THE ORIGIN OF LIFE

The existing interpretations

Creationism (reinvented recently as ‘Intelligent design') that adheres to the Biblical account of the origin of life is still seen in some places as an alternative to the materialist view, so it is worth briefly addressing this position. Creationists are very good at criticising the opposite standpoint, but not in providing a coherent support for their own. Genesis is clear that the creation of life is a deliberate act, but the way it is presented has many problems. Without getting into details, a general one is the claim that an agency assembled various species as discrete units. This does not seem plausible. All paleontological and micro-biological evidence indicates that life, in all its diversity, originated from very simple forms and evolved through a long period of time. Contrary to the creationist account, it is evident that more complex organisms have derived from simpler ones, and that there are big time gaps between the appearance of various species. This is not to say that life is an accident, as materialists would like to believe. The following is an attempt to show that such a claim is also problematic.

 

Materialism - from the materialistic perspective, the origin of life is explained as a chance event that occurred through the interplay of physical forces and chemical reactions. The idea that life came about accidentally from inanimate matter should not be taken for granted, though[1]. Contrary to popular belief, this account is not proven, empirically or rationally. It has never been demonstrated in a laboratory or anywhere else that a complex structure such as a living cell could arise spontaneously (or through human intervention) from inorganic stuff.  Honest scientists are ready to admit this:

We have not yet come up with a convincing mechanism for abiogenesis... And we have come nowhere near creating life in the laboratory. (Silver, 1998, p.339)

In the 1950s Stanley Miller recreated the conditions believed to exist on prebiotic Earth (a mixture of methane, ammonia, hydrogen and water was exposed to heat and occasional spark-discharges). In a relatively short time Miller found some amino-acids in the apparatus (amino-acids are the building blocks of proteins that are in turn the basis of organic life). Recent findings suggest, though, that life arose in an environment far less hospitable than Miller's glass apparatus. Moreover, many experiments since have not gone much further. Apparently, some researchers managed to create a synthetic organic molecule that could replicate itself, but this should not be confused with procreation. They only replicate in highly artificial, unnatural conditions, and they reproduce only exact replicas. Yet, without mutations the molecules could not evolve.

Not only has materialism failed to produce a convincing support for its position, but it is also internally inconsistent. Biogenesis is an accepted doctrine in biology, which states that living organisms are produced only by other living organisms, and that the parent organism's offspring are always of the same kind. Abiogenesis (the notion that life can appear from non-life) is only assumed for the beginning of life, when apparently the first living organism was accidentally generated from inanimate matter. This inconsistency is accepted not because the available data is in its favour, but because it fits current ideology. In his book The Intelligent Universe mathematician and astronomer Fred Hoyle asks:

...there is not a shred of objective evidence to support the hypothesis that life began in an organic soup here on the Earth. Indeed, Francis Crick, who shared a Nobel prize for the discovery of the structure of DNA, is one biophysicist who finds this theory unconvincing. So, why do biologists indulge in unsubstantiated fantasies in order to deny what is so patently obvious, that the 200 000 amino acid chains, and hence life, did not appear by chance? (1983, p.21)

Indeed, it has been calculated that accidental abiogenesis is extremely unlikely, even if millions of years were available (see, for example, Overman, 1997). According to palaeontologist Fondi, ‘a spontaneous assemblage of molecules driven by chance cannot account for the emergence of complex organisms - even the oldest algae and bacteria are too complex to have resulted from chance processes in the observed time frames' (in Laszlo, 1993, p.100). In order to survive and reproduce, a one-cell organism, however simple, requires at least several components, RNA, (and/or DNA), some proteins and a cell membrane. Furthermore, they all need to function in a synchronous way. Let us consider how likely this is if left to chance.

  • [1]. Silver, a biochemist himself, comments: ‘One can believe that a complex system like the living cell is capable of manufacturing large, complex molecules from small, simple precursors, but the original manufacturing mechanism has to come from somewhere' (1998, p.340).

