Tag Archives: Protein

New software calculates the probability of generating functional proteins by chance

Apologetics and the progress of science
Apologetics and the progress of science

Here’s an article sent to me by JoeCoder about a new computer program written by Kirk Durston.

About Kirk:

Kirk Durston is a scientist, a philosopher, and a clergyman with a Ph.D. in Biophysics, an M.A. in Philosophy, a B.Sc. in Mechanical Engineering, and a B.Sc. in Physics. His work involves a significant amount of time thinking, writing and speaking about the interaction of science, theology and philosophy within the context of authentic Christianity. He has been married for 34 years to Patti and they have six children and three grandchildren. He enjoys landscape photography, antiques of various types, wilderness canoeing and camping, fly fishing, amateur astronomy, reading, music, playing the saxophone (alto), and enjoying family and friends.

Kirk grew up on a cattle and grain farm in central Manitoba, Canada, where he spent countless hours wandering around on his own in the forest as a young boy, fascinated with the plants and animals that are native to that region of the province. Throughout his teen years he spent six days a week in the summer working as a farm hand with cattle and grain. He left his father’s farm at the age of 19 to go to university.

Canada? Can anything good come out of Canada? Oh well, at least he’s not from Scotland. Anyway, on to the research, that’s what we care about. Code!

Summary of the article:

  • Biological life requires proteins
  • Proteins are sequences of amino acids, chained together
  • the order of amino acids determines whether the sequence has biological function
  • sequences that have biological function are rare, compared to the total number of possible sequences
  • Durston wrote a program to calculate the number of the probability of getting a functional sequence by random chance
  • The probability for getting a functional protein by chance is incredibly low

With that said, we can understand what he wrote:

This program can compute an upper limit for the probability of obtaining a protein family from a wealth of actual data contained in the Pfam database. The first step computes the lower limit for the functional complexity or functional information required to code for a particular protein family, using a method published by Durston et al. This value for I(Ex) can then be plugged into an equation published by Hazen et al. in order to solve the probability M(Ex)/N of ‘finding’ a functional sequence in a single trial.

I downloaded 3,751 aligned sequences for the Ribosomal S7 domain, part of a universal protein essential for all life. When the data was run through the program, it revealed that the lower limit for the amount of functional information required to code for this domain is 332 Fits (Functional Bits). The extreme upper limit for the number of sequences that might be functional for this domain is around 10^92. In a single trial, the probability of obtaining a sequence that would be functional for the Ribosomal S7 domain is 1 chance in 10^100 … and this is only for a 148 amino acid structural domain, much smaller than an average protein.

For another example, I downloaded 4,986 aligned sequences for the ABC-3 family of proteins and ran it through the program. The results indicate that the probability of obtaining, in a single trial, a functional ABC-3 sequence is around 1 chance in 10^128. This method ignores pairwise and higher order relationships within the sequence that would vastly limit the number of functional sequences by many orders of magnitude, reducing the probability even further by many orders of magnitude – so this gives us a best-case estimate.

There are only about 10^80 particles in the entire physical universe – 10^85 at the most. These are long odds. But maybe if we expand the probabilistic resources by buying more slot machines, and we pull the slot machine lever at much faster rate… can we win the jackpot then?

Nope:

What are the implications of these results, obtained from actual data, for the fundamental prediction of neo-Darwinian theory mentioned above? If we assume 10^30 life forms with a fast replication rate of 30 minutes and a huge genome with a very high mutation rate over a period of 10 billion years, an extreme upper limit for the total number of mutations for all of life’s history would be around 10^43. Unfortunately, a protein domain such as Ribosomal S7 would require a minimum average of 10^100 trials, about 10^57 trials more than the entire theoretical history of life could provide – and this is only for one domain. Forget about ‘finding’ an average sized protein, not to mention thousands.

So even if you have lots of probabilistic resources, and lots of time, you’re still not going to get your protein.

