They take hold when common ones slip up

Jan 12, 2010 09:42 GMT  ·  By
The Lost City chimney Poseidon, shown with a wreckfish, rises 60 meters above the seafloor
2 photos
   The Lost City chimney Poseidon, shown with a wreckfish, rises 60 meters above the seafloor

Hydrothermal vents are some of the most peculiar structures in the world today, in the sense that they are the last places you'd expect to find life in. However, this is almost always the case. Naturally, no larger, more complex creature could withstand the heat and the harsh chemicals that are emitted from the oceanic crust, but microbes thrive in this environment. In fact, they even create complex structures that can reach towering heights. Inside these mega-colonies, countless types of the microorganisms, some common, and some more exotic, live together.

In a new scientific research, it has been demonstrated that the most uncommon type of microbes, which tends to be found very rare, can grow at times to form the majority of some colonies. Experts believe that this is possible only because these small organisms wait for the opportune moment to strike, and exploit any mistakes made by other, more conventional types. The investigation was conducted at the Lost City hydrothermal vent field, which is the only structure of its type to have ever been found. It is located at the bottom of the Atlantic Ocean, near the rift that separates the floor in two. Through the rift, new oceanic crust is continuously generated, pushing Europe and Africa away from the Americas.

In a new scientific paper published in this week's issue of the respected journal Proceedings of the National Academy of Sciences (PNAS), researchers from the Marine Biological Laboratory, in Woods Hole, Massachusetts, detail how these shifts in the ecosystems take place. Their work was funded by the US National Science Foundation (NSF)'s Division of Ocean Sciences. The group investigated closely the chimney Poseidon, which is a feature of the Lost City that rises more than 60 meters above the ocean floor. The structure is estimated to be about 1,000 years old, and is made up of microbes that can only be found in small numbers in other colonies.

According to the investigators, it could be that these microorganisms managed to get hold of the supremacy when the hydrothermal vent cooled. This change brought about another in the ecosystem, and the rarer organisms adapted better to the new conditions. This allowed them to thrive, and overtake the common varieties in numbers, thus producing their own chimney. “A fundamental prediction of the 'rare biosphere' model is that when environmental conditions change, some of these rare, preadapted microbes can rapidly exploit the new conditions, increase in abundance, and out-compete the once abundant organisms adapted to past conditions,” University of Washington (UW) postdoctoral researcher William Brazelton, an author of the new paper, says.

“The rare biosphere of the Lost City microbial community represents a large repository of genetic memory created during a long history of past environmental changes. The rare organisms were able to rapidly exploit the new niches as they arose because they had been previously selected for the same conditions in the past,” the authors conclude in the journal entry.

Photo Gallery (2 Images)

The Lost City chimney Poseidon, shown with a wreckfish, rises 60 meters above the seafloor
An underwater spire: the top few feet of an actively venting carbonate chimney at Lost City
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