The necessary conditions for the cell formation

Molecular properties - a functional cell requires many polymers, large long-chain molecules, built from a number of simple molecules (monomers). These molecules can hardly form spontaneously for several reasons. The formation of polymers requires bifunctional monomers (i.e. those that can combine with two others), and can be stopped by a small fraction of unifunctional monomers (those that can combine with only one other, thus blocking one end of the growing chain). Prebiotic simulation experiments produce five times more unifunctional molecules than bifunctional ones. Furthermore, many polymers (such as proteins, DNA or RNA) come in two forms, ‘left-handed' and ‘right-handed'. The building blocks of polymers essential for life need to have the same ‘handedness' - proteins consist of amino acids that are all ‘left handed', while DNA and RNA contain sugars that are only ‘right-handed'. Under the right conditions, an undirected environment that operates solely on the principles of physical chemistry can produce amino acids, but they are wrong for life. So created molecules are a blend of left and right hand forms, not the pure ones needed in living things. They could not form the specific shapes required for proteins, and DNA could not be stabilised in a helix and support life if just a small proportion of the wrong-handed kind was present. To produce the correct types of amino acids and sugars, life requires a certain type of proteins called enzymes. However, these complex molecules do not appear spontaneously, they can only be manufactured in a living cell. An equivalent of such a molecular machinery though, did not exist in the pre-life environment.

 

The cell components - even if all the right ingredients are present, there is still the problem of forming a functional cell components by random processes. Proteins and other structures necessary for life consist of many building blocks which must be instantly put together in a certain order. Out of a total number of possible protein structures (within an appropriate size range) only a tiny set have the correct properties from which a simple bacterium can be successfully built. The odds that they will be formed purely by chance is infinitely small. Let us consider the above mentioned enzymes. Just one is typically comprised of 300 amino acids. Even if it is assumed that a much smaller number of amino acids is needed to form a ‘primitive' enzyme, the probability of the required order in a single functional protein molecule arising randomly is estimated at 1043 (this is a modest estimate, some go as far as 10195). The simplest living cell must have at least several hundred enzymes and other proteins, which makes a chance arrangement of these molecules extremely unlikely. Silver writes that ‘the probability of a crowd of small molecules forming the needed large molecules to start the long, complex path to a single cell seems to be almost zero' (1998, p.349).

 

The cell membrane - the other necessary component of a living cell is the cell membrane. A universal ingredient of all cell membranes is the phospholipid molecule. This molecule can spontaneously form vesicles in water (‘bubbles' that resemble in shape the cell membrane), but no one has managed to reproduce this in the experiments that attempt to simulate conditions on the Earth when life began. Moreover, the cell membrane does not only maintain the physical unity of the cell, but also performs other vital functions (e.g. allowing energy exchange)[2]. This all requires a relatively complex structure even for the simplest imaginable functional cells that is highly unlikely to be a result of random chemical reactions.

 

Functioning of a cell - the above evaluates only the necessary parts, not a functional arrangement, i.e. one that works. Even if it is accepted that the components of a living cell were somehow formed accidentally, that would not be enough[3].

The simplest one-cell organism represents a level of complexity not found anywhere in the inanimate world including that created by humans (viruses, that  are, roughly speaking, DNA coated in a protein, do not count, because they need other more complex cells to reproduce, so they could only appear or degenerate to this simplicity later in evolution).

All the components of a living cell need to be synchronised, to act in a union in order to maintain a cell. So, a cell cannot be built piecemeal, all the major constituents must have been created and assembled instantaneously for the cell to function. Without elaborate mechanisms that enable energy intake, chemical distribution, processing of proteins, and storing of genetic information to be passed on to the next generation, life could not exist.

