The Interesting Features of Plants
The ability to measure time is an ability that one does not usually expect to see in other living things other than man. It may be thought that this is limited to man, but both plants and animals possess a time-measuring mechanism, or "biological clock."
The Biological Clock in Plants
In the 1920s, when two scientists in Germany, Erwin Buenning and Kurt Stem, were studying the movement of bean plant leaves, they saw that the plants were moving their leaves towards the sun throughout the day, and that at night they were gathering their leaves vertically upwards and assuming a sleeping position.
Some 200 years before these two scientists published their findings, the French astronomer Jacques d'Ortuous de Marian had also observed that plants possessed such a regular sleep rhythm. Experiments in a dark environment where temperature and moisture were controlled showed that this situation did not change, and that plants possessed systems inside themselves which measure time.
Under natural conditions, plants select certain times for certain activities. They do this in line with certain changes in the sunlight. Because their internal clocks are tuned to sunlight, they complete their rhythmic activities in 24 hours. In other cases, there are some rhythms which are much longer than 24 hours.55
No matter how long the rhythmic motions last, there is one point that does not change. These motions happen to ensure the life of the plant and the survival of the generations, and always take place at the most appropriate time. And in order for them to be successful, several complicated processes have to be completed in a flawless manner.
For example, in most plants flowers open at a particular time of year, i.e. at the best possible time. Plants' clocks, which regulate this time, also calculate the duration of sunlight falling on the leaves. Every plant's biological clock calculates this period in accordance with the plant's particular features. No matter what the calculation, the flowers open at the most appropriate time. As a result of research into the regulation of time in the soya bean, it was seen that, at whatever time these plants are sown, they open their flowers at the same time of year.
Plants use this perfect sense of timing in many of their functions, not just opening flowers. For example, it causes the time the poppy flower disperses its pollen to coincide with the days and hours when pollinators are most prevalent. And these days and hours vary from plant to plant. But at the end of the day, with this time regulation, every plant disperses its pollen in a manner guaranteed to give the best results. Poppy flowers disperse their pollen in July and August between 05:30 and 10:00 in the morning. That is the time is that bees and other insects emerge to look for food. At this point the flower has to include in its calculation not just its own characteristics, but also those of other living things, down to the finest detail. The plant must have accurate knowledge of the time when the creatures which will fertilize it emerge, the length of the journey they will undertake, and the times they feed. In such a situation the following question comes to mind: Where in the plant is this clock, which possesses all this "information," which does all the necessary calculations, analyses the features of other creatures, and works in a way reminiscent of a computer centre? Scientists believe that biological clocks in living things other than plants generally come into existence as an effect of the pituitary gland. But where the perfect time measuring system is in plants is still a mystery to them.
This clearly indicates a superior intelligence and power which establishes and controls the timing of all plants' different activities. God shows us proofs of His creation with His superior power and infinite intelligence everywhere, and expects us to draw conclusions from them.
Defence Strategies in Plants
Plants also have to defend themselves from their enemies in certain ways. This defence varies with the species. For example, some plants give off diverse secretions against parasites and insects and fight their enemies that way. They display a wide variety of strategies in using these poisonous chemical secretions, which is their number one weapon. For example, toadstools and cucumbers have poisonous tips, and these go into operation at the moment of attack. Another example of this fully equipped war is found in plane trees. With the help of a special liquid which it exudes from its leaves, the plane tree systematically poisons the soil under its trunk, so much so that not even the smallest blade of grass can grow in it. Although it contains this poisonous material within its own body, the plane tree itself is not harmed by it.
Plants, which have no legs to carry them away if they are attacked and no organs to fight with, have many defence mechanisms which respond to their enemies other than their secretions. There is even the ability to communicate within these mechanisms. Some plants give off a secretion from the place where they are bitten, harming an insect's digestive system or giving it a false feeling of fullness. At the same time, the leaf gives off a kind of acid, known as jasmonic acid from the damaged part, thus warning other leaves so that they can be on the defensive.
To defend themselves, corn and bean plants use parasitic wasps just like mercenaries. When a caterpillar visits their leaves, these plants draw wasps to the spot by giving off a special secretion. The wasps then leave their larvae on the caterpillars which have attacked the plant. The growing larvae then cause the death of the caterpillar, thus rescueing the plant. Some plants contain allelochemicals, that is, toxis compounds in their structures. These have effects which are sometimes attractive to animals and insects, sometimes frightening, sometimes causing allergic reactions, and sometimes lethal.
For example, butterflies avoid plants of the group cruciferae (the mustards) cannot approach heather plants, because their flowers contain a toxic substance called sinigrin in their defence mechanisms. For this reason, butterflies forage avidly among the umbelliferae, because they know that these do not carry poison. How butterflies could have learned to distinguish between them is also a question awaiting an answer. It is impossible for the butterfly to have learned this from experience. Tasting the plant could mean the butterfly's death. In that case, the butterfly must come by this information in some other way.
