The Greek word apologia (Greek: ἀπολογία) is the root for the English term “apologetics.” Apologia and its root forms are found in the New Testament (Acts 26:2; Romans 1:20; Philippians 1:7, 16), with 1 Peter 3:15 revealing the mandate imploring Christians to be ready to explain and defend their faith. Throughout Christian history, apologetics became known as the enterprise by which apologists sought to give a reasoned defense of the truth of Christianity. Today, Christian apologetics involves the use of various disciplines to defend the faith, including the biblical, doctrinal, philosophical, historical, literary, and scientific fields.

In more technical terms, apologetics is a branch of Christian theology that seeks to provide rational justification for the truth claims of Christianity.¹ For 20 centuries, Christian scholars and leaders have engaged in a fourfold defense of the faith by (1) presenting and clarifying the central truth claims of Christianity, (2) offering clear and compelling positive evidence for accepting Christian truth, (3) answering people’s questions and objections concerning the faith, and (4) providing a penetrating critique and refutation of alternative non-Christian systems of thought.²

This type of apologetic endeavor remains as important today as at any time in Christian history. And it is imperative that believers look to Scripture and church history to instruct them in the performance of this critical task. Fortunately, the apostle Peter—the central preacher in the primitive Christian church—offers such guidance in his first epistle.

Since 1 Peter 3:15 contains the official New Testament order or commission to do apologetics, let’s cite the passage and explore its meaning in some detail.

But in your hearts set apart Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect.

–1 Peter 3:15, NIV

Rules of Apologetic Engagement

In Peter’s words, we discover four points that provide a context for apologetic engagement and that honor God and instruct the apologist.

1. Courage in Suffering

The backdrop of Peter’s admonition in verse 15 is the topic of suffering (see verses 13–14 and 16–17). In the apostolic age as well as for virtually three centuries following, a defense of the Christian faith would often occur under hostile interrogation (see, for example, Acts 25:16). Since Christianity was an illegal and politically controversial religion in the Roman Empire, the early Christians suffered through periods of great persecution and even martyrdom. Apologetic work in the early church (as today in totalitarian and Islamic-ruled countries) took great moral and physical courage.

2. Christ’s Lordship

Peter instructs believers that at the core of their being (Greek: kardia, the “heart”), where people form their most essential beliefs, they should acknowledge the Lordship of Christ. Calling Jesus “Lord” (Greek: Kyrios) in this context is equivalent to referring to him as Yahweh(ruler, king, and God).³ Christians can engage in the apologetic enterprise with the full assurance that Christ is the exclusive, sovereign ruler over all things (Matthew 28:18). Facing suffering, trial, and hostile interrogation with the conviction that Christ is in sovereign control serves to grant the believer peace and confidence.

3. A Reasoned Defense

To provide the proper rational justification for the Christian faith and worldview today demands rigorous intellectual preparation. It presupposes an in-depth knowledge of the faith and the ability to answer questions and rebut objections. Peter sets forth the idea that the Christian faith has a rational foundation worth defending. Yet one does not need to be a professional to become an effective apologist.

4. Gentleness and Respect

When it comes to rational persuasion, the advocate’s attitude and demeanor often carry as much weight as his or her arguments. People measure the credibility of one’s beliefs often by how they are communicated. Cogent arguments conveyed with an air of arrogance and disrespect will be drained of their apologetic potency. But apologetic responses that reflect a calm, measured approach and tone signify a quality consistent with the conviction that it is God (the Holy Spirit) alone who makes the human heart and mind receptive to the gospel (Acts 16:14; 1 Corinthians 12:3).

The apostle goes on to speak of the importance of joining one’s rational defense with the virtue of moral transparency (“keeping a clear conscience,” verse 16). The effective apologist seeks to integrate the witness of one’s life with one’s words. A reasoned and winsome apologetic case possesses great force in conveying the message that historic Christianity is rational, viable, and true.

Reflections: Your Turn

Which aspect of Peter’s mandate concerning apologetics stands out to you? Visit Reflections on WordPress to comment with your response.

Extraterrestrial iron dust delivery by means of exquisitely fine-tuned processes has made modern civilization possible. Scientists sought to discern the nature of an unknown part of a phenomenon—bioavailable iron on Earth—and their research led to a major discovery that was published in the October issue of Geology.¹

Life has been present on Earth at a high abundance level throughout the past 3.8 billion years. While Earth’s continents possess the greatest diversity of life, it is the oceans that contain the greatest quantity of life—and the foundation for all this marine life is phytoplankton.