So, the components on which these processes depend could not have evolved separately. Proteins cannot form without DNA, but neither can DNA form without proteins.  Moreover, they could not exist independently for very long:

The large and complex molecules essential to life - proteins with dozens of hundreds of amino acids, RNA and DNA formed with long chains of nucleotides - do not appear spontaneously, even in carefully devised environments with high concentrations of monomers. Indeed, these macromolecules appear to be quite unstable. Even when two monomers link up or polymerise, they often will just as quickly disintegrate or depolymerise under water-rich conditions. (Hazen, 1997, p.165)

Most nucleotides (essential cell components) degrade fast at the temperatures that apparently existed on the early Earth. Polymers also quickly break down in water (water absorbing chemicals or evaporating water by high temperature would require either unrealistic conditions or would lead to the destruction of the polymers necessary to form a cell). This means that not only did they all need to be produced close to each other, but also within a very short period of time. DNA (and/or RNA), some proteins and cell membrane need to be formed at the right time and place and under the right conditions. However, as Silver point out:

It stretches even the credulity of a materialistic abiogenesis fanatic to believe that proteins and nucleotides persistently emerged simultaneously, and at the same point in space, from the primeval soup. We are in trouble enough without adding events of an astronomical improbability (1998, p.347).

Even if this was the case, many of the important biochemicals would, in fact, destroy each other (i.e. sugars and amino acids mutually react). Living organisms are well-structured to avoid this, but the ‘primordial soup' would not be. In other words, the cell is born out of co-ordinated complexity, not out of chaotic complexity.

The above indicates that an accidental beginning of life is implausible. Even a hard-line  materialist, such as Crick, admits that ‘the origin of life appears to be almost a miracle, so many are the conditions which would have had to be satisfied to get it going' (in Silver, 1998, p.349).

  • [2]. Some of its properties seem to even anticipate complex life forms: ‘...the cell membrane is uniquely and ideally fit for its role of bounding the cell's contents and conferring on the cells of higher organisms the ability to move and adhere selectively to one another. These critical properties are also dependent on the size of the average cell being approximately what it is and on the viscosity of cytoplasm being close to what it is. The membrane is also fit, in that its selective impermeability to changed particles confers additional electrical properties, which form the basis of nerve conduction' (Denton, 1998, p.209).
  • [3]. To quote Silver again, ‘the basic problem facing anyone who is looking for the origin of life is to account for the formation of a complex, very highly organized, self-sustaining and self-replicating system out of a mixture of chemicals that, certainly in the early days of the soup, displayed none of these characteristics' (1998, p.340).

Some current hypotheses

The popular argument is that, given a very long period of time, life would occur, even if the chance of its appearance is minuscule. However, ‘it seems that life appeared almost as soon as the planetary hydrosphere had cooled sufficiently to support it. The time available is certainly short - nothing like the supposed thousands of millions of years that was once assumed to be available’ (Denton, 1998, p.295). Not surprisingly, many scientists are at a pain to find an explanation which would overcome the problems that the above facts create for the materialistic perspective. Crick, for example, hypothesises that life came from outer space (as the Sumerians and a Greek philosopher Anaxagoras believed much before him). Even if this is true, it does not solve the problem, but only moves it elsewhere. Some scientists speculate that the original cell or cells were much simpler than the simplest existing one-cell organisms. For example, it could be the case that RNA at one point was not only a messenger but also a replicator (therefore assuming the role of DNA too). However, this possibility faces several difficulties. RNA is hard to synthesise even under controlled circumstances, with all the help of scientists, let alone in the conditions in which biological life was formed. Even when RNA is manufactured, it requires much tinkering to make new copies of itself: ‘...the synthesis of RNA by chance is a highly improbable process, and as yet no one has presented a mechanism by which it might have occurred... even when you do have RNA, the process of self-replication in the laboratory is not at all straightforward, and it requires considerable intervention on the part of the experimenter’ (Silver, 1998, p.348). Intervention, however, is exactly what materialists deny in regard to the origin of life. There are a number of other alternatives, but none of them is very credible. It is not possible to examine all of them here, so the final comment is left to an evolutionary biologist who already did so:

Although many exotic hypotheses far more speculative than the RNA world have been proposed to close the gap between chemistry and life, none are convincing. (Denton 1998, p.294)

