How did life begin?

Creatio ex Nihilo
A MOST IMPORTANT UNANSWERED QUESTION

Here’s a question that science has asked and not yet definitively answered:

“How did life on earth begin some 3.6 billion years  or more ago?”

There are a variety of theories—one might better call them speculations—but until a model is produced that can be empirically verified, it will remain a scientific mystery.   I won’t explore this topic fully here—it would take a book—but links are given to articles that develop the various models.

 

PROBLEMS IN A THEORY OF HOW LIFE BEGAN
The problem in establishing a theory of how life began is that the constituents of life are large, complicated molecules:  DNA, RNA (nucleic acid chains), proteins (amino acid chains), membranes (phospholipid chains).    So one not only has to wonder how the constituent  molecules—nucleic acids, amino acids, phospholipids—were obtained from primitive chemicals in the early earth, but how these molecules were assembled into the complicated large, macromolecules that are the building blocks of cellular life.
There are various speculations—theories, if you will—about the origin of life on earth that are chemically based.    I’ll summarize some of them below very briefly.   For a more extended discussion, the Wikipedia article on abiogenesis is a good starting point.

 

CHEMICAL MODELS TO GET BUILDING BLOCK MOLECULES
In taking stock of these these theories, one should note that the atmosphere of the very early earth lacked oxygen (so organic molecules would not then react and decompose) and was probably rich in nitrogen containing molecules, HCN (cyanic acid) and NH3(ammonia),  as bricks for amino acids.
  • Primordial Soup:  the early oceans were warm and full of chemicals; these reacted after sufficient time to form the building blocks and then the long chains (improbable reactions, but remember there was a long time for the pot to cook);
  • Electrical Synthesis:  the building block molecules were formed by electrical discharge—lightning—acting on simple nitrogen containing molecules;
  • Clay Template: the building block molecules and long chain molecules were formed by surface reactions on clay, which set structures and catalyzed the reaction;
  • Undersea Hot Mineral Vents: hot undersea volcanic vents provided high temperatures to accelerate reactions, minerals to act as catalysts, and lots of inorganic and organic compounds as building blocks
  • Panspermia:  the building block molecules came from outer space, either planted deliberately by aliens, or by chance from meteors, comets or cosmic dust;  the question is, from where did these chemicals or aliens originate?
SPONTANEOUS SELF-ORGANIZATION
There are other models, which are based on spontaneous self-organization, derived either from a theory of autocatalytic sets (Stuart Kauffman) or from principles of irreversible thermodynamics (Jeremy EnglandIlya Prigogine ).
Example of spontaneous self-organization:
milk rings formed in coffee mug left in refrigerator
One primitive example of spontaneous self-organization is shown in the image above.  It is an example of smoke rings or, more technically, “vortex rings”.

 

The origin-of-life theories referred to above are interesting, albeit speculative since they have not yet been subjected to detailed analysis and empirical proof.

Nevertheless, it is hard to disagree with the generalization of the Noble Prize winner, Ilya Prigogine:

“We know today that both the biosphere as a whole as well as its components, living or dead, exist in far-from-equilibrium conditions.  In this context, life, far from being outside the natural order, appears as the supreme expression of the self-organizing processes that occur.” —Ilya Prigogine, Order out of Chaos, p. 175

FINAL THOUGHTS: PURPOSE IS REQUIRED
It appears, as the opening quote suggests, that the origin of life is clouded in several mysteries:
  • First, how were the building blocks of life–amino acids, nucleic acids, phospholipid chains–formed?
  • Second, how did these building blocks assemble into the biological polymers–proteins, DNA, RNA, membranes?
  • Third, how did these assembled polymers come together to form primitive cells?
The likelihood of these events having occurred randomly seems very small, but there was indeed a very long time, over a billion years, over which they could occur.
I believe a more likely explanation is that a teleological principle–purpose–is at work, as proposed by the philosopher Thomas Nagel  in his book Mind and Cosmos.   Unlike Nagel (a confirmed atheist), I believe this purpose is achieved by God, using either little nudges at appropriate instances, or by some general mechanism He installs at the beginning, unknown to us now. and possibly forever.  Perhaps Scripture is a better guide than science here.

“I have made the earth, and created man upon it: I, even my hands, have stretched out the heavens, and all their host have I commanded.”  Isaiah 45:12 (KJV)

The evidence for Creation by God, both of the universe and of life, is not given here;  however arguments to this are given in other posts on this blog, for example, Are We Special–New Thoughts about the Anthropic Principle, and in my web-book,”Truth Cannot Contradict Truth”.

 

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10 thoughts on “How did life begin?”