Phytoplankton Sustain Marine Life
Phytoplankton are microscopic organisms that engage in photosynthesis. They are primary producers in that they manufacture sugars, starches, and fats from water and carbon dioxide dissolved in water. These sugars, starches, and fats sustain the entire aquatic food web.

Phytoplankton account for more than half of all photosynthetic activity on Earth. When present at high-enough densities, some species are easily visible as colored patches on surface waters (see figure 1). Phytoplankton play a major role not only in sustaining marine life and diversity but also in removing sufficient quantities of carbon dioxide (a powerful greenhouse gas) from the atmosphere to compensate for the ever-brightening Sun (see figure 2).

Figure 1: Phytoplankton Blooms off the Southwest Coast of England
credit: NASA

Figure 2: The Sun’s Increasing Brightness throughout Life’s History. Image credit: Figure created by the author

What limits the quantity of phytoplankton in the oceans is the availability of iron—known as bioavailable iron—in physical and chemical forms that the phytoplankton can use.² In most of the surface waters of the world’s oceans, the concentration of bioavailable iron is very low, less than 0.2 nanomoles (roughly less than 2 parts per 10 billion).³

Sources of Bioavailable Iron
Scientists have long thought that the bioavailable iron present in the oceans has been delivered by eolian dust. Eolian dust, otherwise known as loess, refers to silt-sized material deposited by winds blowing off of exposed continental landmasses, primarily deserts and plateaus. This flux of bioavailable iron from eolian dust is geographically highly variable. Ocean regions far from deserts and plateaus receive very little of this dust. The Southern Ocean, which comprises most of Earth’s surface water, receives just 0.2–5 micromoles/square meter/year of bioavailable eolian dust.⁴ (This figure includes not just bioavailable iron but all bioavailable metals.)

The delivery of bioavailable eolian dust to the Southern Ocean falls considerably short of what is needed to sustain the quantity of phytoplankton known to exist there. Thus, geologists Peter Reiners of the University of Arizona and Alexandra Turchyn of the University of Cambridge present evidence in their paper that the delivery of bioavailable iron from extraterrestrial dust makes up the difference.

They begin by citing ice, marine sediment, and terrestrial sediment core records that establish a present-day flux of 40 million kilograms/year of iron delivery to Earth from interplanetary space.⁵ Reiners and Turchyn calculate how much of this iron is bioavailable. For the Southern Ocean, they conclude that the present flux of bioavailable iron from interplanetary space is comparable to and likely larger than the flux from eolian dust.⁶

Implications of Present-Day Interplanetary Iron Flux
Reiners and Turchyn do not comment in their paper on the implications of such abundant extraterrestrial bioavailable iron delivery to the present-day Southern Ocean. However, the implications seem obvious. The Southern Ocean would not be able to sustain the enormous biomass and biodiversity that it does without this ongoing delivery. Nor would the phytoplankton in the Southern Ocean be able to remove enough carbon dioxide from the atmosphere to compensate for the brightening of the Sun.

Without the present high rate of extraterrestrial bioavailable iron flux, advanced life and human civilization would not be possible. In fact, global high-technology civilization requires that this flux be fine-tuned.⁷

Past Sources of Extraterrestrial Bioavailable Iron
Reiners and Turchyn devote most of their research paper to addressing several events during the past half billion years when the flux of extraterrestrial dust was many times higher than it is at present. The most dramatic of these events is the Ordovician L-Chondrite Event that, according to meteorite geochronology and terrestrial stratigraphic records, occurred 470±6 million years ago and produced the Ordovician meteorite shower 467.3±1.6 million years ago.⁸ This shower lasted at least 2 million years and the extraterrestrial material flux was 100–1,000 times higher than the present rate.

The Ordovician L-Chondrite Event was likely caused by a major collision event in the Main Belt (the asteroid belt between Mars and Jupiter) that resulted in the breakup of a single large asteroid.⁹ This collision was responsible for most, if not all, L-chondrite meteorites. Even today it accounts for about 40 percent of all Earth-bound interplanetary objects.

