Tag Archives: Origin of Life

Does the Miller-Urey experiment tell us anything about how life originated on Earth?

Do the Miller-Urey experiments simulate the early Earth?
The Miller-Urey experiments

There are two problems related to the origin of the first living cell, on atheism:

  1. The problem of getting the building blocks needed to create life – i.e. the amino acids
  2. The problem of creating the functional sequences of amino acids and proteins that can support the minimal operations of a simple living cell

Normally, I concede the first problem and grant the atheist all the building blocks he needs. This is because step 2 is impossible. There is no way, on atheism, to form the sequences of amino acids that will fold up into proteins, and then to form the sequences of proteins that can be used to form everything else in the cell, including the DNA itself.

Today, let’s take a look at the problems with step 1.

The problem of getting the building blocks of life

Now you may have heard that some scientists managed to spark some gasses to generate most of the 20 amino acids found in living systems. These experiments are called the “Miller-Urey” experiments.

The IDEA center has a nice summary of origin-of-life research that explains a few of the main problems with step 1.

Miler and Urey used the wrong gasses:

Miller’s experiment requires a reducing methane and ammonia atmosphere,11, 12 however geochemical evidence says the atmosphere was hydrogen, water, and carbon dioxide (non-reducing).15, 16 The only amino acid produced in a such an atmosphere is glycine (and only when the hydrogen content is unreasonably high), and could not form the necessary building blocks of life.11

Miller and Urey didn’t account for UV of molecular instability:

Not only would UV radiation destroy any molecules that were made, but their own short lifespans would also greatly limit their numbers. For example, at 100ºC (boiling point of water), the half lives of the nucleic acids Adenine and Guanine are 1 year, uracil is 12 years, and cytozine is 19 days20 (nucleic acids and other important proteins such as chlorophyll and hemoglobin have never been synthesized in origin-of-life type experiments19).

Miller and Urey didn’t account for molecular oxygen:

We all have know ozone in the upper atmosphere protects life from harmful UV radiation. However, ozone is composed of oxygen which is the very gas that Stanley Miller-type experiments avoided, for it prevents the synthesis of organic molecules like the ones obtained from the experiments! Pre-biotic synthesis is in a “damned if you do, damned if you don’t” scenario. The chemistry does not work if there is oxygen because the atmosphere would be non-reducing, but if there is no UV-light-blocking oxygen (i.e. ozone – O3) in the atmosphere, the amino acids would be quickly destroyed by extremely high amounts of UV light (which would have been 100 times stronger than today on the early earth).20, 21, 22 This radiation could destroy methane within a few tens of years,23 and atmospheric ammonia within 30,000 years.15

And there were three other problems too:

At best the processes would likely create a dilute “thin soup,”24 destroyed by meteorite impacts every 10 million years.20, 25 This severely limits the time available to create pre-biotic chemicals and allow for the OOL.

Chemically speaking, life uses only “left-handed” (“L”) amino acids and “right-handed” (“R)” genetic molecules. This is called “chirality,” and any account of the origin of life must somehow explain the origin of chirality. Nearly all chemical reactions produce “racemic” mixtures–mixtures with products that are 50% L and 50% R.

Two more problems are not mentioned in the article. A non-peptide bond anywhere in the chain will ruin the chain. You need around 200 amino acids to make a protein. If any of the bonds is not a peptide bond, the chain will not work in a living system. Additionally, the article does not mention the need for the experimenter to intervene in order to prevent interfering cross-reactions that would prevent the amino acids from forming.

Now keep in mind that even if you get the building blocks, you are left with the sequencing problem. Like the letters of the words in this blog post, the building blocks of life also need to be put in a meaningful sequence in order to do work in a living system – but that’s another topic for another day.

Dr. Walter Bradley lectures on scientific evidence the creation and design of the universe

This lecture is special to me, because I bought a VHS tape of it just after I started working full-time, and watched it a million times. A lot of people come to their convictions about God’s existence because of parents or church or intuitions, but for me it’s all about the scientific evidence. This lecture changed my life. I wish more people taught their children about this evidence! This lecture was delivered at the University of California, Santa Barbara.

About the speaker:

Dr. Bradley received his B.S. in Engineering Science and his Ph.D. in Materials Science from the University of Texas in Austin.

Dr. Bradley taught for eight years at the Colorado School of Mines before assuming a position as Professor of Mechanical Engineering at Texas A&M University (TAMU) in 1976.

During his 24 years at Texas A&M, Dr. Bradley served as Head of the Department of Mechanical Engineering at Texas A&M University and as Director of the Polymer Technology Center, and received five College of Engineering Research Awards. He has received over $4,500,000 in research grants and has published over 140 technical articles and book chapters. He has also co-authored “The Mystery Of Life’s Origin: Reassessing Current Theories. He is a Fellow of the American Society for Materials and of the American Scientific Affiliation and serves as a consultant for many Fortune 500 companies.

