This Essay is the third of six (#10 through #15) interrelated Essays on Earth’s geochemical origin of life and its subsequent Evolution. Here are the titles of those six Essays:

Essay #10 — The Processes of Evolution — In Biology, Culture, & Technology
Essay #11 — Answering Evolution’s Critics
Essay #12 — Chemical Precursors to Life on Earth (this Essay)
Essay #13 — The Organic Molecules & Processes that Form Life
Essay #14 — Abiogenesis: Evolution of the First Life on Earth
Essay #15 — Where Life Began: Warm Pools? Black Smokers?

Essay #10, The Processes of Evolution & Their Meaning, is just as important as the “biological five” Essays listed above because that earlier Essay describes the evolution happening all around us, here and now, in three arenas: biology, culture, & technology.  It takes all six Essays to fully explain how the processes of evolution provide us with our complete human appreciation for Connectedness & Meaning based on Nature, Science, & History.

While we understand that a Deist “clockmaker-God” may have started the universe, we can’t prove it up or down.  However, the universe exists, and evolutionary processes are at work on Earth. As these processes evolve, they generally become more complex, likely following a similar pattern on other planets in other solar systems when planetary conditions are suitable.  (For more on Deism, see our Essay, Forerunners to Our Path & Practice.)

To recap past Essays, the fundamental creative process in Nature’s Continuing Creation is this: When a steady flow of energy encounters a receptive environment, it weaves patterns and creates systems of increasing Complexity.

Most biologists agree that all Earthly organisms living today (and in the past) evolved from a single primitive one-celled lifeform. ³ The consensus holds that this “First Life” emerged by natural geochemical processes about 3,900 million (3.9 billion) years ago. Yet, many questions remain unanswered.

Non-living systems often have some of the characteristics of living organisms. Sometimes, it is challenging to distinguish pre-living systems from living organisms. This Essay tries to deal only with pre-living systems, but sometimes we will need to mention certain living organisms for the sake of clarity. 

This Essay you are now reading explains how the first living thing on Earth could have emerged naturally from the processes of chemistry, coupled with the favorable conditions available to it here on this planet. Our point of view aligns with philosophical Naturalism, which holds that only natural causes are taken seriously.

Before life began, there must have been a process of chemical change, a process of chemical evolution, happening before the process of biological evolution. ⁴ This is consistent with Nature’s Path of Continuing Creation’s definition of evolution as a set of linked processes that started with the Big Bang and cosmic evolution, continued with geochemical evolution, then biological evolution, and includes the human-agented evolution of culture and technology.

Why We Oppose Fundamentalist, Biblical “Creationism”

When biblical creationists criticize biological evolution, they like to point out that placing all the parts of a watch in a vat of water and stirring them up does not make an assembled, working watch. They cite a paper by Fred Hoyle and Chandra Wickramasinghe, which calculates that the probability of all the chemicals in a simple bacterium arising on their own by chance is 1 in 10 to the 40,000^th power. They say that the odds of creating a protein molecule by chance are only 1 in 10 to the 45th power. ⁵

But their argument is an oversimplification. It overlooks the fact that sophisticated life forms, such as current-day bacteria or even a complex protein molecule, almost certainly did not arise spontaneously from a random mix of chemicals. They arose from simpler, incremental steps that had a much higher chance of occurring. Protein molecules, for example, are made out of simpler amino acid molecules. ⁶

Biblical creationists also overlook the fact that there are approximately 4 × 10^47 molecules of water in Earth’s oceans. So, even if there were only one amino-acid molecule among 1 million water molecules, that would still be 10⁴¹ amino-acid molecules that had the opportunity to interact with each other, in numerous environments, in numerous places, and in numerous trials over millions of years, to eventually produce basic proteins. ⁷

The relevant probability is not the chance of hundreds of complex chemicals coming together to form a modern-day bacterium, but the probability of 10 or 20 chemicals coming together to form the precursors of life, precursors that can then chemically evolve over time to form the simplest kind of life form, one that likely looked nothing like any evolved life form we recognize today. ⁸

Biblical creationists also charge that we, Participants in Nature’s Continuing Creation, have “faith” in science, that we have made a religion out of science, and that we want to make “science” into a God.  No, we are not doing those things.  We don’t have faith, we have confidence in the scientific method and optimism about its ability to find answers and solve problems.  We do not completely reject the very remote possibility of God-the-Creator, but we hold that Continuing Creation is more accurately described by scientific knowledge about the Natural Processes of Nature’s Growing, Organizing, Direction of the Cosmos than it is by the anthropomorphic verses in the Bible, the Koran, or in the Bhagavad Gita. 

People who are determined to keep their traditional faith in a supernatural God should ask themselves this: Which is more powerful, more creative: a God who decrees human life into existence, or the Sum of all the Interacting Processes of Natural Continuing Creation? Processes that include the rules of physics and chemistry, such that intelligent life will emerge from them on some of the six billion Earth-like planets all across the Milky Way Galaxy? ⁹

Still, respected scientists such as Stephen Meyer and James Tour argue that even a single living cell exhibits such an astounding, incredibly complex organization that it cannot be explained by laboratory assemblies of energized chemicals. They think that a cell’s complexity and coordinated complexity can only be explained by “intelligent design.” To quote one of them, “A code requires a Coder.” However, the two Doctors have no idea where the intelligent design originated. From an equally complex universe?  From an overarching mind?  No one knows, and we humans may never know.  Both these men think, however, that Darwinian Evolution is the correct explanation for how fish, plants, and intelligent human life evolved from a single-celled “First Organism.” (See Peter Robinson’s filmed interview of Drs. Meyer and Tour, “Beyond Evolution: Unraveling the Origins of Life,” published online (YouTube) by the conservative Hoover Institution located on the campus of Stanford University.)  See also our own Essays #13, #14 & #15, listed in our Table of Contents.  

