Organic substances in the soil go through oxidative decomposition depending on factors such as temperature, air, humidity, and pH balance. This is a slow burning (oxidation) event of organic substances. However, oxidative decay is hindered if one of the aforementioned factors is lacking. Then, a slow decay of organic materials in soil called humification takes place.

Humification occurs in an open system in contact with air. For example, early chemical processes start with leaves changing color in autumn. The break down and partial ingestion of leaves by soil organisms follows. During this time, water soluble carbohydrates and proteins leave the leaf tissue. What remains behind are plant structures like cellulose and lignin, which are not broken down yet. Since leaf shapes are not completely deformed, species identification can still be possible at this stage. In the decay step, however, the cellulose and lignin are decomposed by various fungi species and converted to humus.

Humic substances and their properties

Humic substances are intermediate products that occur as the result of organic materials going through a series of chemical reactions. These intermediate products are humic acid, fulvic acid, and humate. Their molecular weights are around 1.000-10.000 gr/mol, 10.000-100.000 gr/mol, and 100.000-10.000.000 gr/mol, respectively. Humic acids contain weak aliphatic (carbon chains) and aromatic (carbon rings) organic acids that are soluble in water when it has a base medium but insoluble under acidic conditions.

Fulvic acids with smaller size molecular structures can reach plant roots, branches, and leaves easily because they are soluble in water under all pH conditions (acidic, neutral, and basic). Thus, trace elements such as iron, zinc, copper, manganese, and boron can be easily transported to plant tissues via fulvic acid.

Humates, however, are insoluble in water. Only the portion of a humate called ulmic acid can dissolve in alcohol.

Major functions have been assigned to humic matter in the nutrient and carbon cycle, as they are inseparable members of the ecosystem. Plants capture significantly more nutrients from humic matter than from clay minerals. Even though they can be depleted from soil by certain agricultural practices in less than 50 years, they can still remain in natural soils, outside human activity, for hundreds or even thousands of years without being degraded. This very long presence in soil enables them to continue their functions longer. According to radiocarbon dating, humates can last approximately 1140 years; and humic acid and fulvic acid last for 1235 and 870 years, respectively, in natural soils.

Positively charged nutritious elements (cations) remain in the soil by binding to negatively charged (anions) in humic matter. Because this bond is weak, useful elements for the plant can easily be exchanged with another cation, becoming free and getting absorbed by the plant. On the other side, cations such as iron, copper, zinc, magnesium, manganese, and calcium, which are hazardous to plants when taken excessively, are held in the soil, bound to humic matter and thus not causing toxicity.

Another significant feature of humic and fulvic acid is their ability to form water bridges. Water bridges facilitate the movement of nutrient ions towards roots via soil solutions.

Aside from agriculture, humic matter, with its aforementioned properties, serve humankind in the industrial, environmental, and biomedical fields.

Industrial and environmental applications

Humic matter is utilized in the staining of leather works, as wood lining paint (natural blue color), as well as water based stripping material for furniture stains. Humic matter is also used in the production of durable, resistant papers in the paper industry, to provide mechanical strength to processed ceramics, and as an additive. It is also applied as a coloring, hardening, and plasticizing agent in plastic fabrication.

Humic and fulvic acids gain significance regarding their ability to form water soluble substances with many metal compounds containing radioactive elements in their structure.

In environmental chemistry, the main role of the humic matter is to remove toxic substances, human sourced organic chemical matter, and other pollutants from water. Calcium humate, obtained from humic matter, can bind and remove nickel, iron, cadmium, and copper in addition to radioactive elements produced at nuclear power plants from water.

Humus based filters are designed to treat sewage water and mud waste. Oils, stains, poisonous phenolic substances, and pesticides are removed from sewage via these materials. In poultry, humic substances are employed to absorb and eliminate the odor of waste gases.

