Spider Silks

Ibrahim B. Syed, Ph. D. 
President
Islamic Research Foundation International, Inc.
7102 W. Shefford Lane
Louisville, KY 40242-6462, USA
E-mail: IRFI@INAME.COM
Website:  http://WWW.IRFI.ORG

Those who read the Noble Qur’an must be wondering why Surah, 29 is titled “Al-Ankabut.” or the Spider which is a lowly insect.  
 

This article explores the human reasoning as to why Allah (SWT) chose Al-Ankabut as the title of Surah number 29 and the word Ankabut is mentioned in Ayah (verse) number 41 of Surah 29 as follow: 
 

“The parable of those who take

Protectors other than Allah is that of the Spider

Who builds (to itself) a house;

But truly the flimsiest of houses is the Spider’s house

If they but knew.” 
 

People consider spiders are nuisances or horrifying creatures that should be exterminated whenever possible. In fact spiders are benefactors of humans. Every year spiders do away with millions upon millions of insects such as locusts and grasshoppers that would destroy grain crops, and with such consumers of green leave as beetles and caterpillars, as well as with troublesome mosquitoes and flies. One authority stated in the following words: "If it were not for the number of spiders everywhere, all living creatures except defoliating (leaf-eating) caterpillars might face starvation." 
 

Spiders keep control of the insects without using the man-made insecticides, which are posing many environmental problems including the decreasing of sperms in the human male thus resulting in infertility. Therefore we must appreciate our spider friends which are performing this service with no ill effects whatever to mankind. They exist in abundance and they are found almost anywhere. Some types flourish indoors, and others live outdoors but close to the buildings. In the fields they make their homes on tall plants and low shrubs, in forests they take refuge under dried leaves and fallen logs. Any piece of bark or stone may serve as a spider shelter. We may find them near water and even on it, in dry country, in underground caves, and on mountaintops. Because of ignorance, through the ages, in countless stories, spiders have been connected with sinister, unhealthy activities and places. They are treated as sinister and aggressive and usually capable of a deadly bite. 
 

The truth is a spider is a mild creature, most anxious to avoid contact with man. It bites only when hurt or frightened, and usually will walk over a person's skin without making any effort to bite. In fact the majority of spiders we come across are small and because their biting apparatus is not strong enough, they are not capable of breaking through the skin of a human being. One must be aware that a large wolf spider will cause no greater pain nor inconvenience from poison than a wasp usually inflicts. On the other hand a black widow, the only spider native to the United States which can inflict poisoning of a truly serious nature upon humans, is small-no more than half-an-inch in length. Because of this the black widow is always given wide publicity. Black widow poisoning is often serious, but rarely is it fatal. Very young children and adults who are not in good physical condition suffer from it most acutely. If treated properly and promptly the ill effects usually lessen in a few hours and after a couple of days rest, the victim has completely recovered. 
 

SPIDER SILK  
 

The strength of spider silk, so delicate in appearance, is surprisingly great. A strand can be stretched as much as one half its normal length before breaking, and has a tensile strength surpassed only by fused quartz fibers. Fine strands are stronger than others, the strength to some extent depending on the speed with which they are drawn out of the spider's body. The greater the speed, the greater the strength. There are other variations, too. Most of the silken threads are not single fibers but are made up of two or more strands. A fiber may be as fine as a millionth of an inch in thickness but more often it is ten or twenty times as thick, and the grouping of these fibers naturally produces threads of a variety of thicknesses. Also some fibers are sticky while others are not.

Making a web is one of the many uses to which the spider puts silk to use. Spiders uses the silk for trap lines, draglines, ballooning lines, for trap-door covers to underground retreats, for egg sacs and nursery webs, for chambers in which to hibernate or to mate, for the many types of webs in which food is ensnared, and for entangling and swathing their prey. Silk for all these purposes is not achieved with one type of gland; there are at least seven different types that equip the whole spider group. Some individual spiders have as many as six kinds and possibly have more than six hundred separate glands; others have less than this. 

