Where Did Life Come From?

Among those who reject the Biblical record of God’s action in creating everything, including all living things, the process of chemical evolution from atoms to the first cell is usually explained something like this: elements reacted with each other spontaneously forming simple molecules. These simple molecules continued to react forming larger and more complex molecules such as the nucleotide building blocks of nucleic acids. Building block molecules continued reacting, forming proteins, nucleic acids and so on, some of which happened to start associating together due to chemical attractions in such a way that they commenced reproducing themselves and that was the spark of life from which all living things descended.

It is tempting, and in fact it has been done many times, to pick apart this materialistic mythology, pointing out scientific problems at each hypothetical step along the way. Another natural response is to ask for some kind of evidence, perhaps fossil molecules intermediate between living cells and non-living chemicals. While this evidence appears to be lacking, Christians may point to the historical record of Jesus Christ, the Creator Himself, who came down to Earth and demonstrated his power over nature, particularly his power over death. Materialists are left only with a faith, uncluttered in its purity by relevant evidence. Something like chemical evolution has to have happened according to materialistic thought because any Creator God is excluded as a possibility and life is here, so it must have come about by “natural” means.

For the sake of brevity, we will look at only two characteristics of life, both of which are problematic for materialistic explanations and are well explained by a kind of brilliance that we humans have yet to come close to emulating. The first of these is the universal association of water with living things, the second the integrated nature of life.

Water makes up the bulk of most cells, although some cells store large amounts of other materials such as fat or starch. Still, free-living cells are generally composed primarily of water, which acts as a necessary solvent for minerals, proteins and other cellular components and may serve other purposes.

Water is so universally associated with life as we know it that it is considered to be essential for life. It is a good thing that water is so abundant on the earth, but its presence poses a serious challenge to the hypothesis that biological macromolecules were formed spontaneously before life existed. The problem is that the major biological macromolecules – proteins, nucleic acids, polysaccharides and triglycerides – are all formed via condensation reactions in which a water molecule is removed during the process of forming the bonds that hold them together. For example, when an amino acid is added to the end of a growing protein, a water molecule is removed when the connecting peptide bond is formed. This means that these macromolecules will be broken down again if the reaction is reversed and a water molecule is inserted back into the bonds connecting their subunits.

In the presence of abundant water, biological macromolecules formed by condensation reactions – proteins, nucleic acids, polysaccharides, triglycerides – spontaneously break down; they do not spontaneously make themselves. Even if catalysts are added that speed up the rate of bond formation, they also increase the rate of the reverse reaction. The only way to make the macromolecules essential to life is by harnessing energy and using it to do the work of driving chemical reactions in the direction opposite to the one they spontaneously go in. Human beings have managed to do this using complex laboratory procedures and equipment, so we know at least in principle that it is possible for intelligent beings to synthesize the macromolecules of life. We also know, from studying the molecular machines inside cells, that cells are composed of complex machinery that does this. What we don’t see are examples of these reactions occurring outside of these two scenarios. The closest may be some chemicals recovered from meteorites, but even if meteorites supplied the raw materials for life on earth, the presence of water will break them down over time, not serve as a medium for them to form ever more complex and integrated systems.

Because water is universal to life and the molecules from which life is composed do not spontaneously form in the presence of water, but in fact break down, materialistic scenarios involving a gradual accumulation of complexity appear to lack a sword in their arsenal to cut this biochemical Gordian knot.

A second issue with materialistic origin of life scenarios is the assumption that it is possible in principle for a single simple life form to exist alone. In nature no example of this has been observed. Life is characterized by its interdependence on other life. It may be argued that bacteria can be grown axenically, in the absence of other organisms, but this is not really true. When pure bacterial cultures are grown on agar (a product of seaweed) plates or in liquid culture, they require sources of carbon and nitrogen among other nutrients. These are isolated from other organisms and are supplied in the growth medium by the scientists who are culturing bacteria or other cells.

Interdependence is illustrated nicely by the interaction between humans and the organisms inhabiting our gut. When we think of ourselves, we typically think of just the human cells from which we are composed, but the human body actually contains more non-human cells than human cells.[1] This may seem startling, but many of the non-human cells are bacteria and bacterial cells are, on average, considerably smaller than human cells. The flora living in the intestines of a healthy human contains a variety of bacteria that appear to aid in digestion. The human microbiome appears to be essential to good health, possibly to life itself. It also forms the basis of an entire industry selling “macrobiotics” designed for optimal bowel health.

The amazing thing is that humans don’t normally need to purchase industrially produced bacterial cultures to manage the flora of their gut. It is all done automatically most of the time, although anyone who has experienced a perturbation in their gut flora probably found it to be a memorable experience. How do these bacteria become established in our guts? A particularly elegant cooperation was recently discovered between babies and bacteria that allows this to happen.[2] It used to be thought that babies were born with immature immune systems and were thus prone to various infections. This might look like a design flaw, but in fact, something much more interesting is going on. It appears babies are born with immune systems that are quite capable of fighting infections, but they dial it back to allow healthy bacteria to colonize their guts without eliciting a massive immune reaction that would compromise the health of the baby and possibly prevent development of a healthy gut flora. In fact, gut inflammation commonly observed in premature babies may be the result of an immune system not ready for gut colonization and thus over reacting to gut colonizing bacteria.

The dialed-back immune system of newborn babies is not a design flaw, but rather an elegant cooperation between the baby and the bacteria it needs for normal health. This kind of cooperative interdependence is a hallmark of life. Flowers need a mechanism for pollination; bees need nectar to produce honey. Lichens involve a cooperative relationship between algae and fungi that allows them to live under harsh conditions. Cleaner wrasse fish take care of the hygiene of other fish by eating away debris and ectoparasites their “clients” can’t remove themselves. Fungi work to expand the surface area of roots, enhance absorption of nutrients and also supply a means of communication between plants while plants provide them with sugar.[3]

Although there are many examples of predation and suffering in nature, life at its core is the result of cooperation between many different organisms. The science of ecology has revealed little reason to expect that any organism can survive in the absence of other organisms. Life on Earth at this time exists as robust and cooperative relationships among organisms. These relationships appear essential, elegantly balanced and mutually beneficial leaving little reason to expect that a single first cell could survive and proliferate to produce the robust interdependence we observe. In other words, life looks like a system that must be first established before it can propagate, the kind of thing that genius might design, not something we would expect to see from unguided self-assembly.

Normal science, unencumbered by arbitrary materialistic assumptions about the nature of reality, gives little reason to expect that even the most basic cells originated independent of intelligent guidance. The origin of intelligent life that is self-aware and conscious of its place in the world is another question about life layered on top of the question of living cells, or even complex multi-celled organisms such as plants. The bottom line is that no matter what definition of life one is using, it is a phenomenon well explained as a result of brilliant intelligence that thought it through in advance and put it together as a functioning interdependent system.

Timothy G. Standish

Geoscience Research Institute

[1] For information on the human microbiome, see: http://commonfund.nih.gov/hmp/

[2] See: http://news.sciencemag.org/biology/2013/11/new-rea... http://www.nature.com/nature/journal/vaop/ncurrent... Shokrollah Elahi, James M. Ertelt, Jeremy M. Kinder, Tony T. Jiang, Xuzhe Zhang, Lijun Xin, Vandana Chaturvedi, Beverly S. Strong, Joseph E. Qualls, Kris A. Steinbrecher, Theodosia A. Kalfa, Aimen F. Shaaban & Sing Sing Way. 2013. Immunosuppressive CD71+ erythroid cells compromise neonatal host defence against infection. Nature (2013) doi:10.1038/nature12675. Received 27 March 2013 Accepted 18 September 2013 Published online 06 November 2013

[3] Babikova Z, Gilbert L, Bruce TJA, Birkett M, Caulfield JC, Woodcock C, Pickett JA, Johnson D. 2013. Underground signals carried through common mycelial networks warn neighbouring plants of aphid attack. Ecology Letters 16(7):835-843.