The end-Ordovician mass extinction event ranks as the second most devastating mass extinction event known. Half of all animal genera and about 85 percent of all marine species were wiped out.¹⁰ While much of this extinction resulted from major impacts associated with the Ordovician L-Chondrite Event, the extremely high flux of interplanetary bioavailable iron dust would have so enhanced marine primary productivity from phytoplankton as to greatly draw down carbon dioxide from the atmosphere. The drawdown of so much of this important greenhouse gas explains the widespread glaciation event that was associated with the end-Ordovician mass extinction event. The greatly enhanced phytoplankton productivity also explains the enormous deposits of oolite ironstones (resulting from increased oxygen concentrations in the oceans) and black shales (resulting from enhanced burial of organic carbon) that were laid down at this time.¹¹

Similarly, Reiners and Turchyn show that three other major biological/depositional events, the late Miocene Veritas (8.3±0.5 million years ago¹²), end-Eocene (34.1–33.6 million years ago¹³), and Jurassic-Cretaceous (201–66 million years ago), were caused by much-enhanced fluxes of interplanetary bioavailable iron. The fluxes were 5, 6–10, and 4–10 times higher than the present flux, respectively.¹⁴ Each of these three events was accompanied by global cooling events and global depositions of oolite ironstones and black shales.

Implications of Past Interplanetary Iron Flux
As with present sources of interplanetary iron dust delivery to Earth, Reiners and Turchyn also decline to comment in their paper on the implications of past deliveries. Again, the implications seem obvious. Without the drawdowns of carbon dioxide that took place at each of the past four major iron dust deposition events, the increasing luminosity of the Sun would have heated Earth’s surface beyond the limit that life, especially advanced life, could withstand. Earth would have become a permanently sterile body long before the possible time window for human existence.

Without the much-enhanced productivity of marine phytoplankton, the treasure chest of biodeposits that presently exists would be much smaller. Lower reserves of biodeposits would have placed serious limitations on the capacity of humans to launch and sustain civilization. The maintenance of a human population in the billions—where those billions enjoy high-technology civilization—would not have been possible. Nor would it be possible for billions of humans to hear, understand, and respond in a brief window of time to Jesus Christ’s offer of redemption from sin. We indeed have many reasons to be grateful for bioavailable extraterrestrial iron dust being delivered to Earth in the just-right amounts at the just-right times.

The following question was posted on my Facebook page several days ago:

I understand that the fine-tuning evidence for God’s existence is overwhelming. But how do we know that this God is a personal Being? I know it myself from the indwelling of the Holy Spirit, but how do I explain it to a skeptic?

I answer this question at length in my book The Creator and the Cosmos.¹ Here, I will provide a much briefer answer.

The experimental and observational evidence that the universe has a beginning in finite time establishes that the universe must have some kind of Beginner. Space-time theorems provide additional evidence that some kind of causal Agent beyond space and time created our universe of matter, energy, space, and time. I describe and document in much detail the experimental, observational, and theoretical evidence for this causal Agent in The Creator and the Cosmos.²

While this evidence for a cosmic causal Agent establishes deism (the existence of an uncaused Agent that created the universe but does not interfere directly with the created universe), it does not necessarily establish theism (the existence of a Supreme Being who not only creates the universe but also directly intervenes in shaping the created universe to achieve specific purposes and goals). Deists reject either that God is a personal Being or that the personal Being who created the universe intervenes in any way at any point in the history of the universe beyond the cosmic creation event. Theists, on the other hand, assert that God is a personal Being and that he has demonstrated his personality by directly intervening throughout cosmic history to achieve his personal goals and purposes for the universe.

Christians frequently cite the fine-tuning of the universe, Milky Way Galaxy, solar system, Earth, and Earth’s life to make possible the existence of human beings and human civilization as indisputable evidence that God is a personal Being. I explain why this evidence is so powerful in chapters 5, 6, and 14­–17 of The Creator and the Cosmos.³

In many cases, the level of fine-tuning of the universe and the laws of physics to make possible the existence of human beings, or their functional equivalent, measures far beyond the best examples of fine-tuning achieved by us humans. Some examples would be the needed fine-tuning of dark energy, dark matter, the force of gravity, and the force of electromagnetism. That this fine-tuning far exceeds our best human achievements implies that the causal Agent—who designed these features for the existence and benefit of human beings—is, at minimum, many orders of magnitude more intelligent, knowledgeable, inventive, creative, and powerful than we humans. Since intellect, knowledge, inventiveness, creativity, and power are attributes that only a personal being can possess, the causal Agent who created the universe must be a personal Being.

Fine-tuning evidence for the existence and benefit of human beings, and high-technology human civilization in particular, is not limited to the laws of physics and the gross features of the universe. This evidence for fine-tuning is ubiquitous. It exists on all size scales.

