FEATURE ARTICLE

Burj Al Khalifa CHANDRAYEE G. BHATTACHARYA The Great Builders Humans may have built huge structures. But let us not forget to appreciate the architectural marvels of the tiny , the ever-lasting structures built by the corals, and the infrastructure building acumen of the hard working beavers.

HE Burj Al Khalifa in Dubai, United Arab Emirates, is the Great Sphinx, at Giza, Egypt. T tallest building in the world 240 feet long and 66 feet high currently. This mega-structure of 829.8 metres is a testimony to the advances in science and technology and human expertise in constructing such a mega structure of concrete, steel and glass. History abounds of instances of several such wonderful achievements at different periods of human history. The ancient Egyptians constructed the unimaginably massive pyramids. Not only Egyptians, there were many other versions of pyramids too, in various different parts of the world such as the pyramids of Sudan, Ethiopia, Western Asia, Greece, Cyprus, Italy, India, Thailand, Mexico, South America and They practised agriculture, built great was not just a large barricade to stop on some islands of the Pacifi c Ocean buildings of stone and pyramid-temples, invasion, there were Signal towers often as well. However, those of Egypt and worked with gold & copper and made built on hilltops for maximum visibility, of Central and South America are the use of a form of hieroglyphic writing with raised platforms. And at lower best known. that has now largely been deciphered by levels there were rooms for soldiers, The ‘Pyramid of the Sun’ at expert-historians. stables for and storage areas as Te otihuacan in Central Mexico, having One of the largest building well. During the period spanning around base dimensions of 220 m by 230 m in construction projects ever carried out three hundred years (as per historical a rectangular shape, rivals in size the by man was the ‘Great Wall of China’, records, from the seventh through the most widely acclaimed ‘Great Pyramid running a length of about 7,300 km, fourth century BC) some generations of Khufu’ at Giza measuring 230 m by East to West from Shan-hai Pass near of Chinese workmen toiled till death to 230 m in a square shape. Po-Hai (Gulf of Chihli) to Chia-yü Pass construct the largest wall on the Earth. Around 1500 BC the Mayans lived (in modern Kansu province of China). Another human endeavour in a vast area from Southern Mexico, This massive wall made using mud, is building exceptionally large Guatemala up to Northern Belize. bigger rocks and crushed rocks as fi llers infrastructures for the larger cause. One

40 SCIENCE REPORTER September 2017 Nutrition for these termites is Pyramid of the Sun, Mexico provided by fl agellate protozoans living anaerobically (i.e. without oxygen) in the hindgut part of termites and secreting enzymes cellulase and cellobiase, which break down cellulose into simple sugar (glucose) and acetic acid. The termites depend entirely on these gut- dwelling-protozoans for cellulose digestion. Without these microbes the termites would starve and ultimately die. However, consider the feat of these tiny ant-like creatures, which is indeed jaw-dropping. These diminutive damage wooden-structures and furniture. As you move around following the known or unknown lanes and alleys of any market place of an Indian city, no matter small or big, chances are that you such achievement is the historically very signifi cant construction work, the longest Great Wall of China canal for a very convenient water-way to connect the Mediterranean in the North and the Red Sea in the South – a marvel of civil-engineering across the Isthmus of Suez in Egypt. This world famous canal extends 163 km between Port Sa id in the North and Suez in the South. It provides the shortest maritime route between Europe and the land-masses around the Indian Ocean and Western Pacifi c Ocean. It is one of the world’s most heavily used shipping lanes. Again, between 1850 BC till 1863 a huge workforce was engaged in this construction work facing severe challenges – hundreds died in the course of this construction work. Well, we now know too well about human ingenuity and expertise in constructing massive structures. Are there any parallels in the world of creatures other than humans? Sure there are – let’s take a look at one such example – the termites.

Super Architects – Termites Have you ever seen a -mound in the wild? In many villages, towns and cities there is a constant threat of these tiny creatures for they are bestowed with some amazing symbiont-parasites, from whom their gut receives cellulose digesting enzyme called ‘cellulase’. So, they can easily Suez Canal, Egypt. digest wood.