The Driver for All Evolution is Increasing Energy Efficiency

Darwin’s “Natural Selection” is not the most fundamental driving force behind evolution. So, what is?  Professors Adrian Bejan and Jeremy England argue that the most fundamental driving force in evolution is the tendency toward increasing energy-flow efficiency that happens in all open thermodynamic systems, both in living and nonliving systems, and that this force has the same effect in both chemical evolution and biological evolution. Our own book — Nature’s Path of Continuing Creation — agrees with them.

In his well-reviewed book of 2013, The Romance of Reality, Dr. Bobby Azarian tells us that wherever energy flows (e.g., from hot to cold), the flow can drive natural systems to self-organize into structures that can move more energy through faster. For example, when water runs out of a bathtub, it adopts an organized structure similar to a whirlpool to empty the tub more quickly. Many inorganic chemical systems exhibit this behavior, and so do the structures of living organisms. This fact has led a majority of NASA astrophysicists to conclude that the emergence of life may be widespread across the millions of Earth-like planets and moons in our own galaxy, the Milky Way. ¹⁰

Professor Adrian Bejan’s “Constructal Law”

In their book Design in Nature, Adrian Bejan and his co-writer, J. Peder Zane, argue that the Earth’s process of evolution creates and then utilizes microorganisms because they enhance the constructive efficiency of energy flow. 

Note:  Dr. Adrian Bejan is Professor of Mechanical Engineering at Duke University, and the author, with J. Peder Zane, of Design in Nature: How the Constructal Law Governs Evolution in Biology, Physics, Technology, and Social Organization (2013) and many other books. Dr. Bejan has received 16 honorary doctorates from universities in 11 countries. ¹¹

There is evolution in both geology and chemistry. In geology, the flow of water across the land has evolved to develop small tributaries that gather water into rivers, as this is the most energy-efficient way to collect and transport water from high mountains to the low shore. A river delta is much like the branching bronchial tubes in our lungs. They are each the most efficient ways to exhale carbon dioxide and disperse river water, respectively.

The driving force for both chemical and biological evolution is the drive for constructive energy efficiency. The selection mechanism for both chemical and biological evolution is the environment. The “environment” can be geologic (“the valley is hemmed in by mountains”), chemical (“can’t handle sulfur in the atmosphere”), biological (“one pack of wolves is stronger than the others”), or it can be a mix of these.  In all cases, it is the environment that naturally selects which organisms will survive (and have a chance to improve over generations), and which will not.

Many animals, including humans, were naturally selected for swimming ability by the existence and the nature of Earth’s oceans. and later for walking & running on Earth’s surface. Similarly, birds, bats, and certain species of dinosaurs were naturally selected for flight due to the existence and nature of Earth’s atmosphere. Why?  Because these modes of travel – swimming, running, & flying – provide the most energy-efficient ways for Earthly animals to find and eat foods that are present in those three environments.

Dr. England’s Theory of Increasing Energy Efficiency

In 2014, Dr. Jeremy England, a physics professor at MIT, followed the 2013 publication of the book by Bejan and Zane by arguing that the driving force for chemical evolution may be hidden in physics… “From a physics point of view, the one thing that distinguishes living things from non-living things is their ability to capture energy and convert it into a fuel which is then burned or undergoes some other chemical reaction to make heat.” ¹²

Note: Dr. Jeremy England holds a PhD in Physics from Stanford. He was an Assistant Professor of Physics at MIT until joining the biological products firm Glaxo-Smith-Kline in 2019 as Senior Director of Artificial Intelligence and Machine Learning.

The Systems Dr. England talks about are best described as “energy flow-through systems.” ¹³ An energy flow-through system is a thermodynamically open system that builds a dynamic structure. ¹⁴ The structure does this by exchanging energy and matter with its environment. A tornado may be thought of as an inorganic energy flow-through system:  it takes in wind from two or more sides, makes a funnel structure by circling the wind around and around, moving the air faster and faster, and focusing it on a small area of land or sea. Energy flow-through systems contrast with energy-conserving systems. ¹⁵

Trees are organic, biological flow-through systems that raise water to the sky more efficiently than normal evaporation into the atmosphere does, thereby speeding up Earth’s water cycle.

A human being is another example of an organic, living, energy flow-through structure. A human being starts as a fertilized human egg (zygote) that exchanges energy and matter with its environment.  As it does so, it increases the size, complexity, and power of its structure (a human body, a human life), until it ultimately disintegrates (dies) and its heat and organization disperse.

             “From dust to dust.” (Ecclesiastes 3:20; also, in The Funeral Service in the Book of Common Prayer.) ¹⁶

In the realm of chemistry, England argues that when exposed to an external source of energy, such as the sun or geothermal heat from below Earth’s surface, any group of molecules will restructure themselves to flow through more energy more efficiently. This, he says, is the driving force for chemical evolution. Over time, this force can result in living organisms, such as those we see today – organisms that are highly efficient at harnessing energy for constructive purposes.  ¹⁷.

When oxygen became prevalent in Earth’s seas and atmosphere, many species shifted their respiration chemistry from anaerobic to aerobic processes because the latter is far more efficient at producing energy (ATM molecules) for construction, repair, motion, and communication within the cell. The presence of atmospheric oxygen permitted the evolutionary rise of oxygen-breathing animals. They arose via the processes of evolution because Aerobic respiration (i.e., oxidation) produces more energy (or produces the same amount of energy more efficiently) than anaerobic respiration.

We can say that efficient gathering, transporting, and distributing energy for constructive purposes is pretty much a restatement of our own definition of Life, which is: “Order, organization, pattern, or structure arising from natural processes (including human-agented ones) and powered by an energy flow – such as sunlight, volcanic heat, motion, and electro-chemical radiation.” 

A living organism’s metabolism is all about energy flow. ¹⁸ There is an inherent tension in metabolism between two things: homeostasis and evolution. Energy flows through but does not destroy the organism, at least for the span of its lifetime. Eventually, Mother Nature cashes in her chips on every living thing, and then she places bets on newly evolved plants and creatures.