That an accidental appearance of life is extremely unlikely seems to be the inevitable inference. Polanyi and Prosch conclude that ‘every living organism is a meaningful organization of meaningless matter and that it is very highly improbable that these meaningful organizations should all have occurred entirely by chance’ (1975, p.172). The above does not, of course, provide a definitive proof that a teleological explanation is correct. This is not essential though. Declaring that life must have come about by chance simply because there is no concrete evidence for an agency, would be like declaring that a sculpture is the result of a natural process because the sculptor cannot be seen. In the words of the astronomer Carl Sagan, ‘absence of evidence is not evidence of absence’. On the other hand, however dismally small the chance of accidental abiogenesis is, it is not entirely impossible that such a fluke may have happened. There might be some purely physical factors, not yet discovered, that could greatly increase the probability of a spontaneous formation of life. Thus, although the involvement of an agency seems a more plausible explanation, it cannot be conclusively proven, so the choice to accept this possibility or not is preserved. What is important, however, if a teleological position is to be taken seriously, is to examine whether it can be interpreted in a rational way.

THE SYNTHESIS PERSPECTIVE

It seems equally unlikely that life was created accidentally and that an agent acted/acts like an engineer, putting various parts together or programming DNA sequences. A more plausible explanation that combines spiritual and scientific insights (without their religious and materialistic baggage) is that life was intended. As suggested earlier in relation to the tuning of the four forces and other physical properties, ‘design' or the direct involvement of an external agency need not to be invoked. In accord with the criterion of cohesiveness, it is sufficient to postulate as the most likely explanation an intended abiogenesis. The Intent acts, on one hand, as a driving force pushing the matter into more complex organisation and, on the other, as a restricting force, a ‘funnel' that converges a huge number of possibilities into one point - the appearance of life[1]. Of course, there could not be direct evidence for such an intent (it cannot be expected that the One would leave ‘fingerprints'). However, there are some suggestive indicators, making this explanation more likely than highly improbable chance. They include the distinctive properties of the building blocks that enable the formation of complex forms conducive to life, and finely tuned (physical, chemical and environmental) conditions. Several examples will be brought up to illustrate this.

It is not only the physical forces, constants and solar objects that are precisely adjusted to enable life, but also many physical and chemical properties, established much before life appeared, are uniquely fit for carbon-based organisms. Biologist Denton (who is not associated with Creationism or similar movements) should be credited for collecting comprehensive and compelling evidence that life is unlikely to be an accident. He points out that life could not exist if ‘various constituents - water, carbon dioxide, carbon acid, the DNA helix, proteins, phosphates, sugars, lipids, the carbon atom the oxygen atom, the transitional metal atoms and the other metal atoms from groups 1 and 2 of the periodic table: sodium, potassium, calcium, and magnesium - did not possess precisely those chemical and physical properties they exhibit in an aqueous solution ranging in temperature from 0ºC and about 75ºC' (1998, p.382).

Let us consider water, for example, arguably the most important substance for life. Water is very unusual. While most substances shrink when cooled, water starts expanding (below 4°C) so solid ice is atypically less dense than liquid water. Water is also extraordinary slow in warming up - another anomaly. What is amazing is that all this and many other characteristics of water (e.g. the low viscosity, the surface tension, the capacity to dissolve a vast number of different substances, etc.[2]) are beneficial to life. For example, if ice was heavier (more dense) than water, the oceans would have frozen completely, killing all marine life; the slow warming up of water protects organisms against massive swings in temperature, and so on. Scientists find it hard to explain many of these properties. They are most likely linked to hydrogen bonds between water molecules, and they again depend on zero-point vibration energy - energy from ‘nowhere'.