As I show in The Creator and the Cosmos, for humans to possibly exist in the universe, not only must the laws of physics and the universe as a whole be exquisitely designed, but also the cluster of galaxies, the galaxy, the host star, the planetary system, the host planet, and the host planet’s moon in which the humans reside.⁴ Furthermore, as I show in my book Improbable Planet, the physical, chemical, and biological history of the humans’ planet must also be exquisitely fine-tuned.⁵ The required fine-tuning extends all the way down in size scales to molecules, atoms, and fundamental particles.

No matter where in the realm of nature human investigators look, they will find overwhelming scientific evidence for the existence of God and for the personal attributes of God. A quick look at the four past editions of The Creator and the Cosmos will affirm that the more we learn about nature, the more evidence we gain for the existence of an all-knowing, all-powerful, all-loving personal God and for what Paul declared in Romans 1:20 (Christian Standard Bible),

For his [God’s] invisible attributes, that is, his eternal power and divine nature, have been clearly seen since the creation of the world, being understood through what he has made.

By Hugh Henry

One of the greatest challenges to the theory of evolution is to explain sexuality. How could sexual reproduction have emerged by random, natural processes from early life-forms practicing asexual reproduction? How could natural selection evolve two versions of a species: essentially identical except for reproductive organs? When the data is analyzed, a creation perspective may make more sense.

Accounting for the Emergence of Sexual Reproduction

A review of the scientific literature reveals that the evolution of sexual reproduction has been described as “controversial,”¹ and as a “paradox”² and a “mystery.”³ A 2002 article in Nature Reviews Genetics states that “at least 20 theories had been proposed to explain the widespread occurrence of sexual reproduction”⁴; and a 2017 article in Trends in Ecology and Evolution observes that “many of the plausible hypotheses for sex have restrictive assumptions.”⁵ Moreover, there is no hard evidence for any of the twenty or so hypotheses.⁶

Yet the most perplexing question from an evolutionary perspective is: why did advanced life-forms evolve sexuality at all? Why didn’t we evolve based on asexual reproduction? To use a mythological image: why aren’t we all Amazon women?

It should be noted that asexual reproduction can be much more complex than simple cell division (mitosis). An advantage of sexual reproduction via meiosis is the exchange of genetic material; however, this can also be done asexually. For example, the phenomenon of parasexuality describes the direct transfer of genetic material among bacteria⁷; and, as first reported in 1953,⁸ it is common in fungi.⁹ Even some higher life-forms reproduce asexually via apomixis, which is reproduction by special generative tissues without fertilization; that is, without female and male union. The term apomixis includes parthenogenesis (in which a new individual develops from an unfertilized egg) in some plants, invertebrates, and even vertebrates.

The cell biology of some of these asexual reproductive mechanisms is similar to sexual reproduction in the transfer of genetic material; it’s just that distinct “male” and “female” forms are lacking. Since the theory of evolution often focuses on finding transitional forms, these asexual reproductive mechanisms might be viewed in that way.

However, the scientific literature suggests that these asexual processes could be a barrier to the development of sexuality, rather than a transition into it. Articles in the Journal of Heredity and Integrative Zoology, respectively, emphasize that sexual reproduction offers no advantage in the context of natural selection, and that it is less efficient than asexual reproduction:

Nobody has attributed any benefit of amphimixis [sexual reproduction] to the parents who are engaged in it, and the supposed beneficiaries are the offspring.10 [The] inherent costs [of sex] have made its maintenance difficult to explain. The most famous of these is the twofold cost of males, which can greatly reduce the fecundity [reproductive capacity] of a sexual population, compared to a population of asexual females.¹¹ A 2018 article article in Trends in Genetics summarizes the problems: The issue of the evolution of amphimixis involves three problems: (i) how it originated some 2 billion years ago; (ii) how it manages to outcompete obligate apomictic clones that keep emerging in some, although not all, amphimictic species; and (iii) how its gradual evolution does not turn amphimixis into apomixis or something similar. . . . Problem (iii) is the toughest one. Amphimixis can disappear not only abruptly, . . . but also gradually.¹²

These and other journal articles taken together reveal an interesting picture:

• There is no consensus among evolutionary biologists about the development of sexual reproduction, and many of the hypotheses are structured as restrictive “just so stories” requiring a cascade of unlikely events.
• Most—if not all—life-forms could be configured for asexual reproduction.
• Sexual reproduction is more “expensive” than asexual reproduction; it is more difficult and requires more energy.
• From the point of view of natural selection, there is no benefit to sexual reproduction. To the contrary, asexual reproduction offers reproductive advantage over sexual reproduction.
• The real question may be how do we keep sexual reproduction—however we acquired it. Why do we and other sexual life-forms not devolve into the less “expensive” condition of asexuality?

