Origin of life on Earth: the 'natural' asymmetry of biological molecules may have come from space

AlphaGalileo ^ | Friday, January 7, 2011 | CNRS

[SunkenCiv]

Certain molecules do exist in two forms which are symmetrical mirror images of each other: they are known as chiral molecules. On Earth, the chiral molecules of life, especially amino acids and sugars, exist in only one form, either left-handed or right-handed. Why is it that life has initially chosen one form over the other? A consortium bringing together several French teams led by Louis d'Hendecourt, CNRS senior researcher at the Institut d'astrophysique spatiale (Université Paris-Sud 11 / CNRS), has for the first time obtained an excess of left-handed molecules (and then an excess of right-handedones) under conditions that reproduce those found in interstellar space. This result therefore supports the hypothesis that the asymmetry of biological molecules on Earth has a cosmic origin. The researchers also suggest that the solar nebula formed in a region of massive stars...

Chiral molecules are molecules that can exist in two forms (enantiomers) which are symmetrical mirror images of each other, one left-handed and the other right-handed. For instance, our hands are chiral since they come in two forms, the left hand and the right hand, that are symmetrical with their mirror image but not super imposable on it. Biological molecules are mostly chiral, with some forms being favored over others. For instance, the amino acids that make up proteins only exist in one of their two enantiomeric forms, the left-handed (L) form. On the other hand, the sugars present in the DNA of living organisms are solely right-handed (D). This property that organic molecules have of existing in living organisms in only one of their two structural forms is called homochirality.

[MsLady]

I'm with you!!!

Origin of life on Earth: the 'natural' asymmetry of biological molecules may have come from space

HELLLOOOO, planet earth is in space. Or maybe they are talking about the space between their ears?

[ApplegateRanch]

Asimov did at least one science-fact column, if not a series of columns, about this subject in the Magazine of Fantasy & Science Fiction, waaaaay back.

Levo-rotary & dextro-rotary organic molecules: the hows, whys, whats, and implications to life on earth explained, as only he could explain them for the layman.

[LoneRangerMassachusetts]

The naturalists are insistent upon keeeping up the facade that they are ever closer to uncovering the mysteries of life. Experiments aren’t going well on this planet, but you just know that conditions in some other world were just right. And ofcourse intelligent beings transported life to earth! Aha! Bob

Seems to me that science based on medical biology has mad great progress in understanding natural processes. In the same time I have not seen Religion advance one step. All the praying in the world does the Copts zilch.

[dr_lew]

Right away I thought of the verse from Ecclesiastes, "Whether a tree falleth to the north or the south, there it shall lie". That is, one or the other enantiomer is bound to prevail.

But then, the entire verse, Ecclesiastes 11:3 is,

3 If the clouds be full of rain, they empty themselves upon the earth: and if the tree fall toward the south, or toward the north, in the place where the tree falleth, there it shall be.

So whoa: "empty themselves upon the earth" Is that an adumbration of panspermia?

[AndyJackson]

Any sort of a lire from space theory is basically just kicking the can down the road a block or two

Not at all. As the article indicates, one can assume that both chiralities were produced equally, however, in passage to the earth they pass through an infrared radiation field which, because of the interplanetary magentic field, and the plasma therein, is circularly polarized, and will interact with one chirality much more strongly than the other, thus producing an excess abundance of the second over the first. If no other part of the theory is credible, this part is solid, rather basic, physics.

[BroJoeK]

alstewartfan: "To me, the preponderance of ever sillier theories illustrates the deperation and frustration experienced by Darwinists trying to make sense of the origins of life. Bob"

Why would you imagine that God might make His best work easy for humans to understand?
When did any important accomplishment come easy?

[BroJoeK]

muawiyah: "See how desperate the "little earth" crowd is to hang onto the idea that life originated here and it originated one time and that's all there is to it."

The idea that some chemical "building blocks" of life may have arrived aboard meteors or comets has been around for a very long time now.
So, no scientist argues that it could not happen, only that the evidence for it is, well, not yet conclusive.

For example, of all these "building blocks" in outer space, which ones could not have formed, given its earliest conditions, on Earth itself?

muawiyah: "But, once you find out that one of the processes has to have an outer space origin..."

"has to" is a pretty strong term.
The article itself only claims:

"This result therefore supports the hypothesis that the asymmetry of biological molecules on Earth has a cosmic origin."

"Supporting a hypothesis" is not exactly the same thing as proving a theory. ;-)

[muawiyah]

What happens here is that life on Earth has bias in one direction for certain classes of chemicals and a bias in a different direction for a different class of chemicals ~ both classes necessary for life.

