Alive and Well In a Block of Ice

New studies of hibernating bacteria show how DNA can repair and maintain itself over hundreds of thousands of years. That has big meaning for life in space.

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An Apollo 12 astronaut places an Apollo Lunar Surface Experiments Package on the Moon.

The Apollo 12 astronauts were not the only living organisms on the surface of the moon when they landed there in November of 1969. That’s not conspiracy theory looniness. It’s what serious scientists concluded when the crew came back and what a lot of them still believe. The astronauts’ lunar module touched down within walking distance of the unmanned Surveyor 3 probe, which had soft-landed on the airless, windless surface of the moon three years earlier. Part of the reason for choosing that spot was so that the astronauts could retrieve Surveyor’s camera and a few other small parts of the ship and bring them home, where scientists could examine how well terrestrial hardware fares under space conditions.

The machinery aboard Surveyor, they discovered, held up just fine. Much more remarkably, so did the biology. Deep within some of the batting inside the camera was a small colony of streptococcus bacteria which, when cultured, bestirred themselves and resumed growing and dividing. The conclusion: the camera had been contaminated by technicians before it left Earth, and the bacteria had put themselves into a state of suspended animation, waiting for the unlikely day they’d find themselves in a more hospitable environment.

In the years since, some of the luster has come off of this story. A 2011 review of the findings concluded that the camera was contaminated not before it left Earth, but in an imperfectly sterilized clean-room after it returned. Other reviewers dispute that, however, pointing out that the bacteria were very slow to revive upon culturing and that only a small handful of them succeeded, consistent with organisms that had indeed been dormant for a long period of time.

(MORE: Did a Distant Solar System Send Life to Earth?)

Whatever the true provenance of the Apollo 12 bugs, they were the first hint of what is now the robust study of life in extreme environments—in boiling sea vents, dry desert stones and, significantly, in ancient ice.  Viable micro-organisms have been found in Siberian permafrost after 30,000 years of suspended animation. In one case, investigators recovered and revived bacteria from the depths of the Guliya ice cap in western China, where the bugs had been slumbering for an astounding 750,000 years.

“One of the fundamental problems that has been tossed around is how this is possible,” says Brent Christner, professor of biological sciences at Louisiana State University.”These bugs must have some sort of extraordinary DNA remair mechanism, but no one knows what it is.”

Now however, thanks to an imaginative study conducted by Christner and his colleagues, and published in the journal Applied and Environmental Microbiology, we’re a little closer to that knowledge than we were. That has big implications for our basic understanding of both terrestrial biology and, much more tantalizingly, the extraterrestrial kind.

(MORE: Alien Life Discovered in a Meteorite! Or Maybe Not)

The biggest problem facing organisms consigned to the deep freeze is not so much the low temperature as the high radiation. All living things on Earth are subjected to background levels of natural radiation, which don’t amount to much in any given moment, but accumulate over the years and millennia. Space, without Earth’s protective atmosphere, is a far deadlier environment, with radiation levels climbing to intensities that would quickly kill unshielded humans outright. The worst kind of damage the radiation does is what’s known as double-stranded DNA breaks, in which the molecules fracture into separate pieces, which themselves break up more and more over time. We survive this thanks to a well-understood DNA repair system in our cells. For frozen bacteria to survive an exponentially longer period, a related mechanism must be at work.

To try to determine what that mechanism is, Christen and his colleagues began with a healthy population of Psychrobacter arcticus bacteria which, as their surname suggests, were first discovered in permafrost, in this case in Siberia. The investigators didn’t have the freedom to freeze the bacteria and then study them for 750,000 years, but they were able to accelerate the process a bit by exposing them to a dose of ionizing radiation equivalent to what they’d absorb on Earth over the course of 225,000 years. Then they froze the Psychrobacter at a temperature of 5° F (-15° C), and checked on them periodically over the course of two years, intermittently sampling small bits of their DNA.

No surprise, the DNA strands did not fare well, some of them fragmenting into what the investigators called a “slurry” of smaller bits. But some of the DNA looked just fine, and that meant something was indeed intervening to knit the strands back together. “This isn’t a random process,” Christner said in a release accompanying the paper. “This tells us the cells are repairing their DNA. [Emphasis in the original.] This is important because we don’t typically think of these as being conditions under which complex biological processes are going on.”

