Tuesday, December 9, 2008
The scientists were aboard Operation Deep Scope, a research expedition sponsored by the Ocean Exploration program of the National Oceanic and Atmospheric Administration. They explored the deep sea with a submersible vessel looking for things related to the interaction between light and life in the ocean.
They found some of what they were looking for, but that wasn’t all. There were “all these littlemudballs in the background with tracks behind them,” Matz says. “At that moment we did not have the slightest idea what they might be.”
The team posited. Snails? No? Sea urchins? Nope. Deep sea poop? Uh, no.
After taking DNA samples and matching them against a database, Matz and his colleagues identified the creature that made the tracks. It turned out to be a protist, a one-celled organism, called Gromia sphaerica.
The creatures Matz and crew found move along the ocean floor, leaving trails–the first time a single-celled organism has been shown to make such large animal-like traces.
A further finding
Matz took it another step further. He thought that the creatures and their trails could help explain trails laid down hundreds of millions of years ago and preserved in the fossil record.
Scientists have thought that multicellular creatures left those trails. Those found by Matz show they could have been made by one-celled creatures.
“If our giant protists were alive 600 million years ago and the track was fossilized, a paleontologist unearthing it today would without a shade of doubt attribute it to a kind of large, multicellular, bilaterally symmetrical animal,” Matz. “We now have to rethink the fossil record.”The creatures are grape shaped and about one-inch in diameter. They get covered with thin layer of sediment as they move along the ocean floor.
They have a thin transparent outer skin, a thin layer of protoplasm underneath it, and the inside is water. They are smooth to the touch and gives when it is squeezed.
“It’s squishy,” Matz says. “And if you squish too hard, it pops.”
He hasn’t calculated the force needed to pop it, but it does take some effort.
Matz and his colleagues, including Duke University’s Sönke Johnsen, the co-author of the paper, have followed a time-honored practice of science of making a significant discovery while looking for something else.
“Well,” Matz says, “exploration is unpredictable by definition.”
One of the most famous of looking-for-something-else discoveries was made by Arno A. Penzias and Robert W. Wilson of Bell Laboratories. They found the residual background radiation left over from the Big Bang—something they hadn’t been looking for. The discovery won them a Nobel Prize in physics in 1978.
Matz hasn’t booked a trip to Stockholm. He had a hard time finding a journal to review the findings, let alone publish them.
“I asked them, “Please send it to a paleontologist,’” he said.
Finally, Current Biology took the bait, sent the paper out for review and published it online on Nov. 20 and in its print edition Dec. 9. Since it was announced, the discovery has been written up in the New York Times and the Los Angeles Times and several science blogs.
“Perhaps surprisingly, real professional paleontologists actually seem to like these ideas,” Matz says. “In part, of course, because they enjoy having a nice new controversy. But they do agree that we provide a better-than-before explanation for certain traces and fossils which are otherwise extremely puzzling.”
Even now, after the paper and the umpteenth retelling of the story, Matz’s enthusiasm about the discovery is evident. His eyes light up and his voice quickens.
He wants to find out more about the Gromia sphaerica, but that will have to wait until at least 2010. It’s too late to get funding for a 2009 expedition.