Biomedical applications

Drugs for the treatment of human and animal diseases are developed from humic matter. These can be used for the treatment of viral and bacterial illnesses, in the prevention of blood clots, to cure infections, and to remedy estrogen deficiencies. Clinical studies have shown that common viral diseases of children’s respiratory tracks can be treated with fulvic acid supplements. A lot of medical research has shown that humic matter, especially fulvic acids, have the ability to provide protection against cancer causing viruses. In a study, laboratory mice were given ethanol to trigger gastritis and it was determined that humic acids supplied to mice led to a significant reduction in the harm gastritis caused. The fact that humic acids can form compounds with heavy metals, such as cadmium, enables the excretion of heavy metals from organisms.

In our universe there is no place for waste. Once every particle completes its task, it is returned in a different fashion to be assigned another job. Humification is a good example to this reassignment as a complex recycling event in the soil. It is amazing to observe everything being generated from one thing and everything converted into one thing so easily and in such a crafty, balanced, and organized fashion. In fact, the power and wisdom behind the conversion of the remains of millions of different organisms into a few similar substances to be employed in different tasks are no less amazing.

Some people might see me as a rough piece of flesh that wiggles in the mouth. Of course I am not that simple! By looking at my color, some experienced doctors can even diagnose an illness. For example, some well-known symptoms that I show are whitening due to fever, becoming dark brown when you have typhoid, blackening because of a yeast infection, or having a smooth surface because of anemia or lack of niacin (a B-group vitamin).

If you are wondering what my primary duties are, I can say that the first is to help to produce speech, an ability which distinguishes you human beings from animals. For sure this speech production is not only mine. First of all the brain, which is the coordinator of all the organs including me, regulates all my movements in speaking. The other organs that help me form sounds to make words are your teeth, lips, palate, the vocal cords in your throat, and your lungs, which work like an air pump and vibrate those cords. As you see, so many of us work together just to produce your speech.

Other than the speech function, my second major duty is to work as an inspector to taste and process the countless fruits and delicious foods that are given by God. That is how you get an idea about an animal- or plant-based substance that you want to eat. If I did not exist, you might die because of a poisonous plant that you ate out of hunger. Many poisonous substances have a bitter taste. Indeed, I can sense their bad taste the moment I touch them and warn you to spit out the thing in your mouth immediately. When you eat sweet and delicious things, however, I make you remember and thank God, who has given them to you. However, you should be careful about my fondness for taste and control yourself since that is part of a God-given test. My Creator has made a relation between my love of taste and the evil-commanding side of your soul. He has also made me a step for your spiritual development. If you eat and drink too much, which means you are misled by your evil-commanding side and abuse my sense of taste, it will be you who lose. I do what my duty requires and get the taste of everything. But it is your job to use your will power and not to be defeated by your evil-commanding self (nafs). I will never stop you, whether you eat one piece of baklava or ten; I will get the taste of every piece. Do not ever blame me for that!

I have another function that many people are not aware of. My movement causes a negative pressure in the cavity of the mouth. Are you wondering what this negative pressure does? This pressure is needed especially for babies to nurse on their mothers’ breast easily; I help them in the sucking movement. In addition to that, as everybody knows, I have very important functions in chewing and swallowing food. I manipulate the food in your mouth; I soften and moisten it with saliva so that it can be easily swallowed. Also, during swallowing, I move the food back toward the pharynx. I have to be very careful while doing all this, since at my smallest mistake, your teeth might bite and hurt me.