Many other physical and chemical features are also well adjusted for life. For example, carbon (the building block of organic matter) has a whole range of such properties: maximum utility of both the strong covalent bonds (that keep atoms together) and the weak bonds (e.g. hydrogen bonds) in the same temperature range at which water is fluid; the perfect fit between the α helix of the protein with the large groove of the DNA; the relative stability of organic molecules below 100°C; the relatively un-reactive nature of oxygen, a source of energy for carbon-based life, below 50°C; the fact that carbon dioxide is a gas (which enables the excretion of the products of carbon oxidation); the sufficient strength of hydrogen and other weak bonds to hold proteins and DNA at temper­atures conducive to life, and so on. Moreover, atmospheric gases (including water vapour) and liquid water, absorb virtually all the harmful radiation from space and transmit only a tiny band that is of visual range and is at the same time, fit for photochemistry. Also, all the classes of atoms in the periodic table play a harmonious role in the formation and sustenance of life. Adaptation of life to these circumstances is not a sufficient explanation. If only a few of them had not been already there, life would not have had a chance to adapt to anything. In addition, these properties are not only conducive to the appearance of microorganisms, but seem to anticipate more complex multicellular life forms. To quote Denton again:

Many of the properties and characteristics of life's constituents seem to be specifically arranged for large, complex, multicellular organisms like ourselves. The coincidences do not stop at the cell but extend right on into higher forms of life. These include the packaging properties of DNA, which enable a vast amount of DNA and hence biological information to be packed into the tiny volume of the cell nucleus in higher organisms, the electrical properties of cells, which depend ultimately on the insulating character of the cell membrane, which provides the basis for nerve conduction and for the coordination of the activities of multicellular organisms; the very nature of the cell, particularly its feeling and crawling activities, which seem so ideally adapted for assembling a multicellular organism during development; the fact that oxygen and carbon dioxide are both gases at ambient temperatures and the peculiar and unique character of the bicarbonate buffer, which together greatly facilitate the life of large air-breathing macroscopic organisms. (1998, p.381-2)

One can also add to the list the decrease in the viscosity of the blood when blood pressure rises, which increases the blood flow to the metabolically active muscles of higher organisms (without it, the circulatory system would be unworkable); the quite slow hydration of carbon dioxide, which prevents a fatally high level of acidity in the body of complex organisms in anaerobic exercises (that require increased pace or greater effort). Curiously, only atmospheres with between 10 and 20% oxygen can support an oxidative metabolism in a higher organism; and it is only within that range that fire - hence technology - is possible. As Denton puts it,

...for every new constituent we required, there was a ready-made solution that seemed ideally and uniquely prefabricated, as if by design, for the biological end it serves... (1998, p.230)

Even those phenomena that are taken as calamities, are, in fact, often purposeful. For example, volcanic eruptions bring water and metals to the surface, contribute to the atmosphere, regulate heat, and finally, fertilise the land, enabling agriculture.

Without going into further details, it can be concluded that it is consistent with the Synthesis perspective that life started from very simple forms, as scientists claim too. Whether it originated in a ‘primeval soup', in hot-water vents at the bottom of the ocean, in clay sediments, or on Mars, is a technical issue that does not affect the basic assertion, which is that life being intended is not only congruent with the known facts, but highly probable. The above indicates that life could hardly appear by chance, and that the funnelling of randomness was necessary.[3] This is all that can be claimed at this point (the process that led to the beginning of life will be considered on p.149). To make further inferences about the appearance of life as we know it, the question of what life is, what it consists of, needs to be addressed first. This issue (that will require the examination of some complex aspects of human life) will be the subject of the following part.

  • [1]. Later on, in evolution, a divergent process takes place (analogous to the Big Bang explosion, after the energy had been first compressed into singularity). So, different principles govern the proliferation of various life forms (see chapter 16).
  • [2]. Professor Martin Chaplin listed over 40 anomalous characteristics of water.
  • [3]. It is sometimes claimed (e.g. Dawkins, 2006, p.138) that even if the chance is one in a billion, providing that there are a billion planets in the universe, life will appear at least on one of them. This argument is based on either misunderstanding or misuse of statistics, so it does not deserve a serious consideration.