ANALYSIS OF SILK  
 

The silk itself is a substance known as "scleroprotein." When produced in the glands it is a liquid; only when drawn outside the body does it harden into thread. Once it was thought that exposure to the air caused the hardening, but it now appears that the drawing-out process alone is responsible. To carry forward the work done by the glands, a spider is equipped with spinnerets, usually six in number. These are as flexible as fingers; they can be extended, compressed, and in general be used like human hands. In the "spinning field," where the spinnerets are grouped, single threads are combined into various thicknesses, and some of the dry strands may be coated with a sticky substance. Thus a finished strand may be thin or thick, dry or sticky. It may also have the form of a beaded necklace. For the latter type the spider spins rather slowly and, pulling out the sticky thread, lets it go with a jerk. The fluid thus is arranged in globules spaced along the finished line. The thread known as the dragline may be thought of as a spider's "life line" for it acts as a lifesaver under all sorts of conditions. No matter where or how far a spider travels, the dragline goes along, reeling out from spinnerets at the rear of the body. It forms part of the construction of webs, it holds its little manufacturer securely in difficult places, and it aids in escaping from enemies. For a spider resting in a web the dragline makes possible quick drop and hideout in vegetation. It enables active hunting spiders to leap from buildings, cliffs, or any high point incomplete safety. 
 

BENEFITS OF SPIDER SILK TO MAN  
 

One may be wondering why the spider silk in contrast to the silk of the silkworm, is not of great commercial importance. One reason lies in the varying thickness of spider thread. Also it is more difficult to work with, and, because it does not stand up well in the weaving process, it lacks the luster of insect silk. Besides all this the problems of housing and feeding large numbers of spiders are great compared with supporting silkworms. 

Primitive people like in New Guinea have used spider silk in a number of ways. They make fishing nets and lures and such articles as bags, headdresses that will keep off the rain, and caps. These are not fashioned from single strands but from matted, twisted threads. The primitive natives of North Queensland, Australia, look to spiders for their fishing equipment. One way they use them is to entangle one end of a thin switch in a web, then, using a weaving motion, they twist the coarse silk lines into a single strand which may be more than a foot long. The strand of silk is then trailed through the same area. As a fish rises to this bait its teeth become entangled in the invisible strands of silk and it is easily pulled out of the water. Most fish caught in this matter are no more than two inches long, but it is claimed that such silken fishing poles can hold more than half a pound of weight. 

Besides being helpful to primitive people, spider silk has proved useful to the makers of such complicated instruments as astronomical telescopes, guns and engineers' levels. The fibers, being very fine yet strong and able to withstand extremes of weather, are excellent for sighting marks. During the Second World War there was considerable demand for spider fiber for surveying and laboratory instruments. The silk would be reeled from the spinnerets of living spiders, then stored on especially constructed frames until needed. Black widow spiders were used to a great extent for this silk production, although the common house orb weavers, the gardens orb weavers and others all help to provide the silk employed for specialized purposes. One draw back to the use of spider silk in industry is its ability to sag in a humid atmosphere. For this reason filaments of platinum or engraving on glass plates take its place in such instruments as periscopes and bombsights.

FIBER ENGINEERING

As we know the orb-weaving spider produces one of the world’s toughest fibers. Using recombinant DNA technology, DuPont scientists in the United States have created synthetic spider silk as a model for a new generation of advanced materials. It has been suggested that a single strand of spider silk, thick as a pencil, could stop a 747 Jumbo Jet in flight. Whatever comparison one uses, the dragline silk of the orb-weaving spider is an impressive material. On an equal weight basis, it is stronger than steel. In addition, spider silk is very elastic. It is this combination of strength and stretch that makes the energy-to-break of spider silk so high. Simply put, it is the toughest material known. Spider silk is merely the most dramatic example of a sizable family of biopolymers possessing a combination of properties that synthetic materials cannot yet approach. Researchers at DuPont are looking to these natural materials as paradigms for the design and synthesis of a new generation of advanced structural materials.

