The Accident That Is Life

Charles Darwin once speculated that life on Earth arose in a "warm little pond" of organic chemicals. His hypothesis, stated in a letter to Joseph Dalton Hooker in 1871, was that this pond would needed to have contained all sorts of ammonia and phosphoric salts, lights, heat, and electricity. However, he was not able to test his theory, and so research in this field, known as abiogenesis, progressed slowly.

Then in 1924, Russian biologist Aleksandr Oparin put forward a theory of life on Earth developing within a "primeval soup", through gradual chemical evolution of carbon-based molecules. A further theory by J.B.S. Haldane asserted that ultraviolet light in Earth's primitive atmosphere caused amino acids (the building blocks of life) to concentrate in the oceans. And then in the famous Miller-Urey experiment conducted in 1953, Stanley Miller passed sparks of electricity through a glass chamber filled with water, methane, ammonia and hydrogen. This experiment was intended to re-create the conditions present on primitive Earth, right down to simulating lightning, which was thought to be an important catalyst in early chemical reactions.

Using paper chromatography, Miller was able to detect amino acids and other organic molecules that had formed in a trap connected to the apparatus. The experiment had therefore proved that organic molecules could have spontaneously formed from inorganic precursors, and it made headlines around the world. It seemed that the mystery of the origin of life had been solved. The hypothesis was that organic molecules were formed in the atmosphere after coming into contact with lightning, and were then rained into the ocean, where they combined to make proteins and nucleic acids, which are the basis of all life forms.

However, as with all experiments, objections were raised. Of particular concern was the fact that Harold Urey chose the gases that would be used, after assuming that these gases were present in early Earth's atmosphere. It was argued that by choosing gases that were very chemically active, Urey ensured that something would happen when the gases were placed together and a catalyst was applied. It was also later shown that the atmosphere on primitive Earth did not contain significant amounts of methane or ammonia. Scientists now believe that the atmosphere contained an inert mix of carbon dioxide and nitrogen.

When Miller repeated his experiment in 1983 using these gases in place of methane and ammonia, the resulting brew contained negligible levels of amino acids. Creationists seized upon the failure as evidence of the erroneousness of abiogenesis. Scientists returned to earlier theories to explain the origin of life, such as panspermia. This theory suggests that the origin of life depended heavily on chemicals delivered to Earth by comets and meteorites.

This is difficult to test however, and this is why it is preferable to assume that life originated on Earth rather than elsewhere in the universe. Still, the theory is considered possible, and it has the advantage of extending the available time frame and range of environments for life to develop. Moreover, panspermia does not conflict with the findings of the original Miller/Urey experiment, as many of the organic molecules that were detected by Stanley Miller are known to exist in outer space.

A meteorite that fell in Murchison, Australia in 1969 was shown to be rich in amino acids. Researchers studying the meteorite have identified over 90 amino acids, 19 of which are found on Earth. Since primitive Earth used to be nothing more than an enormous lump of rock, similar in composition to many of the asteroids and comets roaming the galaxy, it would make sense that amino acids were formed at the same time as the Earth, and hung around, in an inactive state. It also follows that many amino acids would have been transferred here by meteoritic infall.

Findings such as these lend credence to the idea that elements not originally present on Earth made their way here from space and were then responsible for the development of life. The early Earth was bombarded heavily by comets, and it is likely that this brought water here, along with a supply of complex organic molecules. Local evidence has also supported this. A meteorite streaked across New Zealand's sky on November 26, 1908. Two pieces of it were retrieved from a small crater at Mokoia, Taranaki. These pieces have been extensively studied, because the meteorite is one of a rare group that contains compounds of carbon and hydrogen.

Even though panspermia is a credible theory, science is continually unearthing new evidence, and recent experiments by Jeffrey Bada seem to have returned the origin of life to Earth. Bada is a chemist at Scripps Institution of Oceanography in La Jolla, California. He discovered that Miller's 1983 experiment, which used carbon dioxide and nitrogen to simulate the early atmosphere, produced chemicals called nitrites, which destroy amino acids as quickly as they form. Bada noted that the early Earth would have had significant amounts of iron and carbonate minerals, which neutralise the effects of nitrites. When Bada added these minerals to the experiment, the resulting liquid was filled with amino acids.

