The Flawless Construction That Begins with the Embryo
The development of the human body inside the mother’s womb takes place according to a blueprint, just like the construction of a building. Yet this blueprint is far more wide-ranging than any architect may be familiar with. In the same way that you need to calculate electrical wiring before plumbing in planning a building, so the systems that will constitute the infrastructure of the human body must also be considered, and growth must proceed in light of all these details.
One of these essentials is the body’s nervous system. During the emergence of this electrical facility, a huge number of details must be borne in mind, such as the neurons that form the nerve fibers extending to all parts of the body, establishment of connections between these nerve fibers and the brain, the backbone opening enough to let the spinal cord to pass through it, and for countless neurons to be organized so as to fulfill the functions of the brain.
Yet the cells themselves possess no such blueprint or project, and have no conscious engineer or architect to direct them. Nonetheless, cells know just what part of a human being to form and when to cease their activity. Embryonic cells act in a pre-programmed manner, producing their own materials, are organized within a perfect plan, and carry out the actual construction work themselves. To claim that this extraordinary planning was carried out spontaneously by unconscious collections of cells would doubtless be irrational. It is impossible for a sound structure to come out of an unregulated workshop, even if the blueprint and materials are known. This flawless design in our bodies is Allah’s, and this construction happens with His inspiration of the cells:
Does man reckon he will be left to go on unchecked? Was he not a drop of ejaculated sperm, then a blood-clot which He created and shaped, making from it both sexes, male and female? (Surat al-Qiyama: 36-39)
The Timetable of Flawless Construction
The first cell that will give rise to a brand-new human being forms when an egg cell from the mother combines with a sperm cell from the father (for details see Harun Yahya, The Miracle of Human Creation, New Delhi: Goodword Books, 2003). In the first stage of this miraculous development, cells begin to divide until they number in the millions. The cells, which initially resemble a sphere of tissue in the mother’s womb, continue dividing and coming together in specialized groups. They continue forming light-sensitive eye cells; nerve cells able to perceiving bitter, sweet, pain, heat and cold; ear cells that will detect sound vibrations, stomach and intestinal cells that will digest foodstuffs, and all the other necessary tissues and organs.
The first structure to take form in an embryo is the central nervous system. Later it develops further, giving rise to the brain and spinal cord. Only two and a half weeks after fertilization, a lengthy cavity can be seen, caused by cells moving inwards from the periphery. By the third week, this cavity closes up; forming a cylindrical tube that belongs to the nervous system. The embryo itself, meanwhile, is still less than 2 millimeters (0.078 of an inch) in length.
In the third or fourth weeks, the heart starts to beat, yet not by means of any stimuli from the brain or central nervous system. It begins beating by way of impulses from the region immediately beneath the brain itself, which will subsequently develop into the head.
Approximately one day later, two protrusions from the brain begin emerging that will later form the eyeballs. In this sense, the eyes are outward extensions of the brain.
By the thirty-fifth day, the brain’s cortex, regarded as the center of conscious thought in a human, can be seen with the naked eye. The brain slowly keeps growing, the beginning of a process that will last for years. At birth, the volume of a baby’s brain is a quarter of that of an adult. There is very definitely great foresight in this, given the narrowness of the birth canal through which the baby must pass. In the sixth month after birth, the baby’s skull has reached half its eventual size, and three quarters of it by the end of the second year.
In the fourth year, the human brain is four times the size it was at birth, in other words 1,400 cubic centimeters. It is of course impossible for a collection of cells to know how little they need to grow in order to be able to leave the mother’s body without difficulty, nor to prefigure this in such a flawless manner. Their intelligent action is just one of the signs of their acting through the inspiration of Allah, the Compassionate and Merciful.
Some 5,000 neurons a second are produced in the spinal cord, which forms during the fifth week of development in the womb.79 The brain will later form in this region. By the moment of birth, the number of neurons in the brain has reached one hundred billion.80A large part of the brain cells form during the embryo’s first five months, and each one takes its necessary place before birth. Shortly afterwards the cells, which divide at great speed, start migrating to form the extensions of the central nervous system.