    1. Thanks for the comment Captcrisis, even if it be somewhat snarky. I think what you probably meant (or should have meant) to say is “waiting for an actual biochemist to weigh in.” Because it’s more a matter of chemistry, biochemistry and biophysics than biology to understand how building block molecules were formed from available chemicals and how biopolymers–proteins, nucleic acid chains, phospholipid chains and thence membranes and cells were formed from these building block molecules. I hesitate to blow my own horn, but I have published (collaboratively) in biochemical and biophysical journals.

      But it’s more than knowing the ins and outs of the Krebs cycle. There’s a basic scientific criterion to be applied to any explanation of how life began. And that’s empirical verification by repeated observations or experiments. So even a biologist can evaluate a geological theory–e.g. plate tectonics–by applying this criterion. And if you do the literature searches you’ll see that hasn’t been done.

    2. As a BioChemist myself, I can’t imagine how anyone would fail to see the obvious “intelligent design” of the Genetic Code (to put it mildly). With the approach of Thanksgiving, you may all wonder about the Genetic Code of Tryptophan. Tryptophan is the amino acid that is said to be abundant in turkey, and is said to be the cause of sleepiness during NFL football games…but that is another story.

      The Genetic Code of Trytophan is simply TGG. It is not TGA, TGC, or TGT. Each of these letters represent one rung of the spiraling DNA ladder. It is mind-blowing that we ever figured this out! It is unimaginable that this is not God’s alphabet. No amount of time could accidentally produce such a perfect result.

    3. You say,

      “The likelihood of these events having occurred randomly seems very small, but there was indeed a very long time, over a billion years, over which they could occur.”

      There is no need to jump in with a “a teleological principle”.

      I agree with the last sentence in your comment — no, spontaneous development of a Krebs cycle has not been observed in a laboratory. But is this an argument? How many billions of years does the lab have to keep functioning before you can say it couldn’t possibly happen? Can you think of the immense electric bill that the university would run up? Not to mention the problems of overtime and tenure!

    4. Captcrisis you have perpetrated a straw man. I wrote “it’s more than knowing the ins-and-outs of a Krebs cycle.” That was in the context of saying one did not have to be an expert in a field to judge whether the scientific requirements for validation had been met.
      The point is not that scientists have not, ab initio, generated biochemical enzymatic cycles in the laboratory. I’ll repeat: the point is that they have not been able to set up experiments in which the building blocks were spontaneously generated from chemicals present in earth long ago under conditions then, nor spontaneous generation of all biopolymers from these building blocks, nor spontaneous generation of self-reproducing, metabolizing cells from these biopolymers.
      So they have proposed various scenarios for how life began without outside intervention, abiogenesis, but none of these scenarios have been empirically validated.

    5. Computational Chemisty is the field used for this type of work. It uses the most advanced super-computers which themselves cost a fortune to rent by the hour. The number of calculations per second I can’t even pronounce, but they have saved us from any further nuclear bomb testing (nuclear physics).

    6. It’s very odd to say that something might take a billion years and then point to the fact that scientists haven’t been able to replicate it in a lab in a few hours. That really proves nothing.

    7. No, Captcrisis, it isn’t odd. That’s how science works: empirical verification by observation and/or experiment. And in the birth and evolution of the universe, processes that took a billion years to occur were verified by observation. This is why string theory isn’t science; as Voit put it, “It isn’t even wrong!” Because it can’t be verified empirically (either for practical or intrinsic reasons.
      So theories about abiogenesis might seem reasonable, elegant, whatever. But if they can’t be tested–if they aren’t falsifiable–they’re not science, they’re something else. And that empirical verification is either by replicable experiments or by replicable observations. To repeat, and this is something non-scientists (and some scientists) don’t appreciate, this is how science works.

  1. I do not believe it is possible to explain supernatural origins in any natural way. To suggest that the Prime Mover used “little nudges at appropriate instances, or by some general mechanism He installs at the beginning,” is a disservice to the Word of God. The Scriptures are emphatic that God created the heavens and the earth and all things living on the earth with his “Word.” Jesus explains the same thing (Mk. 11: 23-25). “We walk by faith, not by sight (2 Cor. 5:7) – “Sight” is the empirical, provable, scientific methods necessary to prove something true with scientific means. Faith transcends sight. There are many more Scriptures. It is unlikely God would nudge something into being. All He needed to do was to say it. Romans 4: 17 – God “…gives life to the dead and call into being what does not exist,” (How? with His Word). Heb. 11:3 tells us that by faith “we understand that the universe was ordered by the word of God, so that what is visible came into being through the invisible.” – There is no empirical way to test for faith (the action word). Heb. 11:6, Without faith it is impossible to please God. We can not test for faith as we cannot test for a soul within the confines of the human body. In Christ’s love, Rich Van Kirk

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