Of course, I can do all this only with the help of my Creator, who has built my anatomy of delicate tissues and cells. Since He never does anything absurd or useless, He has given every organ qualities that are both esthetic and functional. My main body consists of seventeen muscles, eight of which are in pairs. They extend in all directions. Among those muscles are the lipid membrane and some salivary glands. I am the most flexible organ in your body. My many strong muscles enable me to move in lots of directions easily. Those muscles are covered by an epithelial lining which is called the mucous membrane. The small projections on my upper surface are called papillae. These papillae are of several types. They contain receptors which allow you to sense taste and the salivary glands that help me stay wet all the time. The papillae cover as far as an A-shaped line towards my back which makes up a third of my length. Here at my back, there are plenty of salivary glands and the lymphoid tissue, also known as the lingual tonsil. Many germs that enter through your mouth get trapped here. The papillae are named according to their shapes. The filiform papillae (which are long and thin) do not contain taste buds. They only provide a rough surface to move the food easily. The food is moistened by your saliva and crushed by your teeth. Then, with the help of these papillae, I help to shape the food into smaller pieces to make it easier to swallow. The fungiform papillae are mushroom-shaped and scattered among the filiform papillae. They are located at the center of my top surface and they contain taste buds. The circumvallate papillae lie along the A-shaped line which makes up the border of my back. These papillae are larger in size and smaller in number; there are around thirteen of them. Each taste bud on the fungiform papillae has 50 to 75 receptor cells which live for only seven to ten days. When cells die because of hot or acidic foods, new ones are created to make new nerves for the taste buds. Only substances that are dissolved in water can reach the taste receptors. That is why I cannot taste a dry substance that you have taken into your mouth right away; it has to be moistened and softened first. Tasting occurs in the receptor cells of taste, where some analyses are undertaken much more delicately than in a chemistry laboratory. My receptor cells change this chemical stimulus into an electrical stimulus and send it to your brain. This electrical stimulus allows the sense of taste to be perceived.

Among the many kinds of taste, there are four major groups. The taste buds for sweetness are located near my front; the taste buds for saltiness are scattered widely on my surface; the taste buds for bitterness are found at my back; and the taste buds for sourness are on my sides.

My under surface extends between my tip and the floor of your mouth. The mucous membrane that covers this surface is smooth and does not contain papillae. It is purple in color because of the many blood vessels that are inside me and nourish me. By the way, the famous saying that “the tongue does not have a bone” is wrong, since I do have a bone. However, this bone is not located in my front body, which is why I am very flexible and I can say whatever you command me to say. But by my muscles and ligaments I am firmly bound to a U-shaped bone (the hyoid bone) at my root. I am connected to your lower jaw by this bone.

I can have disorders, like every other organ. In fact, many disorders in me are an indication of disorders in the other organs or of a metabolic illness. For example, mouth ulcers can often be seen on me. Some types of mouth ulcer are caused by stress, lack of sleep, or lack of vitamins. Others occur as a result of absorption disorders and as a symptom of Behcet’s syndrome. Some ulcers can last for weeks and they can be very painful. You might suffer from this pain especially when you speak and eat. Diseases such as syphilis and herpes also show themselves as ulcers on me. I might even become cancerous in people who smoke or in those who eat and drink things that are too hot. I sometimes show the symptoms of some metabolic disorders like Down’s Syndrome, the blockage of lymph vessels, glycogenosis and amiloidosis. In these disorders, my muscle mass shows excessive growth due to abnormally deposited glycogen and amyloid.

Dear Peter, until now, your “speechless organs” have talked about themselves in their own tongue. I have always talked, but I have always talked on your behalf, expressing your thoughts and feelings. It is you who are responsible for what I have said, good or bad, since I am bound to your will power. However, today I spoke in my own tongue, and on behalf of our Creator. As is well known, I am an organ that has great potential for both evil and good. It is your duty to control me and use me well. Do not ever forget that I am not a simple mass of muscle, epithelium and nerves. Rather, I am a tool that can be used for both debasing and elevating you. From now on, when you eat an apple, do not swallow it before chewing well; wait till I get the flavor of it very well. In that way, you will have an opportunity to thank God for the food you are given. He is the One who not only gave you that apple, but also me, the organ that can taste it. This is just another amazing thing that makes your life beautiful! By thanking God, you will deepen your worship of Him.

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir, Turkey.