Compare these numbers with the 1 in 10^77 number that I posted about yesterday from Doug Axe. There is just no way to account for proteins if there is no intelligent agent to place the amino acids in sequence. When it comes to writing code, writing blog posts, writing music, or placing Scrabble letters, you need an intelligence. Sequencing amino acids into proteins? You need an intelligence.

How likely is it for blind forces to sequence a functional protein by chance?

Apologetics and the progress of science
Apologetics and the progress of science

How likely is it that you could swish together amino acids randomly and come up with a sequence that would fold up into a functional protein?

Evolution News reports on research performed by Doug Axe at Cambridge University, and published in the peer-reviewed Journal of Molecular Biology.

Excerpt:

Doug Axe’s research likewise studies genes that it turns out show great evidence of design. Axe studied the sensitivities of protein function to mutations. In these “mutational sensitivity” tests, Dr. Axe mutated certain amino acids in various proteins, or studied the differences between similar proteins, to see how mutations or changes affected their ability to function properly.10 He found that protein function was highly sensitive to mutation, and that proteins are not very tolerant to changes in their amino acid sequences. In other words, when you mutate, tweak, or change these proteins slightly, they stopped working. In one of his papers, he thus concludes that “functional folds require highly extraordinary sequences,” and that functional protein folds “may be as low as 1 in 10^77.”11 The extreme unlikelihood of finding functional proteins has important implications for intelligent design.

Just so you know, those footnotes say this:

[10.] Douglas D. Axe, “Estimating the Prevalence of Protein Sequences Adopting Functional Enzyme Folds,” Journal of Molecular Biology, 1-21 (2004); Douglas D. Axe, “Extreme Functional Sensitivity to Conservative Amino Acid Changes on Enzyme Exteriors,” Journal of Molecular Biology, Vol. 301:585-595 (2000).

[11.] Douglas D. Axe, “Estimating the Prevalence of Protein Sequences Adopting Functional Enzyme Folds,” Journal of Molecular Biology, 1-21 (2004).

And remember, you need a lot more than just 1 protein in order to create even the simplest living system. Can you generate that many proteins in the short time between when the Earth cools and the first living cells appear? Even if we spot the naturalist a prebiotic soup as big as the universe, and try to make sequences as fast as possible, it’s unlikely to generate even one protein in the time before first life appears.

Here’s Doug Axe to explain his research:

If you are building a protein for the FIRST TIME, you have to get it right all at once – not by building up to it gradually using supposed Darwinian mechanisms. That’s because there is no replication before you have the first replicator. The first replicator cannot rely on explanations that require replication to already be in place.

The importance of having a narrative when confronting the assumption of naturalism

Apologetics and the progress of science
Apologetics and the progress of science

How do you present theism as a rational belief to a person who thinks that the progress of science has removed the need for God?

Canadian science writer Denyse O’Leary writes about the history of cosmology at Evolution News.

Excerpt:

What help has materialism been in understanding the universe’s beginnings?

Many in cosmology have never made any secret of their dislike of the Big Bang, the generally accepted start to our universe first suggested by Belgian priest Georges Lemaître (1894-1966).

On the face of it, that is odd. The theory accounts well enough for the evidence. Nothing ever completely accounts for all the evidence, of course, because evidence is always changing a bit. But the Big Bang has enabled accurate prediction.

In which case, its hostile reception might surprise you. British astronomer Fred Hoyle (1915-2001) gave the theory its name in one of his papers — as a joke. Another noted astronomer, Arthur Eddington (1882-1944), exclaimed in 1933, “I feel almost an indignation that anyone should believe in it — except myself.” Why? Because “The beginning seems to present insuperable difficulties unless we agree to look on it as frankly supernatural.”