But other researchers are still sceptical of the claim that this finding disproves panspermia. James Ferris, a prebiotic chemist at Rensselaer Polytechnic Institute in New York, agrees that proteins can form after amino acids have been activated by lightning, but he doesn't see how the building blocks of nucleic acids would have developed. His argument seems to suggest that the first cellular organism arose from a combination of earthly amino acids and interplanetary microbes.

At any rate, experiments such as Bada's provide increasing evidence that science, given enough time, will find the answers to the mystery of the origin of life. It is natural to expect that for the time being, the answers will be in a continual state of change. This is the way science works - all "truths" are dependent on examination by others.

For me, the fact that the answer is not set in stone is what makes the contemplation of the origin of life so intriguing. In contrast, the problem with believing that an intelligent designer is responsible for starting life is that you have to maintain this belief, even when evidence comes along that may refute it.

Creationists like to believe that life is so infinitely complex and perfectly ordered that there is no way it could have all come about by chance. They argue that one need only look at the patterns inherent in the natural world to conclude that nature had a designer with intelligence and immense power.

Unfortunately, creationists usually overlook the fact that the creator of something as immensely complex as the universe would also have to have been created. If life cannot be the result of mere chance, it follows that an omnipotent supernatural intelligence would not just spring into existence. Therefore, there must be another designer - a super-designer - with so much power that designing a designer that can design everything is all in a day's work.

And then in order to have a super-designer you would need a super-super-designer. This is where the whole theory falls flat. I'm no closer to an answer about the origins of life than when I first started my philosophical musings.

There seems no reason to assume that the appearance of life on Earth was planned. Just look at atoms and their weird worlds of chaos. Electrons follow random paths and do not seem to be governed by any known rules. Creationists are well aware of this but do not find it convincing. They claim that the chance occurrence of the right combination of atoms needed to form even the simplest of living organisms is so remote that life must be the result of intelligent planning.

Creationists who make statements such as the above do not truly understand chemical evolution. The complex compounds that make life possible are not the result of a sudden combination of atoms; rather, they are the result of many intermediate steps and synthesising processes. Life started off in the most basic way possible, then succeeded in pushing forward. Life may indeed be an extraordinarily unusual occurrence, but this doesn't mean we should immediately assume conscious design. I quote the argument of W.T. Stace:

A man walking along a street is killed by a tile blown off a roof by the wind. We attribute this to the operation of blind natural laws and forces, without any special design on the part of anyone. Yet the chances against that event happening were almost infinite. The man might have been, at the moment the tile fell, a foot away from the spot on the sidewalk on which the tile fell, or two feet away, or twenty feet away, or a mile away. He might have been at a million other places on the surface of the Earth. Or the tile might have fallen at a million other moments than the moment in which it did fall. Yet in spite of the almost infinite improbability of that happening, we do not find it necessary to suppose that someone threw the tile down from the roof on purpose. We are quite satisfied to attribute the event to the operation of natural forces.

Biologists have accumulated a vast body of knowledge about the natural world, and this was achieved by looking no further than nature itself for explanations. Yet even with the quantity of information available, the origin of life is a topic in which the creationist view prevails. This is because it is one of the few areas for which science does not have a conclusive answer. However, having unanswered questions does not mean we should create a "god of the gaps".

Gods were responsible for disease until we found bacteria and viruses. Until recently, mental illness was thought to be caused by demonic possession. Now we know there are biochemical causes. It is only natural that God's sphere of influence will steadily shrink as we find out more and more about the universe in which we live.

Because there is no way to dust for the fingerprints of an intelligent designer who transcends natural processes, we have to stick with what is observable. Science can only deal with what is observable. In order for us to function as rational human beings, we must stop seeing patterns where there is only randomness and see things as they really are.