Qur’anic Perspective

At this point it would be interesting to look at what Ali Unal has to say as to why no past civilization could resist decadence and time’s corrosive power. His approach refers more to the individual and free will, rather than visible causes:1

. . . [C]ontrary to the fatalism of all other philosophies, including even Ibn Khaldun’s, the Qur’an stresses the individual’s free choice and moral conduct. Although the Divine Will, as emphasized in the Qur’an, could be regarded in some respects as the counterpart of Hegel’s Geist or as other philosophies’ absolute and irresistible laws of history, the Qur’an never denies human free will

. . . . Ibn Khaldun, Toynbee, Spengler, and other philosophers of history formed a mistaken conception of history because they did not try to discover the real dynamics of historical movements. Rather, they sought to explain the apparent causes behind a civilization’s establishment, flourishing, and decay. Whoever looks to the past will arrive at the same conclusions. But just because no community has remained at its peak this does not mean that this is an inevitable end or a determinist grip on the fate of each nation. Past civilizations collapsed because they did not heed the warnings of what had happened to earlier peoples. Accepting historical determinism causes us to nullify free will and consider the warnings and advice found in the Divine Scriptures and social sciences as useless and absurd.

This is strongly confirmed by the Qur’an in the following verses:

. . . surely God does not change the condition of a people until they change their own condition. (Rad 13:11)

. . . God never changes the grace He has bestowed on any people until they first change that which is in their hearts. (Anfal 8:53)

Theories concerning the collapse of civilizations

There are many theories concerning the collapse of civilizations, but of course, if a theory does not conform to reality, it is worth nothing. In this article, I will first give a brief account of widely held beliefs about the collapse of civilizations, explain the weaknesses of these theories, and then give a rationale that I believe better explains the historical data we have. As for most social problems, we will perhaps never know the truth about why societies collapse. However, the stakes at hand are so high that we must make every effort to understand, and to an extent, solve this problem.

The most common explanation for such collapses is some insurmountable natural disaster, like an epidemic, hurricane, drought, or earthquake that leads to the demise of a civilization by killing the population and crippling the economy. Widely-cited examples are the eruption of the volcano in Thera that preceded the collapse of the Minoan civilization, the malaria epidemic in the Roman Empire or earthquakes in Mesoamerican societies. These arguments, which are very appealing to our human nature, that desires simple explanations for all questions, are in fact very unsound. Societies constantly experience such disasters, yet survive them. The potato blight in Ireland in 1845 halved the island’s population but there was no cease of sociopolitical complexity as a result of the disaster. It is strange to think that the Roman Empire, which survived many disasters before, including the eruption of Pompei in AD 79, fell to malaria. We should consider that complex civilizations are designed to absorb such disasters, and they do. Just recalling the constant earthquakes in Japan added to the loss of a world war with two nuclear bombs exploding in the heart of two large cities will sufficiently prove this notion. Japanese civilization did not collapse. On the contrary, it is one of the strongest economies in today’s international arena. It is peculiar then that some civilizations are no longer able to fight such disasters. However, an act of God can certainly collectively destroy any civilization, as it did in the past like Sodom and Gomorrah. This is clearly narrated in the divine scriptures.

The other common explanations for such collapses are intruders and competition with other civilizations. The barbarian tribes, which brought the end of Rome in the fifth century, and the Mongolians that invaded Baghdad in the thirteenth century are clear examples of the intruder argument. This argument suffers from the realization that civilizations are attacked by outsiders throughout their existence, yet for some reason they cannot defend themselves near the time of their collapse. Competition with other societies however, is in principle expected to lead to growth and expansion instead of collapse. There is no end to the examples from this category too, like the competition of the Ottoman Empire with Persia, which indirectly weakened its western front. But the competition argument is both intuitively confusing and it fails to account for major cases, like the fall of the Roman Empire.

Another widely held belief about such collapses is that at a certain point in the life of a civilization a resource is depleted and the civilization that depends on this resource is prone to collapse. The Romans and the Ottomans both depended on military expansion for their economy, and when the relatively weak nations around them were engulfed or when they were barred from further expansion by geographical limitations, such as seas or large mountains, they were no longer able to use this resource. There seems to be some truth and lessons in this argument. To the uninformed, it is a very curious fact that the cradle of civilization was Mesopotamia, where modern day Iraq is. How is it possible that the superpowers of that era, the Sumerians (~3000 BC) and the Babylonians (~1000 BC) chose to live in these deserts? How is it possible that they irrigated the land, raised armies, and built world wonders in these sand dunes? These questions actually are easily answered when we realize that Mesopotamia was not a dessert in that era after all. It is now a generally accepted theory that this place had a fragile ecosystem, which was destroyed after thousands of years of environmental pressure. The potential for these lands to accommodate great civilizations was lost after this fragile ecosystem was slowly destroyed by its inhabitants.