Chemistry’s Definition of Life

 “Chemistry provides a firm foundation for defining life, for all living things are organized molecular systems that undergo
chemical reactions of astonishing intricacy and coordination.”
                 — Dr. Robert M. Hazen, Mineralogist and Astrobiologist; Author of The Story of Earth. ¹⁹ 

 A panel at the Scripps Research Institute, chaired by Dr. Gerald Joyce, came up with an excellent one-sentence definition of Life:  “Life is a self-sustaining chemical system capable of incorporating novelty and undergoing Darwinian evolution.” ²⁰

The very first life on Earth must have started from non-living matter – because, by definition, “First-life” could only be preceded by “non-life.” ²¹ The earliest protocells (“pre-cells”) may not have met all the definitional requirements for life. They may have lacked one or more of the Key Processes of Life that we talk about in other Essays.  However, the chemical systems that evolved earlier than First Life foretold features of the organisms that would evolve later.

Geochemical Evolution — Before Life Evolved

Some argue that biological evolution is not the same as chemical evolution because only biological evolution is driven by “natural selection,” a process that favors those organisms with the best chance of survival and reproduction.  However, the chemical compounds that appear on Earth, and their states of matter (solid, liquid, or gaseous), clearly evolved from Earth’s planetary environment.  They were selected by our planet’s distance from the sun, its volcanic activity, gravity, temperature, pressure, and mineral composition.

Earth evolved both its atmosphere and its oceans.  As a result of gravity and geochemistry, Earth’s atmosphere is made up of 78% nitrogen and 21% oxygen, not 96% carbon dioxide, like Venus and Mars, or nearly all hydrogen and helium like Jupiter.  Earth’s modern atmosphere evolved to contain 20% oxygen as the result of trillions of cyanobacteria discharging their photosynthetic “waste oxygen” into the air during prehistoric eons.  (We will further discuss this transformation in a sequel Essay.)    

We tend to think of living creatures, even the most primitive of microbes, as the “heroes” of the early biological evolution story. However, bacteria and archaea organisms lack brains, make no decisions, and have no consciousness with which to “struggle.”  Instead, we should view the processes of evolutionary creation as the hero, the protagonist of the story, even though they also have no central brain.  This is true not only for biological evolution, but also for geological and chemical evolution.

A Review of Emergence

We use the word “emergence” many times in our Essays on the Evolution of life. In fact, our primary objective is to demonstrate that First-Life likely originated from geochemistry. “Emergence” is an important concept in modern science, and we discuss it at length in our Essay, “Nature Creates Increasingly Complex Systems.” Readers may want to pause to read or review it.

“Emergence occurs when an entity is observed to have properties that its parts do not have on their own; properties or behaviors which emerge only when the parts interact in a wider whole.”  — Wikipedia on Emergence

Emergence is the creation of a whole that is qualitatively quite different than the sum of its parts. A bicycle emerges from the union of its parts – wheels, frame, handles, seat, pedals, and so on.  None of those parts, by themselves, can enable a rider to ride down a road. The human body is composed of cells, but none of those individual cells can pump blood or see a tree.  Water is composed of oxygen and hydrogen, but neither of those gases, by themselves, has the characteristics of water. Water’s very liquidity emerges only when O and H2 combine (at one atmosphere of pressure and 33 to 211 degrees F).

While there is no single generally accepted theory of the origin of life, all credible proposals show that life, under natural conditions, by a slow process of chemical and molecular evolution, could have plausibly resulted in simple forms of life over a long period of time; and that this chemical evolution was probably the biggest hill to climb for life to have occurred on Earth.  (See Arvin Ash’s video-film presentation, “Abiogenesis – How Life Came from Inanimate Matter,” which is viewable for free at arvinash.com.) 

Once Abiogenesis happened, biological evolution took over and relatively quickly resulted in an exceptional diversity of life forms. We observe this diversity in the fossil record of early Earth, as well as on Earth today.  Do we have proof that this is how life came about?  No… at least not yet. Is it plausible?  Absolutely! ²²

So, First Life (and the science of biology) very likely comes from geochemistry.

Abiogenesis – a First Glimpse

  “Abiogenesis: When Chemistry Turned into Biology” — Dr. Lawrence Krauss                         

Abiogenesis (informally, the origin of life) is the natural process by which life has arisen from non-living matter, particularly from chemical precursors.  Specifically, life arose from chemical compounds that contain carbon that is bonded to hydrogen. Since these chemicals continue to be incorporated within living organisms, they are referred to as organic compounds. ²³

Chemical evolution preceded biological evolution. The transition between the two is called “abiogenesis.” Note that abiogenesis is technically not part of biological evolution because, by definition, abiogenesis took place before all biological evolution. However, if we contend that grand evolution encompasses geology, chemistry, biology, culture, and technology, as we do here in this book on Nature’s Continuing Creation, then Abiogenesis is part of the grand evolution that encompasses chemical evolution, the origin of life, the evolution of Humans, and the technology that humans create. ²⁴

We Discuss Abiogenesis in Essay #14: Abiogenesis: Evolution of First Life on Earth

Note: There is no “standard model” for Abiogenesis. Instead, there are several theoretical models, each one supported by evidence from geology, chemistry, molecular biology, and cell biology. We will discuss each of these models later in Essay #14, Abiogenesis: Evolution of the First Life on Earth. The expression “Scientific Model” has largely replaced the older “Scientific Hypothesis.” The word “model” is thought to better convey the fact that all chains of scientific reasoning must remain open to the discovery of new facts and/or verification by new experimental results. For a larger discussion, see “Hypothesis, Model, Theory, and Law,” ThoughtCo, at https://www.thoughtco.com/hypothesis-model-theory-and-law-2699066.

What are the Essential Features & Processes that Constitute Life?

Before we can describe how Life emerged from chemistry, we need to define the word “Life.”