Maples', and particularly sugar maples', defence planning for the protection of their leaves and shoots from harmful living creatures is usually much more effective than the insecticides human beings produce. Although the sugar maple has very sugary water in its trunk, it sends a substance called "tannin" to its leaves. This is a substance which makes insects ill. Insects, having eaten the leaves containing tannin, go up to the uppermost leaves, which contain less tannin, to escape. But the uppermost leaves are where birds go most. The insects which flee there are then hunted by birds. Thanks to this strategy, the sugar maple is saved from the depredations of insects with little harm done.56
The passion vine of Central and South America, is an ideal kind of food and most attractive to the caterpillars of the black, yellow and red heliconius butterfly. An adult female always lays her eggs on this particular vine, so that as soon as her offspring hatch they can start feeding on this delicious food. But here there is a very important point to be made. These butterflies check the leaves of the plant very carefully before laying their eggs. If she finds eggs like hers already deposited on the vine, then they do not select that place, but go in search of another plant, for there may not be enough food.57
Insects' preference lying in that direction is quite a big advantage, because the passion vine takes advantage of the insects' choosy nature to protect itself from attack.
Some types of vine plant form little green nodules on the upper parts of their leaves. Other species develop little marks in colours resembling butterfly eggs on the bottom parts of the leaves, where they meet the branch. Caterpillars and butterflies which see this think that other insects have laid their eggs before them and abandon the plant without laying their eggs on it, and begin looking for new leaves.
The vine plant, which protects its leaves by such an unbelievable method, is a plant which emerges from the soil everyone knows and consists of a dry branch and leaves. The plant possesses no intelligence, memory, or identification skills. It is totally impossible for it to know the features, preferences, and egg shape of an insect, a creature completely different to it. But as we have seen, the hanging plant knows under what circumstances an insect will abandon laying its eggs and head off for another plant; furthermore, it creates patterns which resemble those eggs on its own leaves, and makes a number of changes. Let us think, what a vine plant has to do to imitate the eggs of any insect. Imitation is a skill requiring intelligence. So the plant must have intelligence, it must see and understand these eggs and store them in its memory. Then it must develop a defence mechanism by combining various artistic abilities with these features, bringing about certain changes in its own body. Not one of these things, of course, can be brought about by the plant itself, nor as the result of various coincidences. The truth is that the hanging plant was "created" in possession of this characteristic. This is a defence system specially given to it by God. God, who plans everything down to the finest detail, has met the needs of all plants in the world wherever they are found. God is the ruler of everything. He knows everything that goes on in the universe. God states this truth in a verse:
He directs the whole affair from heaven to earth. (Surat as-Sajda: 5)
A Few Examples of Interesting Plants
When the arum lily is ready for fertilization, it begins to emit a sharp-smelling ammoniac gas (NH3). The flower has a most interesting structure. The region where the pollen lies is inside and at the bottom of a white-leafed structure, and is invisible from the outside. For this reason it is not enough just to give off a scent to attract insects' attention. When the pollen is ready for fertilization, as well as giving off a scent, the lily also warms up the outer part of the flower. This scent and warming, which only happen on one day, and in the hours of daylight, are very attractive to insects. Scientists, trying to discover how this warming and scent come about, discovered that an acid emerges as the result of a speeding up of the plant's metabolism. This substance, known as glutanamic acid, creates the warming and scent given off by the plant as the result of its being broken down by chemical processes.
The passion flower, with its interesting beauty, can fight off caterpillars, its enemies, by virtue of tiny needles on the surface of its leaves. These needles enter the body of newly hatched caterpillars at the slightest change in position. In this way the passiflora flower takes precautions against any harm from caterpillars, even before they are born!59
Some beautiful things in the environment become visible in the most striking way. Snowbells, protected in winter by being frozen under a layer of snow, open their flowers in the spring when the snow melts. This carnival of beauty and colour emerging from the snow is just one example of the perfection and splendour of God's creation.
Mimosa pudica (sensitive plant) has a very interesting defence system. When the tip of the leaflets of the plant are gently squeezed, within a few seconds they collapse alongside the leaf stalks, and even the stalks themselves eventually droop into a relaxed position. If whatever is troubling the leafy part of the plant persists, it makes a second movement downwards, which exposes the sharp thorns on the stems. This is enough to see insects off. The mechanism that brings about this reaction in the plant is triggered by minute electric currents, similar to those that pass along the nerves in the human body. The plant's reaction is not as fast as ours. The electric signals, transmitted along the ducts that carry its sap, can travel 30 centimetres in one or two seconds. The warmer the temperature, the quicker the reaction will be. The base of each leaflet, where it joins the stem, is greatly swollen. The cells within are filled tight with liquid. When the signal arrives, those in the lower half of the swelling immediately discharge their water which is equally swiftly taken up by those in the upper half. And the leaf collapses downwards. Thus, as the signal travels along the stem, the leaflets fold up one after the other like a line of falling dominoes. After a defensive move of this kind, the plant pumps up its cells, and it takes 20 minutes for the leaves to open again.61
Footnotes55. John King, Reaching for The Sun, 1997, Cambridge University Press, Cambridge, p.97
56. Bilim ve Teknik Dergisi (Science and Technology Journal), March 1993, p.226
57. David Attenborough, The Private Life of Plants, Princeton University Press, Princeton, New Jersey, p.66
58. David Attenborough, The Private Life of Plants, Princeton University Press, Princeton, New Jersey, p.133-137
59. Dr. Herbert Reisigh, The World of Flowers, The Viking Press, New York, 1965, p.94
60. Michael Scott, The Young Oxford Book of Ecology, Oxford University Press, 1995, p.95
61. Malcolm Wilkins, Plantwatching, New York, Facts on File Publications, 1988, p. 141-142