One team of astrophysicists (1973) opined that it “involves a certain metaphysical aspect which may be either appealing or revolting.” Robert Jastrow (1925-2008), head of NASA’s Goddard Institute for Space Studies, initially remarked, “On both scientific and philosophical grounds, the concept of an eternal Universe seems more acceptable than the concept of a transient Universe that springs into being suddenly, and then fades slowly into darkness.” And Templeton Prize winner (2011) Martin Rees recalls his mentor Dennis Sciama’s dogged commitment to an eternal universe, no-Big Bang model:

For him, as for its inventors, it had a deep philosophical appeal — the universe existed, from everlasting to everlasting, in a uniquely self-consistent state. When conflicting evidence emerged, Sciama therefore sought a loophole (even an unlikely seeming one) rather as a defense lawyer clutches at any argument to rebut the prosecution case.

Evidence forced theorists to abandon their preferred eternal-universe model. From the mid 1940s, Hoyle attempted to disprove the theory he named. Until 1964, when his preferred theory, the Steady State, lost an evidence test.

Here is a quick summary of some of the experimental evidence that emerged in the last few decades that caused naturalists to abandon the eternal universe that they loved so much when they were younger.

The importance of having a narrative

Now I want to make a very, very important point about Christianity and the progress of science. And that point is that it is very important that Christians present the evidence in exactly the way that Denyse presented it in that article – in its historical context, featuring the conflict between naturalists and the experimental evidence.

All Christians should be familiar with the following basic pieces of evidence which fit the war between science and naturalism narrative:

  1. The origin of the universe
  2. The cosmic fine-tuning
  3. The origin of life (biological information)
  4. The sudden origin of the Cambrian phyla
  5. The habitability/observability correlation

When you talk about these evidences as a Christian theist to non-Christians, you have to have cultivated a genuine interest in reconciling your beliefs with science. You have to accept that there are two books that reveal God’s character and attributes. The book of nature, and the book of Scripture. And you need to be flexible about getting these two books to fit together. The book of nature gives us natural theology (see Romans 1). It tells us that God is Creator and Designer. The book of Scripture tells us that God stepped into history as a man to save us by taking the punishment for our headlong rush away from God, which the Bible calls sin. Science is one way that humans can recover some of basic knowledge about God. Knowledge that is only possible because God created and designed the universe (and us) in such a way that we are capable of making discoveries, and that the universe is capable of being explored and understood.

It’s very important to present these five basic evidences to non-Christians in the historical context. And here is the story you must tell: “In the beginning, there was the naturalism, and the naturalism tried to argue from ignorance that God was not Creator and God was not Designer. And then came the science, and now people have to give up their naturalism in order to not be crazy and irrational”. That’s the narrative you use when talking to non-Christians about science.

In the beginning was the naturalism:

  1. In pre-scientific times, atheists maintained that the universe was eternal
  2. In pre-scientific times, atheists maintained that a life-permitting universe was as likely as a life-prohibiting universe
  3. In pre-scientific times, atheists maintained that the cell was a simple blob of jello that could spontaneously emerge in some warm pond
  4. In pre-scientific times, atheists maintained that the sudden origin of the Cambrian phyla would be explained by subsequent fossil discoveries
  5. In pre-scientific times, atheists maintained that there was nothing special about our galaxy, solar system, planet or moon

But then science progressed by doing experiments and making observations:

  1. Scientists discovered redshift and the cosmic microwave background radiation (evidence for a cosmic beginning) and more!
  2. Scientists discovered the fine-tuning of gravity and of the cosmological constant and more!
  3. Scientists discovered protein sequencing and exposed the myth of “junk DNA” and more!
  4. Scientists discovered an even shorter Cambrian explosion period and the absence of precursor fossils and more!
  5. Scientists discovered galactic habitable zones and circumstellar habitable zones and more!

And now rational people – people who want to have true beliefs about reality – need to abandon a false religion (naturalism).