Migration, of course, is an extraordinary ability for an unconscious cell. The way that a cell senses the need to move to a specific location, determines its way there without getting lost, and stops when it reaches its destination are astounding phenomena. It is impossible for a cell consisting of fat and protein to decide spontaneously to migrate, and to do so for a particular purpose. This is an indication of Allah’s dominion over us, and just one of the infinite examples of His knowledge.
It is essential that each neuron should find its target, determined for it in the nervous system. Young neurons need guides, therefore, to show them the way to go. These “guides” are special cells that stretch like cables in the spinal cord and developing brain. Each cell quickly sets out for its target organ. Neurons emerge from the site where they are produced and migrate by attaching to these guides, until they arrive at the place they set out for, and settle there. Immediately after, they establish contact with other neurons to form connections among one another.
Throughout this journey, the neurons are accompanied by trillions of support cells known as glial cells. But how do neurons know, as soon as they come into existence, that they will be setting out on such a journey? How do they realize they will need guides to find their destinations, and what kind of cooperation they must engage in? These neurons are cells made up of molecules, too small to be seen with the naked eye. They can’t possibly take their places in such a conscious manner, of their own free will. Nor is the brain the center that directs this process, because the brain of the embryo in the womb has not yet formed. The conscious behavior here clearly proves the existence of a conscious creation.
The way that some cells in the brain turn into glial cells is also miraculous. These cells are present in large numbers in the brain, and they number ten times more than the neurons. One kind of glial cell are the macrophages, cells responsible for cleaning up the remains of dead cells in the brain. Another class of glial cell constitutes a fatty layer around neurons, acting as a kind of electrical insulation. Another kind of glial cells, found everywhere and known as astrocytes because of their star-like shape, protects the neurons, acting like a kind of sponge to soak up excess toxic chemicals. When the neurons themselves are actively damaged, astrocytes work twice as hard, doubling in size and number to maintain the high levels of substances needed to repair the damage. Each one of these important tasks is carried out by cells invisible to the naked eye.
While all these activities are taking place, around 5,000 incomparably complex cells a second continue to be produced.81Structures such as DNA, RNA, ribosome, proteins and ion channels are all present, perfectly constituted, in every cell. That all these cells, multiplying at such a rapid rate, know where they have to be, what their function will be, and what features they must possess as components of a given organ, is most striking. Moreover, cells belonging to every tissue produce proteins that determine the particular character of those cells. For example, brain cells produce proteins that help transmit electricity. Another miraculous phenomenon is how a cell knows which organ it will be a part of and what kind of activity it will perform, and that it must produce proteins to meet those requirements. But only when all these details come together can perfect system actually function. Therefore, in the human body there are a great many more detailed marvels that we haven’t considered here.
By the eighth week, all the fundamental parts of the body have developed, and the embryo turns into a fetus. At this point testosterone is produced, enabling brain development to continue according to the embryo’s gender. In the following weeks, the frontal part of the brain divides into two hemispheres. In the 11th week, the rear part develops in such a way as to form the very visible cerebellum. Cavities in the brain known as ventricles eventually form an interconnected labyrinth opening to the spinal cord. Pores in this labyrinth permit a colorless fluid to travel and wash the spinal cord and the brain for the entire lifetime.
By the twentieth week, nerve connections emerge between the brain’s outer cortex and the baby’s body. Over the next five weeks, connections between the sensory system and the brain are completed.
A large increase in the substance myelin, the brain’s insulation, is observed in the first months after birth. As soon as the axons have been insulated, they begin carrying electrical signals much more efficiently. We are able to carry out a delicate movement only through the neurons in the brain working efficiently. The axons continue being insulated with myelin until the age of fifteen, or even later.