The hypothesis here is that these two biases are easily created in outerspace but cannot otherwise be 'splained in an Earth environment.

[tacticalogic]

IIRC, there is no known physical, chemical, or electrical process that explains much of the behavior of the molecules in a living cell.

These things are either self-aware and acting on purpose, which is preposterous, or something is directing them.

The implicit premise between your observation and your conclusion is that all physical, chemical, and electrical processes are known.

[alstewartfan]

Whether one believes that there is intelligent design or randomness, all scientists assume when they present a hypothesis that the physics of the universe is discernable to us. Virtually ALL of the great scientists of the past were Christians who assumed that God allowed humans to understand the world.
My point is that our existence has been clearly designed. Most mutations are desructive to life; yet we know that many millions of POSITIVE mutaions were necessary for life to exist as we know it. It’s time that the scientific commnity started to appreciate the forest behind the trees. Bob

[tacticalogic]

Where did the molecules originate from on the planets/asteroids/space dust that that brought them to earth?

This answers nothing.

Then finding out where something came from before it was here never answers anything, because it was always somehwhere else before that. I guess we should just stop asking. Curiousity, research and discover are is a waste of time.

[BroJoeK]

muawiyah: "The hypothesis here is that these two biases are easily created in outerspace but cannot otherwise be 'splained in an Earth environment."

I have no problem with the hypothesis, or it's extraterrestrial implications -- just not certain if it's confirmed, or "proved", and don't see how, outside of scientific curiosity, it makes all that much difference either way.
;-)

[AdmSmith]

d-amino acids are produced by many bacteria.

http://www.hhmi.org/news/waldor20090918.html

[WorkingClassFilth]

Depends on whether you like the answers you are looking at. If life originating on earth seems too improbable so that the easiest solution becomes extraterrestrial, seems to me that you've only sidestepped the question.

An enormous number of ‘scientific’ discoveries are serendipitous - that is, they fall into researcher's ’s laps despite their looking for them. Additionally, many scientists of the past and present have had no problems with the idea of a Creator God at work in our world. Of course, ‘modern’ minds don't accept such rubbish and need to look for answers someplace else - like Star Trek reruns.

[tacticalogic]

Depends on whether you like the answers you are looking at.

If there's only certain answers you will accept, then you aren't doing research, you're just trying to rationalize your preconceptions.

I don't see anything in this that would prove or disprove the existence of a Creator God. Why do you think it would?

[tacticalogic]

Depends on whether you like the answers you are looking at.

If there's only certain answers you will accept, then you aren't doing research, you're just trying to rationalize your preconceptions.

I don't see anything in this that would prove or disprove the existence of a Creator God. Why do you think it would?

[WorkingClassFilth]

“Certain answers” are taught everyday in every science class across the world - evolution is taught as fact although, honestly, it is taken (just like creation) on a faith supposition. Since fields like molecular biology have opened previously closed realms, it has become increasingly difficult for evolutionists to account for the origins of life with what we see and it becomes terribly convenient to expand the laboratory to the ultimate unknowable - the universe. Of course, this tends to derail the embarrassing challenges many are making about the mind boggling complexity of single cells alone. Seems to me that preconceptions are pretty flexible ideas and pretty much depend on which side of the fence you find yourself on. Speaking as a former researcher, if you don’t think they guide research, you are overlooking human nature and only feeding some weird and pridefull notions about the sanctity of science.

FWIW, historic, literal and internally consistent Bibilical concepts of creation and evolutionary doctrine are pretty much mutually exclusive. For more detailed information, there is plenty out there from the perspective of boatloads of theologians and scientists alike - not to mention Christ himself.

[tacticalogic]

I understand that “weird and prideful” notions are part of human nature. I commit the indescretion of believing that people are as also succeptible to prideful behaviour with regard to their religious beliefs.

[Westbrook]

> The implicit premise between your observation and your
> conclusion is that all physical, chemical, and electrical
> processes are known.

Not at all.

I said there are no KNOWN processes, which has the very opposite implication as the one you posit.

However, I do submit that no natural force will ever be discovered that would cause these molecules to behave this way.

Consider the RNA molecule that unzips a part of the DNA strand, knowing exactly where to go, reads part of the code to construct a certain protein, copies it, rezips the DNA strand, carries the information to the area where the protein is being assembled, makes its contribution to the project, and repeats the entire process until the protein is complete.

What possible natural force can even invent, let alone direct this process?

I submit it is a Supernatural Force.

Where there is code, there must be an author.

Where there is design, there must be a designer.

[tacticalogic]

Okay. You have a theory, and some evidence to support it.

If it's OK for you to state that theory as fact, without having to explicity explain that it is just an uproven theory, then we'll make that the accepted standard.