SECRETS OF SPIDER SILK 

It is very important to learn exactly how the spider makes its silk because this knowledge can serve as the basis for a new generation of materials. Fundamental to achieving these materials is the ability to control all aspects of the material architecture, beginning at the molecular level. Recombinant DNA technology provides a practical route to harnessing the power of the biosynthetic process to control polymer sequence and chain length to a degree that is otherwise impossible. A broad range of mechanical properties is accessible by careful selection of the appropriate building blocks, as more sophisticated properties that are common among proteins. Advanced computer simulation techniques to design a molecular model that integrates all the information available to date about the structure of this amazingly strong and elastic fiber. Synthetic genes were designed to encode alleges of the silk proteins. These genes were inserted into yeast and bacteria and the protein analogs were produced. The biosilk was then dissolved in a solvent and the protein was spun into fibbers using spinning techniques similar to those of the spider. 

REVOLUTION THROUGH SYNTHETIC SPIDER SILK 

Scientists are envisioning many possible uses for biosilk. Textile applications are an obvious one. The elasticity and strength of existing products such as spandex and nylon have to be improved. Because it is lightweight, tough and elastic, biosilk may also have applications in satellites and aircraft. More importantly, the new generation of advanced materials that spider silk research may bring about has the potential to transform our lives in countless ways we can scarcely imagine. It has been over 52 years since the discoveries of Wallace and Carothers and his team that gave the world nylon and ushered in the age of polymers. Initial successes predict that harnessing biosynthesis will play a major role in the new materials revolution. Synthetic spider silk may help create super-performing garments of the future. Earthquake resistant suspension bridges hung from cables of synthetic spider silk fibers may someday be a reality.

(An ancient Greek legend says a young girl named Arachne was an excellent spinner and wove the most beautiful cloth. She challenged the goddess Athena to a contest. When Athena saw Arachne’s beautiful work, she tore apart the cloth and beat the young girl. Disgraced, Arachne hanged herself. Athena repented and changed Arachne into a spider with a magic liquid, so that she could spin forever and ever. The scientific name for the class of animals to which spiders belong is Arachnida-named after the young girl in the famous Greek legend). 

WHY SPIDER’S HOUSE IS FLIMSIEST OF HOUSES? 

Every Muslim reader of this article has a problem understanding this article because according to the Noble Qur'an (Surah 29, Ayah 41) cited above the FLIMSIEST of houses is the spider’s house. The scientific studies show that a single strand of spider silk, thick as a pencil, could stop a 747 Jumbo Jet in flight, and that on an equal basis, the spider’s silk is STRONGER THAN STEEL. All these sound too far-fetched and incomprehensible and extremely difficult to understand the mysteries of science. But most important of all this article apparently CONTRADICTS the verse 41 in Surah 41. 

The quick answer is that per unit weight the dragline silk of the golden orb spider is one of the world’s toughest fibers. Webs are combinations of many kinds of spider silk all able to be produced by the same spider. The web radials are strong, but the somewhat weaker circumferential (quasi-circular concentric) fibers are elastic and sticky-to absorb the energy of a flying insect and hold it in place. Silk fibers for victim and offspring encapsulation (cocoons) are also different. The strongest of all is the fiber, which the spider uses for transport, the dragline silk. In summary the spider produces both strong and as well as weak fibers and the web it weaves to catch flying insects is weaker and hence it is referred to in the Qur’an as the FLIMSIEST of houses. 

Muslim scientists and researchers throughout the world should get inspiration from the Qur’anic Ayat and pursue research in areas that benefit not only Muslims but also the whole of humanity. Biosilk is one such area, which needs to be explored by young Muslim scientists and research workers in the Muslim World. 

[Dr. Ibrahim B. Syed is considered to be the foremost exponent in the world for the interpretation of the Noble Qur’an in the light of modern knowledge. Ed]