He currently serves as Distinguished Professor of Engineering at Baylor University.

The lecture: (63 minutes lecture, 25 minutes audience Q&A)

Summary slide:

This slide summarizes the content of the lecture
This slide summarizes the content of the lecture

Introduction:

  • At the beginning of the 20th century, people believed that the progress of science was pointing away from an intelligent Creator and Designer, and towards naturalism
  • A stream of new discoveries has shifted the support of science towards theism, and away from naturalism
  • Richard Dawkins, an atheist, says that nature only has the appearance of design, but that if you look closer, naturalistic mechanisms can account for the appearance of design
  • When deciding between design and apparent design (“designoid”), it matters whether you think there is an intelligence there to do the designing

Evidence #1: The Big Bang:

  • an eternal “steady state” universe is more compatible with naturalism, but a created universe is more compatible with a Creator
  • In 1929, Hubble used telescopes to observe that the light from distant galaxies was redshifted. The further away galaxies were, the faster they were moving away. Therefore, space is expanding in all directions, suggesting an explosive origin of the universe
  • In 1965, the discovery of the cosmic microwave background radiation matched a prediction of the Big Bang cosmology, and of the creation event
  • In 1992, the COBE space telescope allowed us to test four specific predictions of the Big Bang model, especially the predictions for light element abundances (hydrogen and helium), which matched the predictions of the creation model

Evidence #2: Simple mathematical structure of the physical laws

  • the simple mathematical structure of natural laws allows us to understand these laws, make discoveries, and engineer solutions to problems
  • early scientists saw the mathematical structure of the universe to mean that nature was designed by an intelligent to be understood
  • the fundamental equations of the laws of the universe can be easily written on one side of one sheet of paper
  • Eugene Wigner’s famous paper, “The Unreasonable Effectiveness of Mathematics in the Physical Sciences” makes the point that this simple structure is an unexpected gift that allows is to do science

Evidence #3: fine-tuning of the physical constants and quantities

  • in order for any kind of complex life to survive, we need stars that provide energy within specific ranges for long periods of time
  • in order for any kind of complex life to survive, we need planets with stable orbits that will not suffer from extreme temperature swings as it varies in distance from its star
  • in order for any kind of complex life to survive, we need stable atomic structure
  • in order for any kind of complex life to survive, we need to have chemical diversity and correct relative abundances of each element
  • organic life has minimum requirements: process energy, store information, replicate, and you can’t fulfill those functions if there is only one element, e.g. – hydrogen
  • the energy level from the photons from the sun have to match the energy levels of the different elements in order to drive the chemical bonding needed for life
  • These requirements for life of any imaginable type depend on the values of the constants and quantities. The constants and quantities cannot vary much from what they are, or the universe will lose the characteristics (above) that allow it to support complex life of any imaginable time
  • For example, ratio of strong force to electromagnetic force:
    – if 2% larger, then no stable hydrogen, no long-lived stars, no compounds containing hydrogen, e.g. – water
    – if 5% smaller, no stable stars, heavy hydrogen would be unstable, few elements other than hydrogen

Evidence #4: initial conditions for habitability

  • Universe: expansion rate of the universe must be fast enough to avoid a re-collapse, but slow enough to allow matter to clump together and form stars and planets for complex life to live on
  • Planet: right distance from the star to get the right climate
  • Planet: right mass to retain the right atmosphere

Evidence #5: origin of life and information theory

  • It’s possible to explain every process in an automobile engine using plain old naturalistic mechanisms – no supernatural explanation is necessary to understand the processes
  • But the existence of engine itself: engineering all the parts has to be explained by the work of an intelligence
  • Similarly, we can understand how living systems work, but the existence of the living systems requires an intelligence
  • Even the simplest living system has to perform minimal function: capture energy, store information and replicate
  • Living systems are composed of objects like proteins that are composed of sequences of components complex such that the order of the components gives the overall structure function
  • Developing the components for a simple living cell is very improbable – even given the large number of galaxies, stars and planets in the universe, it is unlikely that complex, embodied life would exist anywhere in the universe

Evidence #6: more initial conditions for habitability

  • Location within the galaxy: you need to be away from the center of the galaxy, because the explosions from dying stars, and excessive radiation will kill life
  • Location within the galaxy: you need to be close enough to the center in order catch the heavy elements you need for life from the explosions of other stars
  • Location within the galaxy: the best location is between two arms of  a spiral galaxy, where you can get the heavy elements you need from dying stars, but without being hit with explosions and harmful radiation
  • Star mass: determines rate at which the sun burns, determines the energy level of photons that are used to drive chemical bonding reactions, determines the length of time the star will be stable
  • Star mass: star mass must be the correct value in order to allow liquid water on the planet’s surface, while still preserving stable orbit

I wish there was more curiosity about science in churches, and young Christians understood how critical science is for grounding the rationality of the Christian worldview. We need to be training up more scientists who think about the big questions, like Dr. Walter Bradley.

Yale University computer science professor takes a look at protein formation probabilities

How did life begin?
How did life begin?

When I was in graduate school, we studied a book called “Mirror Worlds”, authored by famous computer science professor David Gelernter at Yale University. This week, I noticed that Dr. Gelernter had written an article in the prestigious Claremont Review of Books. In his article, he applies his knowledge of computer science to the problem of the origin of life.

Evolution, if it is going to work at all, has to explain the problem of how the basic building blocks of life – proteins – can emerge from non-living matter. It turns out that the problem of the origin of life is essentially a problem of information – of code. If the components of proteins are ordered properly, then the sequence folds up into a protein that has biological function. If the sequence is not good, then just like computer code, it won’t run.

Here’s Dr. Gelernter to explain:

How to make proteins is our first question. Proteins are chains: linear sequences of atom-groups, each bonded to the next. A protein molecule is based on a chain of amino acids; 150 elements is a “modest-sized” chain; the average is 250. Each link is chosen, ordinarily, from one of 20 amino acids. A chain of amino acids is a polypeptide—“peptide” being the type of chemical bond that joins one amino acid to the next. But this chain is only the starting point: chemical forces among the links make parts of the chain twist themselves into helices; others straighten out, and then, sometimes, jackknife repeatedly, like a carpenter’s rule, into flat sheets. Then the whole assemblage folds itself up like a complex sheet of origami paper. And the actual 3-D shape of the resulting molecule is (as I have said) important.

Imagine a 150-element protein as a chain of 150 beads, each bead chosen from 20 varieties. But: only certain chains will work. Only certain bead combinations will form themselves into stable, useful, well-shaped proteins.

So how hard is it to build a useful, well-shaped protein? Can you throw a bunch of amino acids together and assume that you will get something good? Or must you choose each element of the chain with painstaking care? It happens to be very hard to choose the right beads.

Gelernter decides to spot the Darwinist a random sequence of 150 elements. Now the task the Darwinist is to use random mutation to arrive at a sequence of 150 links that has biological function.

[W]hat are the chances that a random 150-link sequence will create such a protein? Nonsense sequences are essentially random. Mutations are random. Make random changes to a random sequence and you get another random sequence. So, close your eyes, make 150 random choices from your 20 bead boxes and string up your beads in the order in which you chose them. What are the odds that you will come up with a useful new protein?

[…]The total count of possible 150-link chains, where each link is chosen separately from 20 amino acids, is 20150. In other words, many. 20150 roughly equals 10195, and there are only 1080 atoms in the universe.

What proportion of these many polypeptides are useful proteins? Douglas Axe did a series of experiments to estimate how many 150-long chains are capable of stable folds—of reaching the final step in the protein-creation process (the folding) and of holding their shapes long enough to be useful. (Axe is a distinguished biologist with five-star breeding: he was a graduate student at Caltech, then joined the Centre for Protein Engineering at Cambridge. The biologists whose work Meyer discusses are mainly first-rate Establishment scientists.) He estimated that, of all 150-link amino acid sequences, 1 in 1074 will be capable of folding into a stable protein. To say that your chances are 1 in 1074 is no different, in practice, from saying that they are zero. It’s not surprising that your chances of hitting a stable protein that performs some useful function, and might therefore play a part in evolution, are even smaller. Axe puts them at 1 in 1077.

In other words: immense is so big, and tiny is so small, that neo-Darwinian evolution is—so far—a dead loss. Try to mutate your way from 150 links of gibberish to a working, useful protein and you are guaranteed to fail. Try it with ten mutations, a thousand, a million—you fail. The odds bury you. It can’t be done.

Keep in mind that you need many, many proteins in order to have even a simple living cell. (And that’s not even considering the problem of organizing the proteins into a system).

So, if you’re a naturalist, then your only resources to explain the origin of life are chance and mutation. As Dr. Gelernter shows, naturalistic explanations won’t work to solve even part of the problem. Not even with a long period of time.  Not even if you use the entire universe as one big primordial soup, and keep trying sequences for the history of the universe. It just isn’t possible to arrive at sequences that have biological function in the time available, using the resources available. The only viable explanation is that there is a computer scientist who wrote the code without using trial and error. Something that ordinary software engineers like myself and Dr. Gelernter do all the time. We know what kind of cause is adequate to explain functioning code.