Which Model Makes More Sense?

In light of all the above, the evolution of sexual reproduction by random, spontaneous processes makes no sense. Assuming natural selection as the mechanism, evolution should have stopped with some form of asexual apomixis. Even if a life-form had happened to evolve sexual reproduction, it would have disappeared because there was no reproductive advantage.

There must be a different answer . . . and that answer may be found in the Bible: God created man in His own image, in the image of God He created him; male and female He created them (Genesis 1:27 NASB). The LORD God said, “It is not good for the man to be alone; I will make him a helper suitable for him” (Genesis 2:18 NASB).

Sexual reproduction is not for efficiency; it offers no reproductive advantage. Why does it exist? It may be for companionship and partnership, as ordained by the creator-God for humans—and for many animals as well. It seems most plausible that it came from a loving God—not as the product of an evolutionary processes.

Acknowlegment:

This topic was the idea of my 17-year-old grandson, Jeff Obermeyer, Jr., who deserves special credit for his insight.

To find out more about Hugh Henry, please check out his biography.

The Christian church has been graced with brilliant and influential thinkers since its inception. A list of “who’s who” in Christian scholarship would be long and diverse in terms of scholarly disciplines. To whet your appetite in the areas of theology and philosophy, here’s a snapshot of six “straight A” thinkers.

By “straight A,” I mean two things. First, I’m noting that these thinkers were all brilliant scholars (no doubt, they would’ve received straight A report cards in today’s grading system) and accomplished philosophers and theologians who advanced Western civilization in general, and Christianity in particular. Second, all of these distinguished Christian scholars’ names begin with the letter “A.” So they’re Christendom’s A-Team!

Christendom’s A-Team

Here’s a brief summary of the “straight A” Christian theologians and philosophers from ancient and medieval Christendom and what they are known for:

1. Athanasius (ca. 296–373), Defender of Orthodoxy

Athanasius is one of the most honored theologians in church history. His articulation and defense of essential Christian doctrine earned him the title “Father of Orthodoxy.” With his rare combination of a tenacious character and depth of theological insight, Athanasius championed the doctrine of the incarnation at a time when the faith was extremely vulnerable to heretical attack.

2. Ambrose (ca. 340–397), The Great Orator

Ambrose is recognized as a Doctor of the Catholic Church and is known as one of the great orators in Christian history. A classically educated scholar, he helped introduce Greek Christian thinkers to the Latin West. Ambrose served as a skilled church theologian and bishop. Ambrose was deeply influential in the conversion of St. Augustine and later baptized him into the faith.

3. Augustine (354–430), Greatest Author of Antiquity

Augustine of Hippo is arguably the most influential Christian thinker outside the New Testament authors. History knows him as a theologian, philosopher, church bishop, and a gifted and tenacious defender of orthodox Christianity. Having penned more than five million words, Augustine was the most prolific author of antiquity. He wrote several books that are considered both Christian and literary classics, including Confessions and The City of God.

4. Anselm (1033–1109), Integrator of Faith and Reason

Anselm of Canterbury is honored as a Doctor of the Catholic Church and has been recognized as the greatest Christian thinker between St. Augustine and St. Thomas Aquinas. He is well-known for his understanding of the relationship between faith and reason and for formulating one of the most distinctive arguments ever—the ontological argument—for the existence of God.

5. Abelard (1079–1142), The Medieval Logician

Peter Abelard is considered one of the great scholars of the Christian Middle Ages. As a French scholastic philosopher, he contributed significantly to such fields as logic and the problem of universals. As a theologian, his extravagant life and controversial beliefs were sometimes criticized by the church, but he still made contributions in Christian doctrine and practice.

6. Aquinas (1225–1274), The Catholic Philosopher

Thomas Aquinas may have possessed the brightest mind in the history of Christendom. A medieval scholastic philosopher and theologian, Aquinas’s system of thought (called “Thomism”) was declared the official philosophy of the Roman Catholic Church. In a lifespan of fewer than 50 years, he wrote voluminously and masterfully defended classical Christian theism.

In the modern world, people sometimes ask whether the Christian faith is compatible with reason. But for most of Western civilization, the greatest intellectuals were also people of deep Christian faith. Today’s Christians could greatly benefit from knowing about these scholars of Christendom’s ancient and medieval past.

My faith is uplifted by knowing that these people affirmed the same historic Christian truths that I do.

