Hey, who's he callin' primitive?!
Posted on 03/30/2005 9:44:09 AM PST by PatrickHenry
Deep beneath the oceans of the world, in the cold and dark where sunlight never penetrates, scientists are discovering that deep clefts in half-molten rock are teeming with life -- vast populations of primitive microscopic organisms that thrive on the intense heat, obtain their energy from chemicals alone, and provide food for other creatures higher up the sea's food chain.
Down there, great slabs of the Earth's crust are heaving and splitting apart. Viscous rock thrusts up from the mantle beneath to create networks of conduits where seawater circulates at brutally hot temperatures.
In some places, undersea volcanoes spurt lava onto the sea floor from the crests of long ridges that mark the crustal gaps, or "spreading centers" as they're called. Scientists have only recently found that hillsides in the abyss miles from the spreading centers also vent volcanic heat -- and harbor wide varieties of microbes.
Elsewhere on the ocean bottom, where volcanism plays no role, other chemical and geologic processes produce hot-water vents that countless generations of primitive microorganisms may have called home for billions of years.
The most fascinating of the microbes are known as archaea, a class that can thrive in the most extreme of temperatures and that is believed to be the most primitive of all living things -- perhaps the very first living organisms on Earth. Archaean fossils have been found in ancient landforms that some scientists date as far back as 3.8 billion years ago, which means that they may have appeared barely a billion years after the planet was formed.
Those organisms, the scientists believe, may provide clues to the kinds of life that might once have existed on Mars, when that planet could have been warm and wet and hospitable, or on Europa, the intriguing moon of Jupiter, whose thick ice crust covers a vast ocean where the deep waters could be heated by radioactive elements near the planet's core.
Rachel Haymon, a marine geologist at the University of California, Santa Barbara, and her colleagues have been exploring the hydrothermal vents of a long chain of mid-ocean ridges called the East Pacific Rise for more than a decade. Heat-loving microbes there, called hyperthermophiles, can resist temperatures as high as 750 degrees Fahrenheit at the small, "black smoker" volcanoes.
Diving in the deep submersible Alvin, Haymon and her husband, marine geophysicist Ken C. Macdonald, have discovered that the tall, "abyssal hills" on the flanks of the ridge also spurt high-temperature water -- triggered by bursts of seismic activity -- and spew masses of microbial life from rocks as old as a million years.
The submerged midocean ridges snake around the entire globe for more than 40,000 miles. According to Haymon, the abyssal hills her team is exploring are the dominant landforms of the entire planet. She and Macdonald have explored only two sites so far aboard Alvin, both of which lie about 25 miles from the axis of their ridge line on the East Pacific Rise, and they hope to find many more on future dives.
From the evidence they have found, and in a report they published in the current issue of the journal Geology, they are convinced that the hills hold an entire world of life just beneath the sea floor in the crust's uppermost layer. They have already discovered some of that life.
Using Alvin's long suction tube that they call their "slurp gun," Haymon recalled in an interview last week, she and Macdonald were sucking up one patch of what looked like mud from the hot rock one day when Macdonald looked closely and cried out, "Hey, it's alive!"
And indeed it was: a waving mat of organisms, all stuck close together like the nap on a quality carpet.
Back in their laboratory, Christopher Ehrhardt, a graduate student on the team, has analyzed the living "mud," sequenced its DNA, and discovered no fewer than four different orders of archaea -- which in turn must include uncountable numbers of different species.
"What if all those ridge flanks hold an entire biosphere beneath their surfaces?" Haymon wondered. "We're rich in speculation, but we think those processes have been going on forever, and they may well have been where the earliest forms of life emerged on the planet billions of years ago -- and perhaps on other planets too."
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Hey, who's he callin' primitive?!
Thanks for the ping!
fascinated bump.
Good read.
Seems that we know less about our ocean depths than we do the moon.
Typical or not, please stop.
read later
Use a Jacques Cousteau voice when reading it.
Gawd...sumpin' about the title of this post I find very erotic and intriguing. That does it! I'm gonna go get a life!
You may be Aquaman, But I'm AquaVelva Man!
LOL. I'm old enough to remember that, too :)
Christianity and Evolution are not at odds. Why the Orthodox, Catholic and Lutherin churches accept physical evolution.
Very cool information
We're rich in speculation...we think those processes have been going on forever...
Any word when they will move from giddy unbounded speculation to application of the scientific method?
...were sucking up one patch of what looked like mud from the hot rock...
I guess it's good that these things don't get mad easily.
This superdeep ocean life thriving on thermal processes is one of the most fascinating scientific discoveries of the past ten years. Thanks for posting this article.
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