(MORE: DNA in Space? Biological Building Blocks Found in a Meteorite)

Laboratory proof that such repair work does happen in those environments is no small thing. It doesn’t bring Christen and his colleagues much closer to pinpointing the mechanism yet, but they have some ideas. It’s possible, for example, that the  structure of ice provides bacteria small, liquid redoubts in which conditions are marginally milder. “When you freeze water you create an ice crystal latticework,” Christen says. “Impurities like salts and the bacteria themselves become segregated there.” And since those tiny pockets can remain liquid, the DNA might repair itself just as it does in organisms living in friendlier places. But, Christen admits, that’s just one theory. “If we did this experiment and we had no evidence that DNA was being repaired, we’d be studying an alternate hypothesis,” he says. “Now we know it can happen and this gives us new avenues to pursue.”

One thing Christen is sure of is what his work suggests about the possibility of life in deep space—including in our own solar system. “It just keeps looking better for conditions of habitability on Mars,” he said in the release. “If these DNA repair mechanisms operate in Earth’s cryosphere, extraterrestrial microbes might be using this survival mechanism to persist on other icy worlds.” Life may or may not be everywhere, but if the new findings show anything, it’s that when the need arises, it can be tough as nails.

(MORE: Aliens Among Us)

2 comments
eagle11772
eagle11772

"Life" on a grand scale, seems to be indestructible, and is a natural consequence of the machine we call "The Universe".  I believe hat the entire purpose of the machine, from galaxy clusters down to subatomic particles, is to produce LIFE, in great varieties, great quantities, and great complexity.  We, and all life forms, are after all, stardust.

BabuG.Ranganathan
BabuG.Ranganathan

THE CELL IS IRREDUCIBLY COMPLEX

The courts rejected teaching of irreducible complexity not because it wasn't scientifically supported, but because the courts said it would violate separation of church and state to allow intelligent design to be taught. However, there is no real violation of church and state separation because no one is being forced to believe in God.

Irreducible complexity has been supported over and over again scientifically. A partially-evolved organism is impossible. All organisms and all species, their biology, their bio-chemistry, their tissues, organs, and biological systems have to be complete and fully functioning from the start to be viable or fit for survival.

The cell, indeed, is irreducibly complex. For example, without DNA there can be no RNA, and without RNA there can be no DNA. And without either DNA or RNA there can be no proteins, and without proteins there can be no DNA or RNA. They're all mutually dependent upon each other for existence! It could not have gradually evolved! Evolutionists generally believe that it took one billion years for the first cell to have evolved. That belief, taught as gospel in science textbooks, cannot be supported by actual science.

The millions of molecules (various kinds of nucleic acids and amino acids) in a cell must be in the right sequence, just like the letters in a sentence. If they're not in the right sequence the molecules won't work. There's no law in chemistry or physics that the molecules have to be in a sequence. They can come together in any order, but the fact that we find them in a sequence points to an intelligent cause.

Natural laws may explain how the cell works and reproduces, but undirected natural laws cannot explain the cell's origin.

Once you have a complete, living, and fully functioning cell, then the genetic program and biological parts exist to direct the formation of more cells. But, this doesn't explain how the cell could have come into existence when no directing mechanism existed in nature.

Many think that natural selection in nature is proof that we had evolved, but natural selection itself does not produce biological variations. It can only “select” from biological variations that are possible, and it can only operate once there is life and reproduction, not before. In other words, natural selection could not have been involved in life’s origin.

 If the cell had evolved it would have had to be all at once. A partially evolved cell (an oxymoron) cannot wait millions of years to become complete because it would be highly unstable and quickly disintegrate in the open environment, especially without the protection of a complete and fully functioning cell membrane. Even a once living cell quickly disintegrates once it’s dead.

The great British scientist Sir Frederick Hoyle has said that the probability of the sequence of molecules in the simplest cell coming into existence by chance is equivalent to a tornado going through a junk yard of airplane parts and assembling a 747 Jumbo Jet!

What about “Junk DNA”? The latest science shows that “Junk DNA” isn’t junk after all! It’s we who were ignorant of how useful these segments of DNA really are. Recent scientific research published in scientific journals such as Nature has revealed that the “non-coding” segments of DNA are vital in regulating gene expression (i.e. when, where, and how genes are expressed).

For more information, read my popular Internet article, SCIENCE AND THE ORIGIN OF LIFE

Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION . I discuss: Punctuated Equilibria, "Junk DNA," genetics, mutations, natural selection, fossils, dinosaur “feathers,” the genetic and biological similarities between various species, etc., etc.

Babu G. Ranganathan*
B.A. Bible/Biology
 
Author of popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS
 
*I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I've been privileged to be recognized in the 24th edition of Marquis "Who's Who in The East" for my writings on religion and science.