One widely accepted definition of “Life” says that living organisms are open systems that have energy flow-through, perform metabolism, maintain homeostasis, grow, respond to stimuli, adapt to their environment, reproduce, evolve, are composed of a single cell or multiple cells, and have a life cycle from birth to death.

Re-stated as a list, this definition says that something is alive, it is a living organism, if (1) it is composed of one or more cells, (2) it has a life cycle – it is born, lives, and eventually dies, and (3) during its life it does all of the following things:

Each and Every Living Organism:

• Constructs and maintains a boundary that separates it from the outside.
• Channels a flow of energy through itself (i.e., it is a thermodynamically open system).
• Maintains homeostasis (described below)
• Has a metabolism – It takes in nutrients, extracts energy, and excretes waste.
• Moves and/or grows.
• Adapts to its environment.
• Responds to stimuli.
• Evolves – it can change over time in response to changes in its surroundings.

We can clearly see how interdependent all these functions are. An organism cannot move unless it has a boundary that separates it from its environment. It cannot move, self-maintain, grow, or reproduce without an energy flow. The organism can’t access energy without sensing and/or traveling to an energy source – its food. The food cannot enter the organism (nor waste exit it) unless the boundary is semi-permeable. The semi-permeable admits some new things and not others. There is an inherent tension between these two things: homeostasis and evolution. Things strive to stay the same, yet they evolve. Energy flows through day-to-day, but does not destroy the organism… until the organism dies and makes way for newborns that may display evolved features and abilities.

Are Viruses Alive?

What about Viruses?  Are they alive, or just “sort of” alive?

 Model of the coronavirus (Othocoronavirinae), from the Wikipedia article, “Coronavirus.” 

Viruses are not fully alive because they have no mechanisms for metabolism or reproduction. They do not have a cell membrane, just a coating. Viruses are pieces of genetic material (RNA or DNA) that have broken away from an organism and float around in the air and in the water. When they contact the cells of another fully alive organism, they infect them. Inside, they hijack that organism’s metabolic and reproductive systems, tricking the host organism into producing copies of the virus, which then escape into the world to infect the cells of other fully alive victims. Viruses are usually classified as “near living.” ²⁵. 

Note:  Viruses are parasites.  But so are human beings!  Everything we eat is or was another organism or a part of another organism.  We “harvest” (often meaning “kill”) that organism before we eat it. So, like viruses, we “parasitize” our environment.  On the other hand, the green plants we eat need us as much as we need them – we are co-dependent, each breathing in the other’s exhalations.

Note: In mentioning viruses, we are skipping ahead because science indicates that most viruses likely evolved from living things, even though the viruses themselves are not fully alive, because most of them cannot reproduce outside their host organisms.  (See: nature.com/scitable/topicpage/the-origins-of-viruses-14398218/.)

The Six Key Chemical Elements of Life on Earth

From the mightiest blue whale to the most minuscule paramecium, life takes dramatically different forms. Nonetheless, all organisms are built from the same six essential chemical elements, known by their first letters (“CHNOPS”):

1. Carbon
2. Hydrogen
3. Nitrogen
4. Oxygen
5. Phosphorus
6. Sulfur 

Among these six are the four elements that are both the most prevalent in the human body and the most common elements in the universe: Hydrogen, oxygen, carbon, and nitrogen. ²⁶

One thing that makes nitrogen, hydrogen, and oxygen so useful is that they’re abundant. They also exhibit acid-base effects, which allow them to bond with carbon to make amino acids, fats, lipids, and the nucleotide bases from which DNA and RNA are built. ²⁷ 

Life on Earth is Carbon-based

Professor Robert Hazen writes, “Everyone agrees that the element Carbon played a starring role.  No other element has such rich molecular patterns or such diverse molecular functions. Carbon atoms possess an unmatched ability to bond with other carbon atoms as well as to myriad other elements, notably hydrogen, oxygen, nitrogen, and sulfur, with up to four bonds at once. Carbon can form long chains of atoms, interlocked rings, complex branching arrangements, or almost any other imaginable shape.  It thus forms the backbone of proteins, carbohydrates, fats, and oils, as well as DNA and RNA. Only carbon-based molecules appear to share the twin defining characteristics of life: the ability to replicate and the ability to evolve.  Every morsel of food we eat, every medication we take, the bodies of every living thing, are loaded with carbon.” ²⁸ 

Earlier, we mentioned that crystals and the processes of crystal formation share several features with life and living systems. It is not surprising, then, that carbon is both the basis for life, and carbon can also form (under intense temperature and pressure) brilliant diamond crystals outside of living systems.

Carbon’s natural ability to grow by chaining its own molecules and by combining with other elements shows the tendency of pre-biological, non-living systems to form ordered structures, grow them, and increase their complexity.

However, as Dr. Hazen also writes, “Carbon cannot have undergone the remarkable progression from geochemistry to biochemistry by itself. All of Earth’s great transformative powers – water, heat, lightning, and the chemical energy of rocks – were brought to bear in life’s genesis.”  ²⁹

Other Chemical Elements Playing Important Roles in Life 

Magnesium is the eleventh most abundant element by mass in the human body and is essential to all cells and some 300 enzymes. Hundreds of enzymes require magnesium to function. 

Iron is a chemical element, a metal, and a naturally occurring mineral that is a critical component of hemoglobin, a protein that carries oxygen dissolved in our blood from our lungs throughout the body. It is the iron in our blood that gives it its red color. It helps our muscles store and use oxygen. Iron is also part of many other proteins and enzymes.

Sodium and Chlorine are each highly dangerous as raw elements. Sodium is explosive in the presence of water! Chlorine is a poisonous, lung-burning gas!  But with an easily added electron, chlorine becomes the far more prevalent Sodium Chloride (NaCl), i.e., common table salt — an important component of our blood. (Our blood is salty because we evolved from fish in the sea.) Sodium chloride is an example of the principle that when Nature’s Continuing Creation combines simple things together, it often creates a new thing that is quite different from its components — “The whole is different from the sum of its parts.”