The way that such a complex nervous system and command center emerge from the union of two microscopic germ cells, the egg and sperm, is a miracle of creation. As soon as the cells emerge, they act in one direction only, in the light of the information inspired in them. It is evident that none of the events that occur during the formation of the brain and nervous system could come about by chance. A deficiency in any single phase would impair the whole system. The way neurons emerge and grow into a network is just one of the stages in the development of the brain, yet it is impossible for even a single neuron to come into existence by chance, let alone the whole brain, as evolutionists would have us believe.
Susan Greenfield describes this extraordinary state of affairs in the creation of human beings:
Clearly, the single fertilized egg is not conscious, so when would consciousness suddenly intervene? And how can a fetus be conscious? Another idea might be that the baby becomes conscious precisely as it is born. So is it the act of birth itself that evokes consciousness? It seems hard to accept this line of thought as the brain itself is completely unaffected by the birth process . . . On the one hand, there are very specific questions to be resolved, such as how a neuron knows when to alight from its glial monorail to the correct region of brain, and how it recognizes similar neurons with which it will team up into. On the other hand, there are more general puzzles that remain complete enigmas. At what stage does individuality creep into the developing brain? How does the collection of circuits of neurons give rise not just to an individual brain but an individual consciousness? What might a fetus be conscious of?82
It is our omniscient Lord Who creates the neurons with all their properties, Who gives them the correct form at the correct moment, and installs them where they are to go. Everyone—whether they reflect on this or not—was created by going through the stages here outlined in general terms. Before the body was even aware of itself, all the necessary systems were created within it. In addition, they had no responsibility to function as an ordered system. This perfect order in our bodies is just one of the innumerable examples of our Lord’s mercy on us. The miracle of human creation is revealed in these terms in the Qur’an:
We created man from the purest kind of clay; then made him a drop in a secure receptacle; then formed the drop into a clot and formed the clot into a lump and formed the lump into bones and clothed the bones in flesh; and then brought him into being as another creature. Blessed be Allah, the Best of Creators! (Surat al-Muminun: 12-14)
Do you then disbelieve in Him Who created you from dust, then from a drop of sperm, and then formed you as a man? He is, however, Allah, my Lord, and I will not associate anyone with my Lord. (Surat al-Kahf: 37-38)
The Miracle in Cell Migration
Among cells’ most important abilities are those of growth, variation and multiplication. There is an electrical charge around every cell membrane, which acts from inside the cell to the outside, and many of the stages in cell division are stimulated electrically.
During the course of development in the mother’s body, millions of cells must assume their predetermined places. To that end, the cells journey to the target destinations set out for them in the embryo. The timing is just as important as the destinations. A positional error of just 1/100 of a millimeter (0,000,393inch), or an error in timing of just 1/100 of a second could lead to organs forming in the wrong place. The system functions perfectly, however, so that no error is ever made.
The cells make a long journey inside the embryo following a special path. Upon reaching their destination, they recognize it and stop. In other words, billions of cells know beforehand the routes they need to take and their destinations, and decide to halt when they reach the places where they belong. There is never any confusion in all this. For example, stomach cells and liver cells never become mixed up, nor do the perfectly functioning internal organs. In this way, the initial embryo slowly assumes human form. Not the slightest irregularity or disorder emerges during this entire process.
Here, the migrating cells and those they will adhere to at their destination literally recognize one another. It has been observed that as the nervous system develops, billions of neurons try to locate their partners so as to attach to one another. They also combine together in a perfect design to determine the final form and structure of the organs they constitute. For example, brain cells establish around 120 trillion electrical connections to permit the necessary communications between them. It is not hard to imagine the consequence of a single connection error or short circuit in a system of such perfection.
It is impossible for unconscious cells, lacking the ability to think and plan, to act in harmony with one another and cooperate with such immaculate calculation. It is Allah, the Sovereign of all, Who shows these cells the path they must follow and ensures that every one reaches its destination.
What! Are they in doubt about the meeting with their Lord? What! Does He not encompass all things? (Surah Fussilat: 54)