However, the argument of resource depletion inherently asserts that the elite of a civilization facing resource depletion passively waits for the predictable demise. I will argue below that this case, although strange, is true. Another difficulty of the resource depletion argument is that in some instances of collapse resources were never depleted. The fertile lands of Mesopotamia still remained green until later than 1000 AD, while many civilizations experienced collapses. The Romans, who used irrigation as a resource, kept farming till the very end. Finally, one may wonder why societies aim at possessing a higher amount of resources all the time. Population increase is only a partial answer to this question. We can easily imagine a society whose population stays the same; it is not a far-fetched hypothesis that this society will naturally also try to increase its resources to fend off a variety of calamities it may experience, such as intruders and catastrophes. I believe herein lies an interesting rationale that brings together the mentioned theories that are flawed. To understand this, we first have to appreciate a law in economics, called the “law of diminishing returns.”

It is very rare in economics and in general social sciences that some series of observations can be identified as a “law.” However, the “law of diminishing returns,” first put forward in 1965 by Ester Boserup, is so comprehensive in its nature and explains such a variety of trends that it is now universally accepted. It goes: The return for an investment in a particular activity is great at the beginning, and then it gradually decreases. At a point, further investment brings no further benefits. At this point, the facility (a person, a group, a society, a factory) can no longer increase its returns, however much they would invest in that activity.

A simple example will clarify the law. Suppose we have a piece of land that we want to use for irrigation. In the beginning, we would just disperse seeds and wait for the crops to grow. Notice that our investment is minimal (say 1 unit of investment), and we get some food for our investment (again define this to be 1 unit of return). Then, if we want to increase the amount of crops we have, we may dig some canals for watering. It is straightforward to recognize that the canal digging is a lot harder than just dispersing seeds (say 5 times harder). However, it is again straightforward to recognize that although now we make 6 times more investment, we probably will not get 6 times the crop. Nevertheless, we want to maximize our return, so we still dig the canals. The next step would be to use motorized vehicles, which is maybe a 10 times increase in investment, but everybody will surely accept that it is not possible to get a crop that is 16 times greater than our original from the same plot of land. (Readers who may object that once the investments of canals and vehicles are made they will provide constant returns are reminded of the maintenance costs of these investments.) A further increase in returns may require genetically engineered crops that will require years of expensive research (more investment). The return per investment will always decrease for a certain type of activity, in this case irrigation.

This law is everywhere in life: If one week of studying suffices a result of 80 on one exam, in order to get 90, you need to study two more weeks. Most healthy people can run 100m in 20 seconds; to run it in 10 seconds you need years of exercising. Depending on one’s abilities (which determine an individual’s possible investment) these may even be impossible for many people. A vivid example is the heating problem in England during the nineteenth century. Heating, which was primarily carried out by burning wood from forests, with the increase in population had to be switched over to the burning of coal. The mining and distribution of coal, which is much more difficult than simply getting some wood from a nearby forest, was made even more difficult when the easily mined surface coal was rapidly depleted and deeper tunnels with lighting and airing problems had to be developed. It is intuitive why this law is in effect: Obviously, always, the easier solutions are adapted first, then the harder ones. Mining coal when you have easily available and plentiful wood is not reasonable. Consequently, we have a decline for our returns per investment.