The silvery-white metal, “Sodium.”

Calcium is a silver-gray metal that’s the fifth most abundant element in the human body. It plays a vital role in electrolyte balance, cell biochemistry, neurotransmission, muscle contraction, and fertilization. Calcium is important for protein synthesis and bone formation. Seashells are made of Calcium Carbonate, in the mineral form of calcite or aragonite. Sea-dwelling animals build their shells by extracting the necessary ingredients—dissolved calcium and bicarbonate—from their environment. ³⁰

Silicon-Based Life on Other Planets or Moons?

For decades, many futurists and science fiction writers have speculated that life on other planets in other solar systems might be based on silicon rather than carbon. Silicon is right below carbon on the Periodic Table of Elements, and silicon has almost as many ways to combine with other elements as carbon has. On Earth, silicon has already shown its versatility as the central element in the workings of electronics and computers. When computers “wake up” and become conscious entities in an expected event dubbed the Technological Singularity, they may become a “new species of life.”  For now, however, most scientists still place their bets on carbon as being central to all life across the cosmos. (For more on the Technological Singularity, see our Essay, Cyborgs, Transhumanism, and Immortality. See also the Wikipedia article, Hypothetical Types of Biochemistry.)

Chemical Evolution

We’ve said that before life began, there must have been a process of chemical change, a process of chemical evolution that preceded the process of life’s biological evolution. ^31 32

The prevailing scientific hypothesis is that the transition from non-living to living entities was not a single event, but an evolutionary process of increasing complexity that involved “chemical evolution.” Chemical Evolution is a relatively new term, and while it has various definitions, it encompasses the chemical creation of the three Monomers we discussed above – lipids, amino acids, and nucleotides – as well as the chemical creation of food molecules. 

As Dr. Nick Lane has written, “…The distinction between a ‘living planet – one that is geologically active – and a living cell is only a matter of definition. There is no hard and fast dividing line. Geochemistry gives rise seamlessly to biochemistry.”  ³³

Professor Hazen expressed a similar viewpoint when he wrote: “Molecular evolution, not intelligent design, is by far the fastest and most reliable path to achieving function. (That’s why we say that if God created life, she’s smart enough to have used evolution.)” ³⁴.

These quotations are consistent with Nature’s Path of Continuing Creation’s definition of Evolution as a set of linked processes that start with the evolution of stars and planets (if not earlier) and extend all the way through the “human-agented” evolution of culture and technology.

Inorganic Chemistry, by Itself, Often Behaves Like Life

The modern term, “chemical evolution,” has to do with the inorganic (non-carbon-based) molecules that are the precursors of life. We will talk about them shortly.

Simple observations of Nature, plus some high school chemistry and geology, reveal instances of non-biological growth and pattern formation that seem very much like the growth and patterns found in biological organisms. Many of us have observed that the branching patterns of river tributaries and river deltas are highly similar to those of trees forming roots and branches, as well as to the branching patterns of veins and arteries in human bodies. (See our Essay, Nature Creates Patterns of Information & Beauty.)

The mathematical series known as the Fibonacci Sequence (where, starting with “1, 1, 2, 3, 5, and 8…” each new integer is the sum of the previous two integers) produces the decidedly inorganic spirals of countless great rotating galaxies. This same number sequence also produces the decidedly organic spiral arrangement of the seeds in sunflowers and the spiral shape of a snail’s shell. (See our Essay, Mathematics Evolves in Nature’s Continuing Creation.)

High School chemistry taught many of us that the 92 natural chemical elements have combined to produce thousands of inorganic chemical compounds. Then, a subset of those same elements, working in conjunction with geology, evolves organic chemistry, which yields an even larger cornucopia of organic compounds and millions of different living species, each occupying a distinct niche in the Earth’s environments.

Amazingly, the human body is up to 60% water (H2O) by weight, and all four of the “Key Monomers” discussed in this Essay– lipids, amino acids, nucleotides, and (for aerobic organisms) monosaccharides — are mostly composed of the same chemical elements: argon, hydrogen, oxygen, sulfur, and sometimes potassium.  But those elements are arranged in different patterns that make the cornucopia of organic compounds found in living things. ³⁵ 

What is “Chemical Evolution”? 

As we mentioned, the term “chemical evolution” has not been clearly defined. ³⁶

• Some scientists adopt a narrow definition and say that chemical evolution is mainly about the following three types of processes seen in the life-like chemistry that can be found among inorganic molecules: 1) molecular self-replication, 2) self-assembly, and 3) autocatalysis. Some of these people elect to include the formation of lipid spheres (e.g., sea foam) in this definition.
• Other scientists take a broader view. They say that chemical evolution is the formation of complex organic molecules from simpler inorganic molecules through chemical reactions in the oceans during the early history of the Earth. “It was the first step in the development of life on planet Earth. The period of chemical evolution lasted less than a billion years.” (See “Chemical Evolution” at Dictionary.com.)

This second definition above is nearly identical to the definition of Abiogenesis, which we discuss further in Essay #14: Abiogenesis: Evolution of the First Life on Earth. But this definition of chemical evolution has organic molecules as its endpoint, whereas Abiogenesis has an actual First Living Organism as its endpoint. ³⁷

How Continuing Natural Creation Defines Chemical Evolution

A major theme of our book is that Nature’s Continuing Creation (NCC) is the grand construction of complexity, from the Big Bang through the ongoing evolution of cultures and technology, and into the future.

This grand construction can be divided into stages for ease of discussion, but in fact, all the stages, steps, and processes are highly interrelated.  For example, here is an acceptable division into Six Stages: 1. Cosmological Evolution of our Solar System and Earth, 2. Geologic & Climatic Evolution, 3. Chemical Evolution, 4, Abiogenesis, 5. Biological Evolution, 6. Cultural and Technological Invention & Evolution.

There are many principles and processes of NCC that are common to all its stages and steps.  A key example is the principle that the combination of things that are identical (or similar) can result in the creation of something amazingly new and different. 

