Far below Romanian soil lies the Movile Cave, a chthonic environment sealed off from light and the outside world for millions of years. Jack Grove reports on a UK scientist’s descent into research heaven and arachnophobe hell
Imagine a labyrinth of caves cut off from the outside world for 5 million years, crawling with spiders, scorpions, worms and bizarre creatures never before seen by humans.
WHEN the light of day is turned off for five and a half million years, creatures trapped in perpetual darkness must learn to navigate without seeing, to live in an atmosphere that could kill outsiders and to make do without the solar energy that sustains the food chain elsewhere. But survive these troglobionts do, and a pitch-dark cave in Romania has become a laboratory for biologists studying life at the precarious edge of existence.
It sounds like the stuff of an Indiana Jones movie or the underground world of Jules Verne’s A Journey to the Centre of the Earth (1864), but the Movile Cave in southern Romania is no fantasy. Discovered in 1986, it is one of the most isolated places on Earth and has proved a fruitful area of study for scientists, who believe it could offer clues about how life itself began.
It has taken years to begin cataloging the creatures in Movile Cave for several reasons. First, it’s a dangerous environment with a poisonous atmosphere. Getting into the cave requires some familiarity with spelunking and diving, too. You have to go down a narrow 20-meter shaft, then climb through tiny limestone tunnels before reaching the main cavern. The Romanian government has also been very selective about who is permitted in the cave for fear of upsetting the delicate ecological balance. Only a few dozen scientists have been allowed to visit.
The cave has remained sealed by the authorities since its discovery, and fewer than 30 people have set foot inside the unique ecosystem. Microbiologist Rich Boden, a lecturer in environmental microbiology and biotechnology at Plymouth University, is one of them. He was the first UK scientist to enter the cave system to explore how life has flourished there without sunlight for millennia.
The real reason why Movile Cave has shocked the entire scientific world was in fact the weird ecosystem found inside. Several animal species, of which 33 were completely new, have been found in this absolutely independent bionetwork.
The novelty resides in the discovery of the first ecosystem on Earth whose life is based on chemosynthesis (life without oxygen). According to scientists, this procedure was supposed to be possible only on Mars, Europa and other planets, but never on Earth.
Among the creatures found inside the Movile Cave there were two pseudo scorpions, a 10 cm millipede whose bite is venomous and extremely dangerous, a very unusual water scorpion, four spiders and a new species of leech. All the underground residents are characterized by a pale color, total lack of vision and giant antennas used to move in the dark. It is believed that these living fossils have survived for millions of years, their refuge in the Movile Cave beginning taking place during the Ice Age. Larry Lemke, a prominent researcher at NASA whose main preoccupation is to investigate the existence of life on Mars, has compared Movile Cave’s living conditions with those on Mars.
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.
Most creatures in Movile Cave are believed to have arrived over five million years ago when limestone sealed the entrance. Most insects have since adapted to the complete darkness by losing their eyes and pigmentation. Many have also developed longer legs and antennae to feel around in the dark. The ecosystem relies entirely upon chemosynthetic bacteria that extract carbon from the air without the aid of light. The most numerous bacteria use carbon dioxide, and others get their carbon from methane. The bacterial film on the water and walls is where all the nutrients enter this ecosystem, and it’s the only known example of such a system. Small animals eat the slime, and larger animals eat them.
The organisms living in Movile Cave may help explain how some of the world’s greatest caves, including Carlsbad Caverns in New Mexico, were hollowed out of the rock. Dr. Kane believes that chemoautotrophic bacteria like those in Movile Cave may have played key roles. By oxidizing hydrogen sulfide from the water, the bacteria produce not only free sulfur but also sulfuric acid, which attacks the calcium carbonate of which limestone consists. The mixture of water and sulfuric acid produced by bacteria probably eats away the rock over the centuries, eventually hollowing out great underground chambers. If this is the case, he said, one could expect to find calcium sulfate, or gypsum, in the caves, and in fact the walls of Movile Cave are coated with gypsum.
Movile Cave was discovered accidentally in 1986 during an excavation nearby, but while the Romanian dictator Nicolae Ceausescu lived, scientists were barred from the site. After Ceausescu was overthrown in 1989, however, Serban M. Sarbu, a political refugee studying at the University of Cincinnati, returned to Romania to begin the cave research that has continued ever since.
Creationists sometimes point to complex predator-prey relationships, food chains, etc., as examples of creative design. While this is certainly feasible in many cases, even likely, it appears unlikely that the particular food chain in this case was the direct result of original creative design; at least, not created for that purpose. Rather, it probably arose as a result of each member being forced to survive on what it could, an adaptation (of an earlier ecosystem) based on necessity.