Now naturally, science is in a state of flux and things change. But you have to look at the trend of discoveries, and those trends are clearly going against naturalism, and in favor of Christian theism. No one is arguing for a deductive proof here, we are simply looking at the evidence we have today and proportioning our belief to the concrete evidence we have today. People who are guided by reason should not seek to construct a worldview by leveraging speculations about future discoveries and mere possibilities. We should instead believe what is more probable than not. That’s what a rational seeker of truth ought to do. Proportion belief to probabilities based on current, concrete knowledge.

Atheism, as a worldview, is not rooted in an honest assessment about what science tells us about reality. Atheism is rooted in a religion: naturalism. And the troubling thing we learn from looking at the history of science is that this religion of naturalism is insulated from correction from the progress of science. Nothing that science reveals about nature seems to be able to put a dent in the religion of naturalism, at least for most atheists.

It falls to us Christian theists, then, to hold them accountable for their abuse and misrepresentation of science. And that means telling the story of the progress of science accurately, and accurately calling out the religion of naturalism for what it is – a religion rooted in blind faith and ignorance that has been repeatedly and convincingly falsified by the progress of science in the modern era.

Positive arguments for Christian theism

Was early Earth’s atmosphere suitable for creating the building blocks of life?

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

Biochemist Dr. Fazale Rana of Reasons to Believe offers some evidence.

Excerpt:

Today, the Miller-Urey experiment is considered to be irrelevant to the origin-of-life question. Current understanding of the composition of early Earth’s atmosphere differs significantly from the gas mix used by Miller. Most planetary scientists now think that the Earth’s primeval atmosphere consisted of carbon dioxide, nitrogen, and water vapor. Laboratory experiments indicate that this gas mixture is incapable of yielding organic materials in Miller-Urey-type experiments.

In May 2003 origin-of-life researchers Jeffrey Bada and Antonio Lazcano, long-time associates of Miller, wrote an essay for Science (May 2, 2003, pp. 745-746)commemorating the 50-year anniversary of the publication of Miller’s initial results.They pointed out that the Miller-Urey experiment has historical significance, but not scientific importance in contemporary origin-of-life thought. Bada and Lazcano wrote:

Is the “prebiotic soup” theory a reasonable explanation for the emergence of life? Contemporary geoscientists tend to doubt that the primitive atmosphere had the highly reducing composition used by Miller in 1953.

In his book Biogenesis, origin-of-life researcher Noam Lahav passes similar judgment:

The prebiotic conditions assumed by Miller and Urey were essentially those of a reducing atmosphere. Under slightly reducing conditions, the Miller-Urey reaction does not produce amino acids, nor does it produce the chemicals that may serve as the predecessors of other important biopolymer building blocks. Thus, by challenging the assumption of a reducing atmosphere, we challenge the very existence of the “prebiotic soup”, with its richness of biologically important organic compounds.

For many people, the generation of amino acids from simple chemical compounds thought to be present in early Earth’s atmosphere meant that life could originate all on its own without the need for a Creator. Work done on the early planetary conditions of Earth in the intervening decades between Miller’s famous experiment and his death, however, have invalidated this famous experiment and its support for an evolutionary explanation for life’s origin, in spite of what textbooks report.

The IDEA Center has a nice summary of origin-of-life research that explains why scientists no longer accept the idea that the building blocks of life can be formed by sparking the gasses that were present on the early Earth.

Miler and Urey used the wrong gasses:

Miller’s experiment requires a reducing methane and ammonia atmosphere, however geochemical evidence says the atmosphere was hydrogen, water, and carbon dioxide (non-reducing). 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.

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 days (nucleic acids and other important proteins such as chlorophyll and hemoglobin have never been synthesized in origin-of-life type experiments).

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).This radiation could destroy methane within a few tens of years, and atmospheric ammonia within 30,000 years.

And there were three other problems too:

At best the processes would likely create a dilute “thin soup,” destroyed by meteorite impacts every 10 million years. 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. That’s another problem with the origin of life – experiments show that getting the building blocks requires an intelligence to intervene.

Now keep in mind that even if you get the building blocks, you are left with the sequencing problem – but that’s another topic for another day.