As the ancient Greek polymath and philosopher Aristotle (384-322 BCE) famously said, “The Whole is greater than the Sum of Its parts.“  We might amend it to say, “greater than or amazingly different from.” (For more on this principle and others, see our Essay, The Processes of Evolution – and Their Meaning.)

Chemical Catalysis

Both Chemical Evolution and Biological Evolution (and maybe also Cultural & Technological Evolution) get an accelerating boost from the process of Catalysis.

Catalysis (in chemistry) is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst. Catalysts are not consumed in the catalyzed reaction but can act repeatedly. Often, only very small amounts of catalyst are required to achieve a quick and/or massive result. ³⁸

Chemical Catalysts are often used to speed up commercial chemical processes. The global demand for commercial chemical catalysts in 2010 was estimated at approximately US$29.5 billion. ³⁹

Three Examples of Catalysis in Inorganic (pre-biology) Chemistry:

1. The “Contact Process” speeds up the manufacture of sulfuric acid: When sulfur dioxide gas is passed, together with air, over a solid vanadium-oxide catalyst, its conversion into sulfur trioxide is sped up.
2. The “Haber Process“ uses iron as a catalyst to speed up the reaction of hydrogen and nitrogen to make ammonia.
3. The exhaust gases of cars are passed over transition-metal catalysts inside catalytic converters. These catalysts increase the rate of chemical reactions that turn exhaust pollutants such as carbon monoxide and unburnt fuel into gases and vapors that are less toxic.

When catalysts play a role in the processes of living cells, they are performing biochemistry — chemistry and biology at the same time. In the biochemistry of living organisms, enzymes are protein-based catalysts that act in the processes of cell metabolism. Most biocatalysts are enzymes, but other non-protein-based classes of biomolecules also exhibit catalytic properties. (See https://en.wikipedia.org/wiki/Catalysis#Illustration.) We will talk about Bio-chemical catalysis — for example, the “Krebs Cycle” (aka the Citric Acid Cycle), which releases energy from nutrients in the body, in later Essays.

The many instances of chemical catalysis demonstrate that inorganic non-living systems can self-organize and can self-reproduce in a way that is a harbinger of the ways that living organisms self-organize and reproduce. 

“Autocatalysis:” Same Definition for Organic & Inorganic Chem.

A single chemical reaction is said to be autocatalytic if one of the reaction products also serves as a catalyst for the same or a subsequent reaction. This definition holds for both inorganic chemistry and organic chemistry happening inside living organisms.

A set of chemical reactions can be said to be “collectively autocatalytic” if a number of those reactions produce, as reaction products, catalysts for enough of the other reactions that the entire set of chemical reactions is self-sustaining given an input of energy and food molecules (For more, see autocatalytic set).

Catalysts act as scaffolds and templates (i.e., as frameworks) for the construction of new catalysts. In this way, they are like crystals!

Lipids: They Form Outside of Life… and Also Inside Life! 

Life cannot exist unless it can separate itself from the world around it. There must be a boundary that separates the living creature from the non-living environment around it.  Without a boundary – an outer cell membrane — the outside world would contaminate and disrupt the delicate molecular chemistry within the cell. Compartmentalization was also necessary for the right interior chemical molecules to get close enough to each other to carry out their interactions.

> In the language of Physics, without such a boundary, the law of entropy (the Second Law of Thermodynamics) says that the cell’s organization and energy would dissipate out into the wider world and disappear. Similarly, in the realm of technology, every machine that successfully generates useful energy – a car’s motion, steam used to heat a building, electric current — has one or more boundaries that serve the same purpose. The boundary controls the energy, forcing it along a mechanical path, a controlled exit, that accomplishes work. An example is the steam boiler driving a piston in a locomotive. (See our Essay, “Mysteries of Modern Physics.”)

> In the language of Information Theory, if there are no boundaries, there are no differences. Without differences, there is no information, no variation… and therefore, no Creation. In essence, all Creation is the production of a difference that did not exist before. For more on this fundamental concept of our entire Practice and Path, see our Essay, “Nature Creates Patterns of Information & Beauty.”

Our aim in this Essay (the Essay you are now reading) is to show how the chemistry of Life can arise from non-living, inorganic chemistry. Evidence of this is seen in the fact that lipid spheres are often found in non-living locations of the natural world.

Every living thing is either a single cell or a group of cells (such as rose bushes and humans, which are huge, organized groups of cells). Every one of these cells is enclosed by a cell membrane. Inside each cell membrane, interacting molecules carry out the chemical processes of life, such as the oxidation (“burning”) of food sugars to generate energy, or the assembly of protein molecules to build muscle tissue. ⁴⁰.

Where Did Inorganic (non-living) Lipids Come From? 

Where did the pre-life lipids come from?  It had been thought that lipids could only be made by living organisms.  But recent experiments show that when CO, carbon-monoxide (simulating an ancient atmosphere), and H2O, water (simulating a little warm pool) are heated up with minerals currently found in Earth’s crust, lipids can form… on their own.  ⁴¹

Before life arose, picture the four chemicals essential for abiogenesis as floating in water, because life started in water. (The human body is itself 70% water.) Pre-life chemicals would not have been able to perform their functions unless they were protected from outside intrusion from other “foreign” chemicals and intrusions. ⁴²

The hollow lipid spheres that occur naturally in chemistry are the same as the hollow lipid spheres that are critical to the existence of all cellular life. This clear continuation of chemistry into biology demonstrates that the creation of First Life was not done by a sudden command from a mythical, anthropomorphic God but rather from the self-assembling, evolutionary Processes of Nature’s Continuing Creation: The Growing, Organizing, Direction of the Cosmos.        

When lipids are placed in water, the hydrophobic (water-fearing) tails aggregate to form micelles and vesicles, with the hydrophilic (water-loving) ends facing outwards. ⁴³

Primitive cells likely used self-assembling fatty acid vesicles to separate chemical reactions from the environment. Because of their simplicity and ability to self-assemble in water, these simple membranes likely predated other forms of early biological molecules. ⁴⁴ As a result, some biologists tend to equate the words “micelle” and “vesicle” with the term protocell.

