No Moon, no life on Earth, suggests theory

NewScientist.com ^ | 18 March, 2004

[Leroy S. Mort]

Without the Moon, there would have been no life on Earth.

Four billion years ago, when life began, the Moon orbited much closer to us than it does now, causing massive tides to ebb and flow every few hours. These tides caused dramatic fluctuations in salinity around coastlines which could have driven the evolution of early DNA-like biomolecules.

This hypothesis, which is the work of Richard Lathe, a molecular biologist at Pieta Research in Edinburgh, UK, also suggests that life could not have begun on Mars.

According to one theory for the origin of life, self-replicating molecules such as DNA or RNA emerged when small precursor molecules in the primordial "soup" polymerised into long strands. These strands served as templates for more precursor molecules to attach along the templates, creating double-stranded polymers similar to DNA.

But the whole theory fails without some way of breaking apart the double strands to keep the process going, says Lathe. It would take some external force to dissociate the two strands, he says.

Doubling up

As an analogy, he points to PCR, the technique used to amplify DNA in the lab. DNA is cycled between two temperatures in the presence of appropriate enzymes.

At the lower temperature of about 50 ýC, single DNA strands act as templates for synthesising complementary strands. At the higher temperature of about 100 ýC, the double strands break apart, doubling the number of molecules. Lower the temperature, and the synthesis starts again. Using this process, a single DNA molecule can be converted into a trillion identical copies in just 40 cycles.

Lathe believes that thanks to the Moon, something similar happened during Earth's early years. Most researchers agree that the Moon formed five billion years ago from debris blasted off Earth in a giant impact.

A billion years later when life is thought to have arisen, the Moon was still much closer to us than it is now. That, plus the Earth's much more rapid rotation, led to tidal cycles every two to six hours, with tides extending several hundred kilometres inland, says Lathe. Coastal areas therefore saw dramatic cyclical changes in salinity, and Lathe believes this led to repeated association and dissociation of double-stranded molecules similar to DNA.

When the massive tides rolled in, the salt concentration was very low. Double-stranded DNA breaks apart under such conditions because electrically charged phosphate groups on each strand repel each other.

But when the tides went out, precursor molecules and precipitated salt would have been present in high concentrations. This would have encouraged double-stranded molecules to form, since high salt concentrations neutralise DNA's phosphate charges, allowing strands to stick together.

Unrelenting cycles

These unrelenting saline cycles would have amplified molecules such as DNA in a process similar to PCR, says Lathe. "The tidal force is absolutely important, because it provides the energy for association and dissociation [of polymers]."

Many researchers do not believe DNA and RNA were the first replicating molecules. Graham Cairns-Smith of the University of Glasgow, UK, thinks much simpler "genetic" material formed first, from the crystallisation of clay minerals.

But he says Lathe's idea deserves attention. "Whatever the replicating entities were that started the evolutionary process, it would be significant that they lived in an environment in which the conditions were changing."

If the theory is right, life could not have evolved on Mars, says Lathe. Phobos, the larger of Mars's two Moons, is so small that the tidal forces it generates are just one per cent of those generated by our Moon. "Even if there was water on Mars, life could not have evolved there because these polymers could not have replicated," he says.

[K1avg]

Wow, it's bad enough that they try to force this spontaneous generation garbage down our throats, but now they argue that the moon is responsible for life?

Sheesh...

[LiteKeeper]

The DNA carries information that is used like a blueprint to build proteins out of amino acids. Where did that "information" come from? Information is never self-generated, nor can "matter" generate information. So all that DNA needs a source for it's information. Any ideas where it comes from?