Walter Bradley: three scientific evidences that point to a designed universe

Dr. Walter L. Bradley
Dr. Walter L. Bradley

Dr. Walter L. Bradley (C.V. here) is the Distinguished Professor of Engineering at Baylor.

Here’s a bio:

Walter Bradley (B.S., Ph.D. University of Texas at Austin) is Distinguished Professor of Engineering at Baylor. He comes to Baylor from Texas A&M University where he helped develop a nationally recognized program in polymeric composite materials. At Texas A&M, he served as director of the Polymer Technology Center for 10 years and as Department Head of Mechanical Engineering, a department of 67 professors that was ranked as high as 12th nationally during his tenure. Bradley has authored over 150 refereed research publications including book chapters, articles in archival journals such as the Journal of Material Science, Journal of Reinforced Plastics and Composites, Mechanics of Time-Dependent Materials, Journal of Composites Technology and Research, Composite Science and Technology, Journal of Metals, Polymer Engineering and Science, and Journal of Materials Science, and refereed conference proceedings.

Dr. Bradley has secured over $5.0 million in research funding from NSF grants (15 yrs.), AFOSR (10 years), NASA grants (10 years), and DOE (3 years). He has also received research grants or contracts from many Fortune 500 companies, including Alcoa, Dow Chemical, DuPont, 3M, Shell, Exxon, Boeing, and Phillips.

He co-authored The Mystery of Life Origin: Reassessing Current Theories and has written 10 book chapters dealing with various faith science issues, a topic on which he speaks widely.

He has received 5 research awards at Texas A&M University and 1 national research award. He has also received two teaching awards. He is an Elected Fellow of the American Society for Materials and the American Scientific Affiliation (ASA), the largest organization of Christians in Science and Technology in the world. He is President elect of the ASA and will serve his term in 2008.

You can read more about his recent research in this article from Science Daily.

Below, I analyze a lecture entitled “Is There Scientific Evidence for an Intelligent Designer?”. Dr. Bradley explains how the progress of science has made the idea of a Creator and Designer of the universe more acceptable than ever before.

The MP3 file is here.

Evidence #1: The design of the universe

1. The correspondence of natural phenomena to mathematical law

  • All observations of physical phenomena in the universe, such as throwing a ball up in the air, are described by a few simple, elegant mathematical equations.

2. The fine-tuning of physical constants and rations between constants in order to provide a life-permitting universe

  • Life has certain minimal requirements; long-term stable source of energy, a large number of different chemical elements, an element that can serve as a hub for joining together other elements into compounds, etc.
  • In order to meet these minimal requirements, the physical constants, (such as the gravitational constant), and the ratios between physical constants, need to be withing a narrow range of values in order to support the minimal requirements for life of any kind.
  • Slight changes to any of the physical constants, or to the rations between the constants, will result in a universe inhospitable to life.
  • The range of possible ranges over 70 orders of magnitude.
  • Although each individual selection of constants and ratios is as unlikely as any other selection, the vast majority of these possibilities do not support the minimal requirements of life of any kind. (In the same way as any hand of 5 cards that is dealt is as likely as any other, but you are overwhelmingly likely NOT to get a royal flush. In our case, a royal flush is a life-permitting universe).

Examples of finely-tuned constants and ratios: (there are more examples in the lecture)

a) The strong force: (the force that binds nucleons (= protons and neutrons) together in nucleus, by means of meson exchange)