Lipid molecules have a bulbous head on one end and a “tail” of acids on the other end. The bulbous end is “water-loving” (aquaphilic), while the trailing end is “water-hating” (aquaphobic).

Lipids like to coagulate, head next to head and tail next to tail, forming a uniform layer. Since the bulbous heads are wider than the acid tails, a lipid layer will naturally curve in on itself to form a sphere. The bulbous heads face outward, and the acid tails dangle on the inside.

The formation of these layers and spheres is an automatic process of self-assembly – no outside direction or manipulation is required. 

Lipids naturally encapsulate small volumes of water.  If that water contains the other monomers of life we listed above, the amino acids and the nucleotides, then the sphere could be called a protocell, which is a non-living precursor to the first living cell(s). This possibility is, in fact, one of the leading models (theories) about how Life began. And as we have said, the cell membranes of all organisms living today are still composed of lipid layers.

When there is water both outside and inside the sphere, the lipids can form a double-layered (bi-layered) sphere: One layer has its bulbous heads facing outside toward the world, and a second layer has its heads facing inward toward the interior. Between those two layers, all the trailing chains of the molecules end up facing toward each other. The whole assembly is like a peanut butter sandwich rolled into a hollow ball. Some “bread” faces outward and some inward, while the “peanut butter” is sandwiched in between the two spheres of bread.  In biology, these spheres are called micelles, and if they are bilayered, they are called vesicles. A vesicle that was man-made in the laboratory, e.g., for use in the intravenous delivery of drugs, is called a liposome.

We Easily Find Lipids in Seafoam & Soap Bubbles

Spherical Lipid enclosures frequently stack together to form sea foam and soap bubbles. Both sea foam and soap bubbles have their origins in the remains of living things. Seafoam and soap bubbles are made of lipids that have an organic origin, such as animal fats and algae, including disintegrating seaweeds. The lipids’ spherical shape and their tendency to self-assemble in layers are natural. There is no outside manipulation, no outside intelligence giving them directions to do this. ⁴⁵  

Sea foam, or “spume,” is created by the agitation of seawater when it contains concentrations of dissolved organic matter. Due to its low density and persistence, foam can be blown by strong winds blowing from the sea and reaching tidal pools on the beach.  ⁴⁶

In ancient Babylon and Sumer, people made soap by mixing ashes with water and fat and boiling them. Their soap was actually a solution of ash, oily fats, and water.  Under a microscope, a froth of small soap bubbles looks a lot like a slice of living tissue. (See Wikipedia, “Soap.”)  Just like the lipid membranes we discussed above, “A soap molecule consists of a polar ionic hydrophilic (water-loving) end, and a non-polar hydrophobic (water-hating) end. When dissolved in water, the soap molecules arrange themselves in roughly spherical aggregates of 60 or so molecules, called surfactant micelles. (See the Wikipedia article on “Soap.”)

Crystals Are Not Alive, But They Can Form a Structure & Grow

Crystals consist of a regular, geometric lattice of atoms. Each crystal lattice can grow if it is placed in water laced with the same chemical components. The adjacent free-floating atoms bump into and automatically attach themselves to the crystal edge, enlarging the crystalline form.

Geodes are another example of inorganic chemicals – rock minerals, in this case, that form enclosures permitting ordered structures to grow inside them. Beautiful crystals can grow from slow precipitation on the inside of the hollow rocks, creating geodes. While it is forming, every geode is completely enclosed by a protective rock barrier wall which acts a lot like the cell membrane that surrounds every living cell.

Many crystals inside geodes are shaped like hexagonal columns that point inward toward the center of the geode. Often, such a six-sided column will begin to taper to a faceted point. How is that “decided”? How does each of the six faces “know” to start doing that at the same time, so that the point is reached at the center of the column? The crystal has no brain with which to decide or to know, but the behavior is life-like.

Amethyst Crystals Inside a Geode

While sea foam and soap bubbles are made of lipids, which usually (but not always!) have had their origin in some formerly living organism, rock geode crystals are clearly not by-products of living things, yet geology can form enclosures that permit and protect ordered structures to grow inside them, just like living cells do. Later, in the fourth Essay (Essay #14) of this series, we will describe the “Silicate-Clay Crystals Model” of the Origin of Life — one of the eight scientific models of where the first cells were born.

The crystals inside geodes form by the partial filling of geological vesicles (hollow cavities) in volcanic and sub-volcanic rocks with minerals deposited from hydrothermal fluids such as mineral-rich water.

Note: The forts and castles of ancient cities and baronies also have surrounding walls. So do wasps’ nests, and insect cocoons. The “keep,” the inner, most-protecting  fort inside a medieval castle wall, is like the nucleus in a eukaryotic cell, i.e., “a cell that has a nucleus.” – J.X. Mason

There Are Even Crystals Inside Living Things!

Not only do crystals act like living things, but the key molecules of living things — amino acids, proteins, nucleic acids, RNA, and DNA – can all adopt important crystalline structures. See our next Essay, “The Organic Molecules & Processes that Form Life.” ⁴⁹

Diatoms Make Silica Cell Walls that Are Similar to Crystals.

Since quartz crystals and many other mineral crystals are primarily made of silica (i.e., silicon dioxide), we must talk about the tiny single-celled living creatures called diatoms that form their outer cell walls using silica. In other words, diatoms make their outer walls out of a mineral that also makes up a great number of quartz rocks.

  Magnified photo of Diatom shells.  