[BenLurkin]

When the moon hits your eye like a big-a pizza pie
That's amore
When the world seems to shine like you've had too much wine
That's amore

Bells'll ring ting-a-ling-a-ling, ting-a-ling-a-ling
And you'll sing "Vita bella"
Hearts'll play tippi-tippi-tay, tippi-tippi-tay
Like a gay tarantella

When the stars make you drool joost-a like pasta fazool
That's amore
When you dance down the street with a cloud at your feet, you're in love
When you walk in a dream but you know you're not dreamin', signore
'scusa me, but you see, back in old Napoli, that's amore

(When the moon hits your eye like a big-a pizza pie, that's amore)
That's amore
(When the world seems to shine like you've had too much wine, that's amore)
That's amore

Bells will ring

ting-a-ling-a-ling

ting-a-ling-a-ling

And you'll sing "Vita bella"

Vita bell-vita bella

Hearts will play

tippi-tippi-tay, tippi-tippi-tay

Like a gay tarantella

Lucky fella

When the stars make you drool just like pasta fazool
That's amore (that's amore)
When you dance down the street with a cloud at your feet, you're in love
When you walk in a dream but you know you're not dreaming, signore
'scusa me, but you see, back in old Napoli, that's amore

Amore
That's amore

[Fiddlstix]

Ping

[Diogenesis]

polyAAAAA reproduces itself.
All life has DNA which begins with polyAAAAA.
The DNA which was best covered and protected, then did the best.

[Ken522]

Without the Moon, there would have been no life on Earth.

Wait - this might be the secret justification for worshipping the moon after all!

[orionblamblam]

> spontaneous generation garbage...

Wait. Where were Creationists mentioned int he article? They're the only ones yapping about "spontaneous generation garbage" as part of their biogenesis "theory..."

[BikerNYC]

Any ideas where it comes from?

I don't know, but if it comes from somewhere, I am really curious as to how that "somewhere" got it.

[djf]

Correct. I think early environments needed to be "contained" in some sense. The best way to desribe it is that early life probably resembled, more than anything else, something that had the consistency of egg whites. Having a thicker type medium prevents the whole mess from being diluted and washed out into the open oceans.

I have written an essay on the subject that a few have read, I remember being stunned by the findings of Thermus Aquaticus and TAQ polymerase.

The development of the cell wall, well, that's another whole problem entirely...

[LiteKeeper]

Perhaps the Eternal God had "it" all along, and when He created life, He made that part of the package. Methodological naturalism [read, "evolution"] can not come up with any better explanation. Abiogenesis is impossible...and that has been demonstrated over and over again.

[BikerNYC]

But I thought you said it had to come from somewhere. Your violating your own premise by saying that at some point it did not have to come from somewhere...that it was always there.

I don't see how your theory solves any problems.

[fella]

Looks more and more like the Earth is the only place where the Lord has placed life. And He told us to go forth and multiply .... Out there.

[djf]

And God said, "Let the waters bring forth abundantly the moving creature that hath life..." Gen 1:20

[staytrue]

The cell wall is mostly a glob of fat or oil that forms a bubble in water. A lot of fats will do this spontaneously.

[GeronL]

My GUANO detector is hitting the higher frequencies with this story. Pure BS

[pepsionice]

One curious thing...which I don't think anyone caught...is that the moon used to be a lot closer billions of years ago...so does this mean that it is slowly creeping away from the earth...even today?

[socal_parrot]

Actually, they were talking about Christopher Cross' musical careear. After all, without the moon, what else would you be stuck between with New York City.

Best that you can do is fall in love...

[orionblamblam]

> does this mean that it is slowly creeping away

Yes, it is, at a rate of centimeters per year, IIRC. This has been repeatedly measured using lasers and the reflectors left by the Apollo astronauts.

What is happening is that tidal forces are in play. The total angular momentum of the Earth-Moon system is remaining essentially constant, but the system, via tidal drag, is exchanging the Earth's rotation for the moons revolution. Basically, the day AND month are getting longer. As memory serves, in some billions of years both will be approximately twice what they are now. And then the sun will go FOOM, and the issue becomes moot.

[farmer18th]

These tides caused dramatic fluctuations in salinity around coastlines which could have driven the evolution of early DNA-like biomolecules.

could

what speculative drivel. Does someone get paid to write this nonsense?

[Kerberos]

"My GUANO detector is hitting the higher frequencies with this story. Pure BS"

Yeah to think that some people actually beleive in evolution. Where do they come up with these people.

[Lawgvr1955]

The current rate of recession is approximately 4 cm per year. Plus the sun is slowly expanding and the earth's rotation is slowing, causing the day to be longer. Remember the old adage, nothing last forever.

[GeronL]

I didn't say anything about evolution. I am referring to giving the moon credit for the start of life. THATS plain silly.