  • if the strong force constant were 2% stronger, there would be no stable hydrogen, no long-lived stars, no hydrogen containing compounds. This is because the single proton in hydrogen would want to stick to something else so badly that there would be no hydrogen left!
  • if the strong force constant were 5% weaker, there would be no stable stars, few (if any) elements besides hydrogen. This is because you would NOT be able to build up the nuclei of the heavier elements, which contain more than 1 proton.
  • So, whether you adjust the strong force up or down, you lose stars than can serve as long-term sources of stable energy, or you lose chemical diversity, which is necessary to make beings that can perform the minimal requirements of living beings. (see below)

b) The conversion of beryllium to carbon, and carbon to oxygen

  • Life requires carbon in order to serve as the hub for complex molecules, but it also requires oxygen in order to create water.
  • Carbon is like the hub wheel in a tinker toy set: you can bind other elements together to more complicated molecules (e.g. – “carbon-based life), but the bonds are not so tight that they can’t be broken down again later to make something else.
  • The carbon resonance level is determined by two constants: the strong force and electromagnetic force.
  • If you mess with these forces even slightly, you either lose the carbon or the oxygen.

3. Fine-tuning to allow a habitable planet

  • A number of factors must be fine-tuned in order to have a planet that supports life
  • Initial estimates predicted abundant life in the universe, but revised estimates now predict that life is almost certainly unique in the galaxy, and probably unique in the universe.
  • Even though there are lots of stars in the universe, the odds are against any of them supporting complex life.
  • Here are just a few of the minimal requirements for habitability: must be a single star solar system, in order to support stable planetary orbits, the planet must be the right distance from the sun in order to have liquid water at the surface, the planet must sufficient mass in order to retain an atmosphere, etc.

The best non-theistic response to this argument is to postulate a multiverse, but that is very speculative and there is no experimental evidence that supports it.

Evidence #2: The origin of the universe

1. The progress of science has shown that the entire physical universe came into being out of nothing (= “the big bang”). It also shows that the cause of this creation event is non-physical and non-temporal. The cause is supernatural.

  • Atheism prefers an eternal universe, to get around the problem of a Creator having to create the universe.
  • Discovery #1: Observations of galaxies moving away from one another confirms that the universe expanded from a single point.
  • Discovery #2: Measurements of the cosmic background radiation confirms that the universe exploding into being.
  • Discovery #3: Predictions of elemental abundances prove that the universe is not eternal.
  • Discovery #4:The atheism-friendly steady-state model and oscillating model were both falsified by the evidence.
  • And there were other discoveries as well, mentioned in the lecture.

The best non-theistic response to this argument is to postulate a hyper-universe outside of ours, but that is very speculative and there is no experimental evidence that supports it.

Evidence #3: The origin of life

1. The progress of science has shown that the simplest living organism contains huge amounts of biological information, similar to the Java code I write all day at work. This is a problem for atheists, because the sequence of instructions in a living system has to come together all at once, it cannot have evolved by mutation and selection – because there was no replication in place prior to the formation of that first living system!

  • Living systems must support certain minimum life functions: processing energy, storing information, and replicating.
  • There needs to be a certain amount of complexity in the living system that can perform these minimum functions.
  • But on atheism, the living system needs to be simple enough to form by accident in a pre-biotic soup, and in a reasonable amount of time.
  • The minimal functionality in a living system is a achieved by DNA, RNA and enzymes. DNA and RNA are composed of sequences of proteins, which are in turn composed of sequences of amino acids.

Consider the problems of building a chain of 100 amino acids

  • The amino acids must be left-handed only, but left and right kinds are equally abundant in nature. How do you sort out the right-handed ones?
  • The amino acids must be bound together using peptide bonds. How do you prevent other types of bonds?
  • Each link of the amino acid chain needs to be carefully chosen such that the completed chain with fold up into a protein. How do you choose the correct amino acid for each link from the pool of 20 different kinds found in living systems?
  • In every case, a human or other intelligence could solve these problems by doing what intelligent agents do best: making choices.
  • But who is there to make the choices on atheism?

The best current non-theistic response to this is to speculate that aliens may have seeded the Earth with life at some point in the past.

The problem of the origin of life is not a problem of chemistry, it is a problem of engineering. Every part of car functionality can be understood and described using the laws of physics and chemistry. But an intelligence is still needed in order to assemble the components into a system that has the minimal requirements for a functioning vehicle.