Reflections: Your Turn

Who is your favorite Christian thinker of the past outside of the Bible? What lessons can today’s believers learn from earlier Christians? Visit Reflections on WordPress to comment with your response.

Resources

For more in-depth articles that highlight these men’s lives, writings, and contributions to Christendom, see:

• “Christian Thinkers 101: A Crash Course on St. Athanasius” by Kenneth Samples (article)
• “Christian Thinkers 101: A Crash Course on St. Augustine” by Kenneth Samples (article)
• “Christian Thinkers 101: A Crash Course on St. Anselm” by Kenneth Samples (article)
• “Think Again: Christianity’s Relationship to Reason” by Kenneth Samples (article)
• “Christian Thinkers 101: A Crash Course on St. Thomas Aquinas” by Kenneth Samples (article)

Were there no example in the world of contrivance except that of the eye, it would be alone sufficient to support the conclusion which we draw from it, as to the necessity of an intelligent Creator.

–William Paley, Natural Theology

In his classic work, Natural Theology, William Paley surveyed a range of biological systems, highlighting their similarities to human-made designs. Paley noticed that human designs typically consist of various components that interact in a precise way to accomplish a purpose. According to Paley, human designs are contrivances—things produced with skill and cleverness—and they come about via the work of human agents. They come about by the work of intelligent designers. And because biological systems are contrivances, they, too, must come about via the work of a Creator.

For Paley, the pervasiveness of biological contrivances made the case for a Creator compelling. But he was especially struck by the vertebrate eye. For Paley, if the only example of a biological contrivance available to us was the eye, its sophisticated design and elegant complexity alone justify the “necessity of an intelligent creator” to explain its origin.

As a biochemist, I am impressed with the elegant designs of biochemical systems. The sophistication and ingenuity of these designs convinced me as a graduate student that life must stem from the work of a Mind. In my book The Cell’s Design, I follow in Paley’s footsteps by highlighting the eerie similarity between human designs and biochemical systems—a similarity I describe as an intelligent design pattern. Because biochemical systems conform to the intelligent design pattern, they must be the work of a Creator.

As with Paley, I view the pervasiveness of the intelligent design pattern in biochemical systems as critical to making the case for a Creator. Yet, in particular, I am struck by the design of a single biochemical system: namely, the genetic code. On the basis of the structure of the genetic code alone, I think one is justified to conclude that life stems from the work of a Divine Mind. The latest work by a team of German biochemists on the genetic code’s design convinces me all the more that the genetic code is the product of a Creator’s handiwork.¹

To understand the significance of this study and the code’s elegant design, a short primer on molecular biology is in order. (For those who have a background in biology, just skip ahead to The Optimal Genetic Code.)

Proteins

The “workhorse” molecules of life, proteins take part in essentially every cellular and extracellular structure and activity. Proteins are chain-like molecules folded into precise three-dimensional structures. Often, the protein’s three-dimensional architecture determines the way it interacts with other proteins to form a functional complex.

Proteins form when the cellular machinery links together (in a head-to-tail fashion) smaller subunit molecules called amino acids. To a first approximation, the cell employs 20 different amino acids to make proteins. The amino acids that make up proteins possess a variety of chemical and physical properties.

Figure 1: The Amino Acids. Image credit: Shutterstock

Each specific amino acid sequence imparts the protein with a unique chemical and physical profile along the length of its chain. The chemical and physical profile determines how the protein folds and, therefore, its function. Because structure determines the function of a protein, the amino acid sequence is key to dictating the type of work a protein performs for the cell.

DNA

The cell’s machinery uses the information harbored in the DNA molecule to make proteins. Like these biomolecules, DNA consists of chain-like structures known as polynucleotides. Two polynucleotide chains align in an antiparallel fashion to form a DNA molecule. (The two strands are arranged parallel to one another with the starting point of one strand located next to the ending point of the other strand, and vice versa.) The paired polynucleotide chains twist around each other to form the well-known DNA double helix. The cell’s machinery forms polynucleotide chains by linking together four different subunit molecules called nucleotides. The four nucleotides used to build DNA chains are adenosine, guanosine, cytidine, and thymidine, familiarly known as A, G, C, and T, respectively.

Figure 2: The Structure of DNA. Image credit: Shutterstock

As noted, DNA stores the information necessary to make all the proteins used by the cell. The sequence of nucleotides in the DNA strands specifies the sequence of amino acids in protein chains. Scientists refer to the amino-acid-coding nucleotide sequence that is used to construct proteins along the DNA strand as a gene.

