Imagine a form of life so unusual that we cannot figure out how it dies. That’s exactly what researchers are finding beneath the floor of the sea off Peru. The microbes being studied there — single-celled organisms called Archaea — live in time frames that can perhaps best be described as geological. Consider: A bacterium like Escherichia Coli divides and reproduces every twenty minutes or so. But the microbes in the so-called Peruvian Margin take hundreds or thousands of years to divide.
“In essence, these microbes are almost, practically dead by our normal standards,” says Christopher H. House (Penn State). “They metabolize a little, but not much.”
House goes on to discuss what a slow metabolism may imply about environments outside our own planet. Imagine hydrothermal vents on Europa, where the energy ration may be slim. For that matter, with Phoenix still working its magic at the Martian pole, imagine subsurface aquifers on that planet whose energy resources may be just enough to keep microbes like these alive. And ponder the implication for life’s survival anywhere, for the sub-ocean floor may be the most bulletproof place on a planet, even when an incoming asteroid is substantial.
It seems remarkable to think that a large percentage of life on Earth — perhaps one-third of the planet’s biomass — may exist in forms that have yet to be subjected to laboratory analysis, but at least in this unusually active area off Peru, where organic materials are continually being deposited, microbes adapted to a far different kind of life than we are familiar with are flourishing. Reader Hans Bausewein, who sent links to this story, noted the tenacity of life that these results suggest. Get the process rolling and it seems to spread into every possible niche, at least on Earth, and the betting here is that the story is similar on other worlds.
The paper is Biddle et al., “Metagenomic signatures of the Peru Margin subseafloor biosphere show a genetically distinct environment,” Proceedings of the National Academy of Sciences, Vol. 105 No. 30 pp. 10583-10588 (July 29, 2008). Abstract online. Summary in this Penn State news release.
Hi Paul;
This is a very interesting article.
Micro-organisms that take hundreds to thousands of years to divide would practically be in suspended animation. Such slow growth reminds me of the rate of growth of certain formations in a commercialized tourist attraction cave I saw about a couple of weeks ago. The geological features or stalagmites and stalactites in this cave typically take 100 years to grow one cubic inch. If it were not for the genetic components of these micro-organisms, we might be tempted to think that they are natural inanimate molecular self assembly constructions.
A good example of a large macroscopic organism that lives for up to several hundreds of years is the Bonsai Tree. The burning bush of the traditions of some of Earth’s major religions that Moses accordingly saw, supposedly is still alive. This particular species of bush is known to live for thousands of years. I am amazed by micro-organisms that take up to thousands of years to divide by which growth of a cave formation at 1 cubic inch per century pales in comparison.
Thanks;
Jim
Interesting how they are able to slow down their metabolism so much?
Maybe this method can be applied to humans also.
Also makes them good panspermia candidates. A few thousand years travelling before reaching another larger body is not a big deal.
Only the high pressure, that these species are used to, makes that less likely, but there are probably a lot more types. I wonder whether rocks in high mountains ever have been explored like this. Such an environment is much more similar to Mars.
What most touched me, as Paul very well noticed, was that it seems almost impossible to get life on a planet completely extinct once it got hold.
I’d bet that IF evidence of past life is found on Mars, it must still exist somewhere on (or better “in”) the planet. The surface is cold, but there must be plenty layers with acceptable temperatures much deeper.
Hans
HI Paul,guess such critters brings new meaning to 401K. The note reminded
me of Freeman Dysons very interesting 1978 article I am sure you have seen,some
of your readers may not have……
Best,
Mark
http://www.aleph.se/Trans/Global/Omega/dyson.txt
Paul,
Sorry, here is the link to a text format of his article.
Mark
Sorry to be a pendant but please … on a science blog … a bacteriUM not a bacteriA (plural).
Not to be pedantic, but archaeons comprise an entire kingdom, ranging from species and strains that divide with a timetable similar to run-of-the-mill bacteria to the more exotic species described here. Their tendency to thrive (albeit sometimes slowly!) in extreme environments (high salt, low temperatures) indeed makes them attractive candidates for astrobiology – in only one example, a species of halophile can survive enclosed in salt crystals, and in such a suspended state can tolerate space-level vacuum and gamma radiation levels. An extremely underrated kingdom, situated between prokaryotes and eukaryotes, living in environments nearly beyond imagination.
Gregory Hallam writes:
Ouch, what a dumb gaffe. I’ve corrected it in the post above.
I have a groundhog problem. They are very cute pests because of the structure of my property, but pests nonetheless. For this reason I’ve done a lot of reading on their habits, mostly to figure out how to (humanely) manage them but also because I’ve found they’re quite interesting critters.
The reason I mention this is that lots of researchers study groundhogs (woodchuck, marmot) because they are awesome hibernators. NASA and a variety of universities are studying them to understand how they do it, the genetic basis, and how it can be applied to humans for medical purposes and for deep space voyages. The idea is that it is genetically based and an inherent ability in all mammals, if they can figure out how it’s done.
Here are a couple on non-technical articles. I haven’t dug up the scientific papers because I likely wouldn’t understand them if I did.
http://www.dallasnews.com/sharedcontent/dws/news/healthscience/stories/DN-hibernation_29nat.ART.State.Edition1.3eb4e3f.html
http://www.news.cornell.edu/Chronicle/97/1.30.97/groundhog_research.html
This is really awesome. Lots of implications for what we think of as “alive.” My question is this: don’t we plan to search for life on Mars (etc.) by first looking for traces of metabolic reactions? As the author implied, if life on other planets metabolizes extremely slowly, will we even be able to detect it by means currently available? Especially if the biochemistry is very different from what we expect. Maybe this just shows us that we need to take along more sensitive equipment than we thought.
At last, life that lives as slowly as I think.
One problem about slowing our metabolism to that “slow rate”, It would take a year to blink an eye. So what ‘s the point of having that slow of a metabolism if you move at the same rate as a stalagmite grows.