Diatoms are a type of microalgae found in oceans, waterways, and soils worldwide. Like green plants and other green algae, diatoms convert light energy to chemical energy by photosynthesis, although this shared capability evolved independently in both lineages. Diatoms generate about 20 to 50 percent of the oxygen on the planet each year. ⁵⁰ They take in over 6.7 billion metric tons of silicon each year from the waters in which they live and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor. ⁵¹

The silica cell walls of diatoms are called frustules. These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as
“jewels of the sea” and “living opals.” Frustules are both hard and porous, and they are coated with a layer of organic substance composed of several types of polysaccharides. ⁵² The frustule’s structure is usually composed of two overlapping sections that allow for some internal expansion room and are essential during the reproduction process. The frustule also contains many pores and slits that provide the diatom access to the external environment for processes such as waste removal and mucilage secretion.

Seashells Are Mineral Structures Made by Living Organisms

Analogous to the outer walls of diatoms, seashells are also made of minerals. Thus, while we usually think of minerals as something that organic processes use to make living things, seashells are the opposite – they are minerals made by living organisms. Seashells, however, are not crystalline.

The Evolution of Beauty

Seashells, like diatoms, mineral crystals, and flowers, display many geometric shapes and/or colors. These shapes and patterns show that evolution, when conditions are right, is quite capable of producing geometrical beauty. See our Essay, “Nature Creates Patterns of Information & Beauty.” 

Humans also find beauty in the plumage of birds, the fur of animals, and the coloration of tropical fish and coral reefs. Some biologists argue that there is a tendency in evolution toward beauty, primarily because it influences the selection of mates.  It is also possible that the evolution of flower beauty to attract birds co-evolves with the evolution of bird beauty to attract mates. The two evolutionary mechanisms reinforce each other. Working together, both trends would produce more flowers and more birds.  If so, this coevolution is very much like catalysis in chemistry, because the mutual reinforcement in each stimulates the speed of production. We talk about this topic in the next Essay, i.e., Essay #12, in this set of four Essays.

Biologists have written best-selling books around this Evolution of Beauty topic, including Professor Sean B. Carroll’s Endless Forms Most Beautiful. ⁵³ and Professor Richard O. Prum’s The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World – and Us.  ⁵⁴

“Liquid Crystals” are a state of matter that has properties between those of conventional liquids and those of solid crystals. For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way… Examples of liquid crystals can be found in both the natural world and in various technological applications. Widespread Liquid-crystal displays use liquid crystals. Many proteins and cell membranes are liquid crystals. Other well-known examples of liquid crystals are solutions of soap and various related detergents, as well as the tobacco mosaic virus, and some clays.” (From the Wikipedia article on Liquid Crystal.)

Photograph of Liquid Crystals

In 2007, a team led by researchers from the University of Colorado at Boulder and the University of Milan discovered unexpected forms of liquid crystals formed by ultrashort DNA molecules immersed in water, providing a new scenario for a key step in the emergence of life on Earth. ⁵⁵.

Colorado Physics Professor Noel Clark and his team found that surprisingly short segments of DNA, life’s molecular carrier of genetic information, could assemble into several distinct liquid crystal phases that “self-orient” parallel to one another and stack into columns when placed in a water solution. (Life is widely believed to have emerged as segments of DNA-like or RNA-like molecules in a prebiotic ‘soup’ solution of ancient organic molecules.)  ⁵⁶

Supramolecular Assemblies

We can generalize even further. Liquid crystals and soap bubbles are both examples of Supramolecular assemblies. So are biological membranes, liposomes, colloids, biomolecular condensates, lattices, micelles, and even helical liquid crystals such as RNA and DNA. ⁵⁷. The chemical compositions of such assemblies are not solely responsible for their unique properties. Rather, their unique properties also depend heavily on their specific ordered spatial structures. For more on this topic, see our Essay, “Nature Creates Increasingly Complex Systems.” 

All these structures are held together by loose, non–covalent chemical bonds, which are weaker than the covalent bonds that hold atoms together to construct a molecule. There are so many structures and systems today that are alive, or at least act like they are alive, that a modern interdisciplinary branch of science, Supramolecular Chemistry, studies all of them together. ⁵⁸ Supramolecular Chemistry is the branch of chemistry that specializes in non-covalent interactions. These weak and reversible forces — such as hydrogen bonds, hydrophobic effects, van der Waals forces, and “metal-ligand cooperativity” — are key to understanding both biological processes and inorganic self-assembling systems. ⁵⁹

Self-replication Among Non-Living (Inorganic) Chemicals!

In the next Essay, The Molecules that Form Life (the Second Essay in our Part Four Series of 4), we will see that DNA and RNA, which carry an organism’s encoded hereditary information, are organic molecules that can self-replicate, while all the other organic molecules need help from adjacent molecular machinery. For example, amino acids get replicated, but only as directed by RNA (an “unzipped” half of DNA).

However, there are examples of chemical molecules self-creating outside of living organisms.  Here are two of those examples:

Example #1 — “Life makes more of itself. And now, so can a set of custom-designed chemicals. Chemists [Gerald Joyce and Tracey Lincoln] have shown that a group of synthetic enzymes replicated, competed, and evolved much like a natural ecosystem, but without life or cells… The researchers began with pairs of enzymes they had been tweaking and designing for the past eight years. Each member of the pairs can only reproduce with the help of the other member.” From there, Joyce and Lincoln added the enzymes into a soup of building blocks, “short strings of nucleic bases….and tweaked them to find the base pairs [that would allow the enzymes] to reproduce…. When the scientists introduced them into a larger soup mix, a new set of mutants emerged that were more adept at replicating within the system. It worked almost like an ecosystem, but with just straight chemistry.” — Alexis Madrigal  ⁶⁰

Example #2 –“Although self-replication is usually associated with DNA, the behavior has been seen in very different-looking chemical systems – for example, in rotaxanes [tiny molecular assemblies shaped like a ring around an axle, where the axle is capped at each end to keep the ring from sliding off]. This raises the intriguing possibility of creating completely synthetic lifeforms that tick all three boxes for life: replication, i.e., the use and storage of energy to perform reactions that require outside energy, while keeping all of these functions contained to protect them from parasitic lifeforms.” ⁶¹

Footnotes: