Posted by: davidlarkin | August 11, 2008

Origins of Life

Miller/Urey Experiment

When I was in high school in the early 60s, I remember my zoology teacher telling us about the experiments done by scientists Miller and Urey in which they tried to create life from pre-biotic conditions, a primordial soup of chemicals, conditions they believed existed when life originated on earth. Stanley Miller, who did the experiments, was able to produce some amino acids, but was not able to combine those amino acids naturally to create the complex proteins necessary for life.

The study of the Origins of Life (“OOL”) is a research area of evolution science that has become stagnant. Today, very few scientists continue to try to create life on earth. Attempts to recreate the primordial soup of chemicals in the laboratory and with a spark of electricity create life in a test tube, as the media has portrayed the effort, have not been successful. Using a few sources, I have composed here a brief and admittedly skeptical summary of the modern history of origin of life theory and experimentation which describes the difficulties facing the OOL study today, as posed in large part by Stanley Miller himself.

In the early 1950s, Harold Urey proposed that the early pre-biotic earth had a “reducing atmosphere”

. . . since all of the outer planets in our solar system- Jupiter, Saturn, Uranus and Neptune- have this kind of atmosphere. A reducing atmosphere contains methane, ammonia, hydrogen and water. The Earth is clearly special in this respect, in that it contains an oxygen atmosphere which is clearly of biological origin.

from a 1996 interview with Urey’s collaborator, Stanley Miller (1930-2007).

Urey proposed experiments attempting to recreate the reducing atmosphere in the laboratory with electrical sparks simulating the lightning of the theoretical pre-biotic atmosphere. Stanley Miller was a graduate student working for Urey. He asked Urey if he could do the experiments. In Miller’s words:

The experiments were done in Urey’s lab when I was a graduate student. Urey gave a lecture in October of 1951 when I first arrived at Chicago and suggested that someone do these experiments. So I went to him and said, “I’d like to do those experiments”. The first thing he tried to do was talk me out of it. Then he realized I was determined. He said the problem was that it was really a very risky experiment and probably wouldn’t work, and he was responsible that I get a degree in three years or so. So we agreed to give it six months or a year. If it worked out fine, if not, on to something else. As it turned out I got some results in a matter of weeks.

Here is an account of the experiments taken from Leslie Orgel’s Scientific American article “The Origin of Life on Earth” (Scientific American, October, 1994) which is included in the 1996 Miller interview article:

In the early 1950s Stanley L. Miller, working in the laboratory of Harold C. Urey at the University of Chicago, did the first experiment designed to clarify the chemical reactions that occurred on the primitive earth. In the flask at the bottom, he created an “ocean” of water, which he heated, forcing water vapor to circulate through the apparatus. The flask at the top contained an “atmosphere” consisting of methane (CH4), ammonia (NH3), hydrogen (H2) and the circulating water vapor.

Next he exposed the gases to a continuous electrical discharge (“lightning”), causing the gases to interact. Water-soluble products of those reactions then passed through a condenser and dissolved in the mock ocean. The experiment yielded many amino acids and enabled Miller to explain how they had formed. For instance, glycine appeared after reactions in the atmosphere produced simple compounds – formaldehyde and hydrogen cyanide. Years after this experiment, a meteorite that struck near Murchison, Australia, was shown to contain a number of the same amino acids that Miller identified and in roughly the same relative amounts. Such coincidences lent credence to the idea that Miller’s protocol approximated the chemistry of the prebiotic earth. More recent findings have cast some doubt on that conclusion.

Miller’s experiment yielded organic compounds including amino acids, the building blocks of life, and catapulted a field of study known as exobiology into the headlines. But the additional steps needed to create life are a significant roadblock to success, and are not well known to the public. Miller himself was not sanguine about the prospects of making those additional steps in the laboratory. As one commentator, Casey Luskin, who took an OOL seminar from Miller, recently wrote:

OOL theorists often dramatically oversimplify how life started when talking to the public. The famous origin of life researcher Stanley Miller, however, has been more candid in some of his statements. At an origin-of-life seminar I took from him during my undergraduate studies at University of California, San Diego, Miller plainly taught us that “making compounds and making life are two different things.” Elsewhere Miller reportedly made a similar admission:

“Even Miller throws up his hands at certain aspects of it. The first step, making the monomers, that’s easy. We understand it pretty well. But then you have to make the first self-replicating polymers. That’s very easy, he says, the sarcasm fairly dripping. Just like it’s easy to make money in the stock market–all you have to do is buy low and sell high. He laughs. Nobody knows how it’s done.”(Peter Radetsky, “How Did Life Start?” Discover Magazine at http://discovermagazine.com/1992/nov/howdidlifestart153/)

During the seminar class I took from Miller, he outlined various specific steps that would be necessary to originate life:

1. Pre-biotic synthesis and the generating of a “primordial soup”
2. Polymerization of pre-biotic monomers into larger molecules.
3. Origin of a self-replicating molecule (“Pre-RNA World”)
4. Evolution of the “RNA World”
5. Evolution of the “DNA / Protein World”
6. Origin of Proto-cells

There are problems with each of these steps, but for now I’d just like to highlight the major problem with steps 3 & 4.

Steps 3 or 4 maintain that sometime during the origin of life, there arose an RNA molecule, or pre-RNA information-bearing molecule, that was able to clone itself. If there are occasional mistakes in the replication process, those that are better able to survive and replicate tend to make more copies, and so on, and Darwinian evolution evolves it the rest of the way.

This origin-of-life hypothesis is implausible for a few reasons: Aside from the fact that chemists have not been able to synthesize RNA or an RNA-like information-bearing molecule under natural conditions and that we’ve never observed such a molecule that can adequately clone itself, the odds of getting just the right sequence of nucleotides to create a self-cloning RNA molecule is astronomically low. Even if we assume a sea of randomly sequenced RNA molecules, since there are no physical or chemical laws that mandate the order of nucleotide bases in RNA, the odds of getting a useless sequence are just the same as getting the right one. These all represent astronomically improbable events.

Imagine trying to order a relatively short RNA molecule — 200 nucleotide bases — just right, so that self-replication can occur — by pure chance and sheer luck. The odds are 1 / 4^200. This is what ID folks like to call the “Information Sequence Problem”: Making chemicals might be possible, but how do you generate the information required for life? This question confounds origin of life theorists because they do not accept that new information comes from an intelligent cause. Dr. Stephen C. Meyer explains this:

[T]he need to explain the origin of specified information created an intractable dilemma for Oparin. On the one hand, if he invoked natural selection late in his scenario, he would need to rely on chance alone to produce the highly complex and specified biomolecules necessary to self-replication. On the other hand, if Oparin invoked natural selection earlier in the process of chemical evolution, before functional specificity in biomacromolecules would have arisen, he could give no account of how such prebiotic natural selection could even function (given the phenomenon of error-catastrophe). Natural selection presupposes a self-replication system, but self-replication requires functioning nucleic acids and proteins (or molecules approaching their complexity)—the very entities that Oparin needed to explain. Thus, Dobzhansky would insist that, “prebiological natural selection is a contradiction in terms.” … As noted above, the improbability of developing a functionally integrated replication system vastly exceeds the improbability of developing the protein or DNA components of such a system. Given the huge improbability and the high functional threshold it implies, many origin-of-life researchers came to regard prebiotic natural selection as both inadequate and essentially indistinguishable from appeals to chance.(Stephen C. Meyer, “DNA and the Origin of Life: Information, Specification, and Explanation,” pg. 246, Darwinism Design and Public Education (edited by Stephen C. Meyer and John Angus Campbell, 2004).)

As Meyer’s article concludes:

“Experience affirms that specified complexity or information … routinely arises from the activity of intelligent agents. A computer user who traces the information on a screen back to its source invariably comes to a mind, that of a software engineer or programmer. Similarly, the information in a book or newspaper column ultimately derives from a writer—from a mental, rather than a strictly material, cause. Further, our experience-based knowledge of information-flow confirms that systems with large amounts of specified complexity or information (especially codes and languages) invariably originate from an intelligent source—that is, from a mind or a personal agent.” (Ibid., pg. 262)

Thus life far more complex than “just add water,” because adding water–or any other chemicals–will not magically generate the specified and complex information in life. In fact, we cannot understand how the information in life originated apart from understanding intelligent causes.