41 SCIENCE REPORTER September 2017 Tall termite mound built by termites

might come across the sign-boards of of the earth the miners used to dig out area. Ancient African civilizations used (PCI) Pesticides Control Board of India gold from. Termites have a remarkable termites and their enormous mounds showing the ways and means to control ability, they can vertically move subsoil as a starting place for prospecting and the termite-attack. from great depths. While living in the uncovering deposits. Now, termite-mounds at some fi fth-fl oor of an apartment-building, the The termite of Northern places are massive structures made by authors witnessed in the late nineties, Australia, meridionalis, these tiny creatures using particles of the unbelievable endurance of these tiny- miraculously orient their mounds clay, silt and sand, which are stuck creatures, moving subsoil particles up in a North-South direction by sensing together with the help of their unique there through the minute passages within the Earth’s magnetic fi eld. These wedge- sticky saliva secretion from their mouth. the concrete and cement plasters of the shaped mounds, called compass mounds And thus safe passages, alleys, lanes, columns of a multistoried-building! or magnetic mounds, are generally and by-lanes are constructed within these Off late, entomologists – scientists three to four metres high, two-and- remarkably designed earthen mounds. studying – have been helping the half metres wide, and one metre thick at One mound is a dwelling-place for many miners and mining companies by using the base. The broad side of every mound millions of termites. these insects to help fi nd new gold and faces East-West. This orientation Believe it or not, their underground other mineral deposits all over the world. probably functions to regulate passages are even as deep as 70 metres. Besides the tall and impressive mounds, the ambient temperature within Surprising though in some termite hills, the smaller nondescript ones too would these structures – a sort of air- found in Central & Northern Australia, hold cues about mining prospects of an conditioning! some parts of Africa and elsewhere too, scientists found tiny fragments A dam (right) built by a beaver (left) of gold, which these tiny arthropods might have picked up from that depth

42 SCIENCE REPORTER September 2017 The Great Barrier Reef

The Great Barrier Reef, off the coast of Queensland, Australia

Inside the mounds are honeycomb- Beaver Dam massive structure extending in a roughly like structures within which they grow Here is another example of the marvelous Northwest-Southeast direction for more fungus. Other kinds of spectacular construction of a dam…this time by a than 2,000 km, with an area of some mounds are built by fungus-growing beaver. 3,50,000 square km. Each coral-reef termites found in the regions of Indo- Two species of restless rodents, has been formed over millions of years Malaya and Africa. Ants and ant- native to North America, Europe and from the skeletons and skeletal waste of like many creatures evolved their Asia, the Beavers (Castor canadensis a mass of living marine organisms, the fungus-growing ability in the course of of North America and Castor fi ber of humble Coelenterates, zillions of these gradual evolutionary transformations Eurasia) live in streams, rivers, marshes, tiny creatures. in the past millions of years. The most ponds, and shorelines of large lakes and The “bricks” in this construction widely acclaimed ones are the famous construct dams using branches, stones of ‘reef framework’ are formed by “leafcutter ants”. and mud. They construct ponds that often the calcareous remains of these tiny Another kind of mound is of cover many hectares. Beavers have short creatures known as ‘coral polyps’, the African Macrotermes speci es that legs and a stout body with a small, broad, while the “cement” of this unique ‘reef reaches a height of eight to nine meters blunt head and massive chisel-shaped framework’ that binds these remains tall and have pinnacles, chimneys and incisor teeth having orange-coloured together is formed in large part by ridges as well on their outer walls. In outer enamel. It’s quite interesting to ‘coralline algae’. The magnesium terms of architectural designs these note that the enamel of their teeth is of content in the calcite of coralline algae mounds are superb. orange colour not white. This is because is very high, which strongly cements the Here is another queer fact about iron has replaced calcium making their millions and millions of these calcareous remains. In fact there are hundreds termites. Few of us are aware that there incisor stronger than most species of of islands which are actually series of is greater biomass of termites than animals. coral atolls built up from the crowns of the mammals found on some African Another unique feature of this submerged ancient volcanic mountain Savannas. Thus, termites remove is that as they submerge in lake ranges, for example, Maldives, the and digest the majority of plant- water, folds of skin (acting like valves) Northernmost atoll of which is about originated litter out there in those close their nostrils and their stubby 600 km South-Southwest of the Indian grasslands. And consequently, termite rounded ears. The nictitating membrane mainland. colony structures, the mounds, have keeps water out and protects their eyes. So, while ascending in the elevator long been used as geochemical and This semi-aquatic broad-tailed of Burj Khalifa at Dubai, or peeping mineralogical sample media for the persistently busy rodent, having soft through a window of a jetliner to enjoy discovery of ore deposits buried under. light brown fur, noted for its habit of the spectacular view of the Great Wall Several scientists established that gnawing through the bark of trees and of China, do not forget to appreciate the accumulation patterns within termite ultimately felling them, is adept at making architectural marvels of the tiny termites, nests include biologically-essential marvelous lodges and spectacularly the ever-lasting structures built by the macronutrients such as Mg, Ca, Zn, engineered dams, popularly called corals, and the infrastructure building P and K, which are found in termite “Beaver Dams”. acumen of the hard working beavers. nests at concentrations much above those found in the adjacent soils. Thus Great Barrier Reef Ms. Chandrayee G. Bhattacharyya, B-23, Birla these massive nests are the source of The Great Barrier Reef situated off Colony, Porbandar-360576, Gujarat; Email: minerals too. the coast of Queensland, Australia is a [email protected]

43 SCIENCE REPORTER September 2017