The world within a world is a tantalizing concept advocated by sci-fi and fantasy writers but so far it was in the realms of imagination. But truth can be stranger than fiction and nature takes a vicarious delight in putting the spokes in the well-ordered physical world of humans. One such spoke is the bizarre creatures of Movile cave, a chemical (chemosynthesis) world within the organic world of humans.
In the South-east Romania, close to the Black sea lies a cave beneath the earth that has remained completely cut off from the outside world for 5.5 million years.
In Constant county, Romania close to the Bulgarian border lies a bleak, unremarkable land. The plains have nothing to recommend for except for one thing – the cave beneath the land has led a cloistered existence for 5.5 million years. While Earth was evolving prodigiously with Primates descending from the trees and advancing to Homo Sapiens, the world beneath existed completely sequestered from the outer world.
The lack of sunlight has not stopped the evolution of life.
There has been a complete lack of light and thriving poisonous atmosphere in the cave. But this toxic atmosphere has helped in the creation of bizarre creatures that are never before seen by humans. There exists unique scorpions, spiders, woodlice and centipedes who owe their lives to the presence of a strange floating mat of bacteria.
The cave was discovered by Romanian scientist Cristian Lascu.
In 1986, Communist workers who were testing the feasibility of the land for a power plant stumbled across the cave by accident. Cristian Lascu was the first to make his descent into the cave. The Romanian authorities have sealed the land preventing unauthorized entry of the people. Fewer than 100 people have ever seen the interior of the cave- it’s a number comparable to the people who have gone to the moon.
The cave can be accessed by descending down a narrow shaft, climbing down through an ochre clay coated limestone tunnel in total darkness and in a temperature of 25-degree centigrade. The tunnel opens into a central cavern opening into a lake.
Microbiologist Rich Boden says that the cavern is hot and humid, smells of rotten eggs and the atmosphere contains poisonous gasses and is very low in oxygen.
In 2010, microbiologist Boden visited the cave and described it has a hot and humid place. He further adds that the sulphuric pool gives off a hydrogen sulphide when disturbed. The atmosphere is laden with poisonous gases and has a negligible amount of oxygen. Oxygen that is present (only 10% as against the normal range of 20%) is not sufficient for breathing. It can cause a headache while spending a continuous 5 to 6 hours amidst the poisonous water can harm your kidney.
Despite the lack of sunlight and the overwhelming presence of a poisonous atmosphere, the cave is teeming with life.
The cave has all sorts of creepy crawlies and slithering things. There are leeches that swim on the water to prey on the hapless earthworms. Shrimps and snails graze on the microbial mat and these grazers are prey to the deadly predators, spider, and the scorpion. Strangely, the worse the air, the greater the life forms.
A frothy, foamy microbial mat floating on the surface of the water provides nutrition to the cave dwelling life forms.
The cave doesn’t possess any nourishment in its pool nor does it have stalactites or stalagmites dripping nutrients from up above. Instead, food comes from a floating film that looks like a wet tissue paper. This ’tissue paper’ is composed of millions of bacteria known as autotrophs. These autotrophs use chemosynthesis to get their energy.
Another group of bacteria known as methanotrophs survives on methane found in the cave. They, in turn, release metabolic intermediates like methanol providing food to the other bacteria’s in the food chain. Movile is only such ecosystem on land that supports its food chain in this way.
J. Colin Murrell, a microbiologist, however, says that these bacterias are remarkably simple and there is nothing unusual.
The microbiologist says that the bacteria get its carbon from one source and are similar to bacteria found in Roman baths at Bath, the mouths of the cattle or in the human mouth and gut. Murrell says “Autotrophic bacteria of the same types we found at Movile are found in almost all soils and on the surface of the skin.”
The same cannot be said about the creatures living in the cave. Million years of sequestered existence has completely changed them.
Most of the animals do not have eyes. They have long appendages like antennae to help them feel their way around. The lack of pigmentation has led to a translucent skin. There are no flies yet the spiders spin the web to capture small insects known as springtails.
48 species of animals were found in the cave. They include leeches, spiders, scorpions, and insects.
In 1996, researchers categorised the animals. They discovered that 33 are endemic to the cave. They included a centipede, 3 species of spider, 4 species of isopod and an unusual looking creature known as water scorpion.
One of the spiders is closely related to a spider that is found in canary Islands,which lies off the north-west coast of Africa.
Theories abound about the origin of the life forms within the cave.
The presence of these unusual animals has generated various theories. One theory speculates that the climate of Northern hemisphere changed about 5.5 million years ago at the end of Miocene Epoch.The movement of Africa to the north caused the Atlantic to dry up. The freezing temperature could have forced the animals to seek shelter in the Movile Cave. The steady warmth and lack of predators or competitors may have led to the flourishing of lives in the underworld haven.
Another theory states that the animals might have arrived at various times. This theory gains credence in the light of the fact that the cave’s only snail is just over 2 million years old. when it entered the cave the ice age was beginning, the cold may have pushed the snail underground.
The Movile cave’s life forms provide valuable information on global warming and evolution of life on earth.
The bacteria’s ability to oxidise methane and carbon dioxide – both important components of greenhouse gases may offer us a precious insight in tackling the global warming.
The conditions in the cave are similar to primordial earth when life first evolved. It could be that the first living forms were similar to the animals found in the cave, thus offering valuable information about the evolution of life on earth.
Despite 30 years after its discovery, the Movile cave hangs on to its secrets. There are many more organisms’ to be identified, secrets to be revealed. Perhaps, Movile cave will help us in understanding the capricious nature of earth.