[Ken H]

Actually, they were talking about Christopher Cross' musical careear. After all, without the moon, what else would you be stuck between with New York City.

That is certainly a possibility.

If I'm not mistaken, it is believed that there used to be a river on the moon. It was wider than a mile.

[Auntie Dem]

"...nothing last forever.

Forever lasts forever. ;^)

[Auntie Dem]

now they argue that the moon is responsible for life?

Maybe it was the Moon God

[socal_parrot]

Below is the Mayan Moon God Tanah,

It is available for $150 from www.awrem.com.

[ASA Vet]

Even if there was water on Mars, life could not have evolved there

And when they find just one small fossil found there?

[Virginia-American]

Information is never self-generated, nor can "matter" generate information.

Why not?

How did the information about how to metabolize nylon arise? Analysis shows that the nylon-eating bugs are a single base pair mutation different from the wild (carbohydrate-eating) bugs.

Mutation occurs in nylon-free environment (eg before the '30s) : bacterium dies
Mutation occurs in nylon-rich environment : bacterium flourishes, reproduces. It's 'discovered' a new, totally-unoccupied, niche.

So where did the information come from? It seems to me it came from the environment to the genome. Self-geenerated by matter.

[Consort]

[LiteKeeper]

PLease check this out

Bacteria that will eat your stockings?

That depends on what your definition of ‘information’ is

[Kerberos]

"I didn't say anything about evolution. I am referring to giving the moon credit for the start of life. THATS plain silly."

Not any sillier than creationism.

[Lawgvr1955]

Forever lasts forever.

Whoa!! Dude!! You're freakin' me out, man.

[VadeRetro]

Another abiogenesis theory (and the Luddites are in full screech mode).

[PatrickHenry]

PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]

[Mamzelle]

re: A billion years later when life is thought to have arisen)))

You can't ever write these sorts of articles without heavy use of the passive voice combined with vague references to an ungraspable passage of time--

But you particularly need the passive voice to imply that such assumptions are sorta really kinda actually (Hans Vavink ) beyond question except for knuckle-dragging fundamentalists...

And somebody please write this guy a nice research grant...

Hey, Pat, did we ever get those new fruit flies?

[Larry Lucido]

We Like The Moon.

[PatrickHenry]

The role of the moon has been discussed before: Rare Earth.

[Alamo-Girl]

Thanks for the ping!

[RadioAstronomer]

My GUANO detector is hitting the higher frequencies with this story. Pure BS

Well kinda. If you look at the Earth's tilt in reference to the ecliptic plane, the Moon seems to have played a large part in keeping it stable. This of course causes the seasons we have. Without the Moon, life may be far different that what we have today.

[RightWhale]

It might be that the constantly changing conditions caused by tides would force lifeforms to higher behavior. Earth's rotation would provide this even without the moon, but the cycle would be simple. It's one thing to grow in a Petri dish, but another to be out in cyclical conditions. There is the daily sun cycle and the seasonal cycle, but adding the moon as another harmonic would complicate the enviroment. The complex cycles would force complex adaptation.

[balrog666]

Without the Moon, life may be far different that what we have today.

I want a Moon!

[jennyp]

could

what speculative drivel. Does someone get paid to write this nonsense?

Yeah, who do these people think they are coming up with hypotheses - scientists?

And what makes these so-called scientists think they can get away with making anything less than categorical assertions of god-like certainty? Anything less than WWF-like bravado is the same as total capitulation to all alternate theories. Science has NEVER made progress by making tentative, qualified statements.

[Dimensio]

Abiogenesis is impossible...and that has been demonstrated over and over again.

I must have missed this. Could you provide a reference to where it was demonstrated that abiogenesis is completely impossible?

[farmer18th]

Yeah, who do these people think they are coming up with hypotheses - scientists?

Doubt it. Scientists have at least some remote chance of observing phenomena.

[Junior]

It's a common human failing to be suspicious of those more -in-the-know than you are. Hence, folks who have absolutely no clue as to what they are talking about will make broad-brush condemnations of actual research in the field, because "them there pointed headed int-uh-lectules can't possibly know what they is talkin' 'bout."

[edwin hubble]

"If you look at the Earth's tilt in reference to the ecliptic plane, the Moon seems to have played a large part in keeping it stable. "

Hello, RadioAstronomer. I was aware of the mechanics of lunar orbit and the effect of the moon on the stability of Earth's axis over time.

Are you aware of any evidence of a long-term process of axis tilt (tumbling) by Mars or Venus?

---
Also, I can certainly see that stronger tides in earlier eras might have affected shoreline environments in coastal waters (early life in the inter-tidal zones).

The implications are obvious for Weak Anthropic Principle: human-like life would be even more rare.

and it would mean a much lower value of the Drake Equation variables Ne and Fl: a lower probability of extraterrestrial life.

[Ne: For each star that does have a planetary system, how many planets are capable of sustaining life?

[Fl: On what percentage of the planets that are capable of sustaining life does life actually evolve? ]

--
Also...
Tectonic Plate activity, (complex in origin and apparently unique in the solar system) likewise has been cited by others as necessary-for-longterm-life on Earth.

[longshadow]

rare placemarker

[RadioAstronomer]

Are you aware of any evidence of a long-term process of axis tilt (tumbling) by Mars or Venus?

From here:

http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/611spati.asp

"While Earth’s axial tilt has only varied between 22 to 24.5 degrees in the past 10 million years, Mars has experienced a more extreme wobble, ranging from 14 to 48 degrees."

Another interesting read:

http://www.rps.psu.edu/jan97/planets.html

"The obliquity of a planet is the angle of its spin axis -- that imaginary rod that skewers a planet through the poles -- in relation to the plane of its orbit. In Earth's case, this angle is a modest -- and reasonably steady -- 23.5 degrees, enough of a tilt to account for our seasons. Because of Earth's obliquity, in the northern hemisphere the winter sun stays low in the sky, casting its rays obliquely across the landscape. In summer it climbs to more nearly overhead, an angle much better for warming."

---snip---

"Mars, Laskar showed, still does, its obliquity varying chaotically between 0 and 60 [Note: I did notice there was a difference in the numbers] degrees. The only thing that saved Earth from a fate worse than Mars', he says, was hooking up with the moon.

A little orbital mechanics may be in order here. Earth is a body in complex motion. It rotates, of course, once every 24 hours. At the same time, on a different time scale, it revolves around the sun. But there are other, subtler, motions which must also be accounted for. Earth's imperfection as a sphere, for one thing, adds a motion called precession, akin to the wobbling of a spinning top. Earth wobbles, as noted above, only slightly and in very slow motion, its obliquity oscillating from 22 to 24 degrees every 40,000 years.

Meanwhile, however, the gravitational pull of the other planets in the solar system, especially the giants Jupiter and Saturn, causes a different kind of precession: a wobble in the plane of Earth's orbit. Imagine the orbital plane as a solid object, a spinning frisbee or a dinner plate, with the sun a dollop of mashed potatoes in its center, and Earth a wad of chewing gum stuck to its outer rim. The insistent tug of these outer, larger planets against the sun's stronger pull causes the plate to wobble as it spins.

The real action, in terms of shifting obliquity, comes when these two types of wobble -- the planetary and the planar -- stumble onto the same frequency. Then you get what's known as a spin-orbit resonance: in synch, the two motions combine their energy, creating a much larger force. It's not unlike the kind of timing it takes to keep a hula-hoop spinning around your hips, or to successfully push a child's swing. For a planet, however, resonance means chaos, as two small competing wobbles become one huge concerted one.

What saves Earth from falling into a spin-orbit resonance, Laskar says, is the moon. Because of its size and proximity, the moon exerts a strong gravitational pull of its own on our home planet -- a pull which turns out to be a stabilizing influence. The lunar effect acts to accelerate Earth's global precession, maintaining it at a steady frequency well higher than the torpid wobbling of the orbital plane. Take the moon away, Laskar says, and keep things otherwise the same -- give Earth the same mass, orbital position, rotation rate, etc. -- and Earth's obliquity would fluctuate between 0 and 85 degrees."

and it would mean a much lower value of the Drake Equation variables Ne and Fl: a lower probability of extraterrestrial life.

That I am not sure of. Life may be just as likely, but adapted to those environments. I just dont know. Life sure seems to be able to live in the extremes on this planet.