The Genetic Code

A one-to-one relationship cannot exist between the 4 different nucleotides of DNA and the 20 different amino acids used to assemble polypeptides. The cell addresses this mismatch by using a code comprised of groupings of three nucleotides to specify the 20 different amino acids.

The cell uses a set of rules to relate these nucleotide triplet sequences to the 20 amino acids making up proteins. Molecular biologists refer to this set of rules as the genetic code. The nucleotide triplets, or “codons” as they are called, represent the fundamental communication units of the genetic code, which is essentially universal among all living organisms.

Sixty-four codons make up the genetic code. Because the code only needs to encode 20 amino acids, some of the codons are redundant. That is, different codons code for the same amino acid. In fact, up to six different codons specify some amino acids. Others are specified by only one codon.

Interestingly, some codons, called stop codons or nonsense codons, code no amino acids. (For example, the codon UGA is a stop codon.) These codons always occur at the end of the gene, informing the cell where the protein chain ends.

Some coding triplets, called start codons, play a dual role in the genetic code. These codons not only encode amino acids, but also “tell” the cell where a protein chain begins. For example, the codon GUG encodes the amino acid valine and also specifies the starting point of the proteins.

Figure 3: The Genetic Code. Image credit: Shutterstock

The Optimal Genetic Code

Based on visual inspection of the genetic code, biochemists had long suspected that the coding assignments weren’t haphazard—a frozen accident. Instead it looked to them like a rationale undergirds the genetic code’s architecture. This intuition was confirmed in the early 1990s. As I describe in The Cell’s Design, at that time, scientists from the University of Bath (UK) and from Princeton University quantified the error-minimization capacity of the genetic code. Their initial work indicated that the naturally occurring genetic code withstands the potentially harmful effects of substitution mutations better than all but 0.02 percent (1 out of 5,000) of randomly generated genetic codes with codon assignments different from the universal genetic code.²

Subsequent analysis performed later that decade incorporated additional factors. For example, some types of substitution mutations (called transitions) occur more frequently in nature than others (called transversions). As a case in point, an A-to-G substitution occurs more frequently than does either an A-to-C or an A-to-T mutation. When researchers included this factor into their analysis, they discovered that the naturally occurring genetic code performed better than one million randomly generated genetic codes. In a separate study, they also found that the genetic code in nature resides near the global optimum for all possible genetic codes with respect to its error-minimization capacity.³

It could be argued that the genetic code’s error-minimization properties are more dramatic than these results indicate. When researchers calculated the error-minimization capacity of one million randomly generated genetic codes, they discovered that the error-minimization values formed a distribution where the naturally occurring genetic code’s capacity occurred outside the distribution. Researchers estimate the existence of 10¹⁸ (a quintillion) possible genetic codes possessing the same type and degree of redundancy as the universal genetic code. Nearly all of these codes fall within the error-minimization distribution. This finding means that of 10¹⁸ possible genetic codes, only a few have an error-minimization capacity that approaches the code found universally in nature.

Frameshift Mutations

Recently, researchers from Germany wondered if this same type of optimization applies to frameshift mutations. Biochemists have discovered that these mutations are much more devastating than substitution mutations. Frameshift mutations result when nucleotides are inserted into or deleted from the DNA sequence of the gene. If the number of inserted/deleted nucleotides is not divisible by three, the added or deleted nucleotides cause a shift in the gene’s reading frame—altering the codon groupings. Frameshift mutations change all the original codons to new codons at the site of the insertion/deletion and onward to the end of the gene.

Figure 4: Types of Mutations. Image credit: Shutterstock

The Genetic Code Is Optimized to Withstand Frameshift Mutations

Like the researchers from the University of Bath, the German team generated 1 million random genetic codes with the same type and degree of redundancy as the genetic code found in nature. They discovered that the code found in nature is better optimized to withstand errors that result from frameshift mutations (involving either the insertion or deletion of 1 or 2 nucleotides) than most of the random genetic codes they tested.

The Genetic Code Is Optimized to Harbor Multiple Overlapping Codes

The optimization doesn’t end there. In addition to the genetic code, genes harbor other overlapping codes that independently direct the binding of histone proteins and transcription factors to DNA and dictate processes like messenger RNA folding and splicing. In 2007, researchers from Israel discovered that the genetic code is also optimized to harbor overlapping codes.⁴

The Genetic Code and the Case for a Creator

In The Cell’s Design, I point out that common experience teaches us that codes come from minds. By analogy, the mere existence of the genetic code suggests that biochemical systems come from a Mind. This conclusion gains considerable support based on the exquisite optimization of the genetic code to withstand errors that arise from both substitution and frameshift mutations, along with its optimal capacity to harbor multiple overlapping codes.

The triple optimization of the genetic code arises from its redundancy and the specific codon assignments. Over 10¹⁸ possible genetic codes exist and any one of them could have been “selected” for the code in nature. Yet, the “chosen” code displays extreme optimization—a hallmark feature of designed systems. As the evidence continues to mount, it becomes more and more evident that the genetic code displays an eerie perfection.⁵

An elegant contrivance such as the genetic code—which resides at the heart of biochemical systems and defines the information content in the cell—is truly one in a million when it comes to reasons to believe.

Resources

• The Cell’s Design: How Chemistry Reveals the Creator’s Artistry by Fazale Rana (book)
• “FYI: I. D. IN DNA Deciphering Design in the Genetic Code” by Fazale Rana (article)
• “The Genetic Code: Simply the Best” by Fazale Rana (article)
• “Mitochondria’s Deviant Genetic Code: Evolution or Creation?” by Fazale Rana (article)
• “Biochemical Synonyms Optimized, Part 1 of 2” by Fazale Rana (article)
• “Biochemical Synonyms Optimized, Part 2 of 2” by Fazale Rana (article)
• “Protein Amino Acids Form a ‘Just Right’ Set of Biological Building Blocks” by Fazale Rana (article)
• “Why These 20 Amino Acids?” by Fazale Rana (article)
• “The Optimal Design of Metabolism” by Fazale Rana (article)
• “Metabolism: A Cascade of Design” by Fazale Rana (article)

Many people who witnessed the great eclipse of 2017 will remember it as a wondrous spectacle. But one amateur astronomer saw the event as an opportunity to reproduce measurements of the celebrated general theory of relativity, which provides the basis for understanding cosmological models of our expanding universe.

In 1915, Albert Einstein first presented his new model for describing gravity to the Prussian Academy of Sciences. Motivated by the notion that the laws of physics should not depend on location in or motion through the universe, Einstein had developed what we now call the general theory of relativity (GR). When first published, GR did not make much of a splash. Even after three or four years, Einstein lived in relative obscurity until a key measurement in 1919 brought him scientific fame.

A solar eclipse that traversed the Atlantic Ocean from South America to Africa propelled Einstein’s theory to prominence. According to GR, the gravitational well of the Sun should deflect light from distant stars by a predictable amount—an amount twice as large as predicted by Newtonian gravity. Like any solar eclipse, weather can unravel the best-laid plans. So astronomer Sir Arthur Eddington planned for two groups to make the critical measurements. Eddington and astronomer Sir Frank Watson Dyson traveled to Sobral, Brazil, while sending fellow astronomers Andrew Claude de la Cherois Crommelin and Charles Davidson to Príncipe Island off the west coast of Africa. Both groups found clear enough skies to observe stars during the eclipse. Eddington used the observations from Príncipe Island to compare star locations during the eclipse and six months earlier (when the same stars are in the sky at night). Eddington published a paper in 1920 declaring that “results of the observations here described appear to point quite definitely to . . . and confirm Einstein’s generalised relativity theory.”¹

This first test of GR brought international recognition to Einstein and started a long chain of experiments that establish GR as arguably the most accurate description of the universe known. However, some people have questioned whether Eddington’s result actually supported GR or whether he may have shown some bias.² History shows that GR is correct and that subsequent reanalysis of Eddington’s data validates his conclusions. Yet, scientists continually seek to improve upon results.

Donald Bruns, an amateur astronomer from San Diego, used a $4,000 telescope and a $5,000 camera to execute a plan he had perfected over two years. He took his setup to Casper, Wyoming, to photograph the 2017 eclipse and measure the deflection of stars as originally done by Eddington. Analyzing the data from his observations, he measured a deflection coefficient of 1.7512 arcsec.³ This value agrees with the predictions of GR within 3%, a marked improvement over previous optical attempts that had only achieved 10% accuracy. According to Physics Today, Brun’s work is “the most accurate and precise ground-based optical version of the Eddington experiment.”

Although Bruns’s research doesn’t fall into the class of “breakthrough,” it does represent scientists’ ongoing pursuit to understand the intimate and minute detailed workings of the cosmos. It also shows that relatively inexpensive projects can contribute significant results. But most importantly, it highlights the incredible curiosity and creativeness that drives humans—bearers of God’s image—to know the truth!