The resources that civilizations use are no exception. A civilization that uses irrigation as a resource is bound to be limited by a certain level of return. Resource does not have to be depleted; it just cannot produce a return more than at a certain level. Another civilization that is dependent on taxation, mercenary or military expansion can achieve no more return after a certain level, no matter what adjustments it makes to its existing policy. Having said this, we can understand why a civilization that depends on a certain type of energy or resource cannot expand its influence beyond a certain level. Moreover, when energy becomes scarce, the civilization can become less agile in terms of trying new resources and new ways to produce returns, since agility and innovation mostly depend on using some of the surplus resources on strategies that will most probably yield no returns. Hence the rise of large architectural structures and many inefficient military operations are carried out during the ascent of a young civilization. These activities, which are easily buffered by the large returns that come from initial investment on the main resource of a civilization become impossibly costly later when the returns from the same investment is declining.

One last piece of the puzzle completes the rationale as to why civilizations collapse, and this piece is an easily accepted assumption: A civilization is like a dinosaur. It is large and strong, but it is adapted to the conditions into which it was born. The conditions change, however, the dinosaur cannot change its behavior. It helplessly tries to maximize the returns for the type of resource that it is adapted to use, and after a point, it simply cannot, thanks to the universal and unforgiving law of diminishing returns. At this point, another civilization, that primarily uses another superior resource, will have larger returns, build a larger army to invade the former civilization, build larger ships to cut off the trade routes, and produce goods to cripple its economy… This is just a matter of time, and it is unavoidable (see Figure 1b). The strength of the civilization in its golden age is now its weakness. In such a weakness, since there is no extra resource to fight new problems-all resource is either used up by the population, or goes toward defense costs-even a natural disaster can bring an end to a civilization that once seemed to be indestructible.

The Ottoman Empire’s strength in its rise was its perfect hierarchical organization which led to the accumulation of all power under the Sultan. Its main resource was military expansion and taxation of trade. These adaptations, which were ideal for the time between the thirteenth and fifteenth centuries, led to one of the most powerful empires that have ever reigned. However, by the sixteenth century, these strategies had become burdens: Due to the strong hierarchy, an intelligentsia that supported science and art as in the West could never develop. Military expansion had to stop. Taxation could no longer work since the Mediterranean Sea was no longer used for trade. The strategies were not abandoned though, instead, more investments were made in order to increase the returns, which as we saw above is a nonviable alternative. Eventually, other civilizations that used better resources brought about the end of the Empire. A similar order of events can be observed for other civilizations that collapsed. The great Arab historian Ibn Khaldun of the fourteenth century likens the lives of civilizations to the natural lifespan of individuals. They are born, they grow old, and they die. In my view, a civilization does not die because it gets old; it dies because it cannot compete with a stronger civilization.

The natural question to ask is if our current civilization will collapse. From the analysis above, we can conclude that there are two reasons for the collapse of a civilization: 1) Dependence on a certain type of investment and failing to adapt to the new conditions. 2) The invention by another competitor civilization of a new type of investment with higher returns. In today’s world, both of these reasons are in some ways different than those that existed in the past. First, with the advancement of science, the current civilizations are flexible in the resources they utilize, the options are constantly evaluated, the heating in United Kingdom does not collapse when wood is depleted; instead, coal, then gas, then nuclear power is used. The return for the investment made for some utility is similar to the curve shown in Figure 1c: whenever the return for a type of investment declines, we can shift to the next resource. Second, by the immense advancement in information processing and communication, the whole world is aware of the types of investments other societies are using, and a leading civilization that follows the developments in other countries is very unlikely to be threatened by a sudden development in a rival civilization. Third, because of progress in international trade, the old sense that any other civilization is an enemy has lost its significance.

Notwithstanding these reasons, only a few decades ago, at the height of the cold war, we witnessed the possibility of the immediate collapse of our civilization. Global warming and the depletion of petrol reserves were only two of the many alarming cues that we may have turned to declining returns for our investment curve. It is imperative to remember again that the stakes are very high. The next civilization to fall may bring about the fall of the human species.

Notes

1. Tainter, J. (1988). The Collapse of Complex Societies, Cambridge University Press, Cambridge: 1988.
2. Grigg D. Ester Boserup’s theory of agrarian change: a critical review. Prog Hum Geogr. 1979; 3 (1): 64-84.
3. Unal, Ali, Islam Addresses Contemporary Issues, Kaynak, Izmir:1998, p. 142.