Taking a different approach, OOL researchers and astrobiologists find it much easier to just assume that life — complete with its information-rich order — can and does arise through blind chemical processes. And they know they’re right, because they must be right, for life exists.

from Luskin, The Implications of the Hypothetical Discovery of Martian Life for Intelligent Design

As a result of the standstill in OOL research, the apparent slim probability of success, and as an alternative to the origin of life on earth, a theory of panspermia, a the theory that life always existed in the universe and was transported to earth via meteor, has been promoted. Richard Dawkins endorsed panspermia as a possible solution to the riddle of the origin of life in an interview with Ben Stein in Stein’s film Expelled. Sir Frederick Hoyle (1915-2001), the British astronomer and science fiction writer became notorious for proposing this. From Wikipedia:

In his later years, Hoyle became a staunch critic of theories of chemical evolution used to explain the naturalistic origin of life. With Chandra Wickramasinghe, Hoyle promoted the theory that life evolved in space, spreading through the universe via panspermia, and that evolution on earth is driven by a steady influx of viruses arriving via comets. In 1982, Hoyle presented Evolution from Space for the Royal Institution’s Omni Lecture. After considering the very remote probability of evolution he concluded:

“ If one proceeds directly and straightforwardly in this matter, without being deflected by a fear of incurring the wrath of scientific opinion, one arrives at the conclusion that biomaterials with their amazing measure or order must be the outcome of intelligent design. No other possibility I have been able to think of… ”

Published in his 1982/1984 books Evolution from Space (co-authored with Chandra Wickramasinghe), Hoyle calculated that the chance of obtaining the required set of enzymes for even the simplest living cell was one in 10^40,000th. Since the number of atoms in the known universe is infinitesimally tiny by comparison (10^80th), he argued that even a whole universe full of primordial soup would grant little chance to evolutionary processes. He claimed:

The notion that not only the biopolymer but the operating program of a living cell could be arrived at by chance in a primordial organic soup here on the Earth is evidently nonsense of a high order.

Hoyle compared the random emergence of even the simplest cell to the likelihood that “a tornado sweeping through a junk-yard might assemble a Boeing 747 from the materials therein.” Hoyle also compared the chance of obtaining even a single functioning protein by chance combination of amino acids to a solar system full of blind men solving Rubik’s Cube simultaneously.

Even if you propose that life originated elsewhere, or as Dawkins has proposed, intelligent life exists somewhere in the universe which had the ability to seed the earth with life, you are nevertheless stuck with the problem of the origin of that extraterrestrial life and the source of its origin, and on and on. This problem of infinite regression was well stated by Stephen Hawking in his 1988 book A Brief History of Time, which begins in Chapter 1:

A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: “What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise.” The scientist gave a superior smile before replying, “What is the tortoise standing on?” “You’re very clever, young man, very clever,” said the old lady. “But it’s turtles all the way down!”

The lack of success in OOL has limited scientific interest and apparently limited its funding. OOL is subsumed in the scientific field of “exobiology.” In the 1996 interview with Stanley Miller cited above, when asked about the current state of research in exobiology and OOL, Miller said:

The term exobiology was coined by Nobel Prize winning scientist Joshua Lederberg. What it means is the study of life beyond the Earth. But since there’s no known life beyond the Earth people say its a subject with no subject matter. It refers to the search for life elsewhere, Mars, the satellites of Jupiter and in other solar systems. It is also used to describe studies of the origin of life on Earth, that is, the study of pre-biotic Earth and what chemical reactions might have taken place as the setting for life’s origin.

. . . It is a very small field. There is a society, the International Society for the Study of the Origin of Life. It has only 300 members, a rather small society.

By it own terms, science cannot simply adopt its creation story on faith. It must provide some verification of the truth of its story using the methods of science. Yet, it is assumed by many who rely on the materialist evolution story that life must have originated through some sort of random action of material particles in fields of force billions of years ago. Looking at the history of OOL research and the probabilities associated with the story, for those who assume it to be so, it is a matter of faith, not science.

Related Posts
Stephen Jay Gould’s Dissent
Vladimir Nabokov – “Furious” Darwin Doubter
Who’s a Leftist Creationist

Advertisements

Responses

  1. Not that I’m impressed a lot, but this is a lot more than I expected for when I stumpled upon a link on Digg telling that the info is quite decent. Thanks.

  2. They did it! http://online.wsj.com/article/SB10001424052748703559004575256470152341984.html?mod=WSJ_hps_MIDDLETopStories

    • No, they didn’t. They did not start from scratch with random inorganic molecules. They had a plan. The problem of “origin of life” is to get there from a pool of inorganic molecules, and for it to be natural, there must be a hidden auto-mechanism, since science has given up on random creation of life as beyond the scope of probability in the limited time available.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: