The Origin of Life

The neglect of the clay theory


Since is is pretty clear that clay minerals form by far the most likely basis for the earliest living systems, historians of science will no-doubt be curious to learn how the theory associated with this idea came to be neglected for some 37 years after it was first explained - despite the eloquent elucidation of the theory - and the lack of any serious objections to it.


Here's my take on the matter:

  1. The theory is not obvious or intuitive - and the originator of the theory - A. G. Cairns-Smith himself found it appropriate to explain its discovery using the metaphor of detective work;

  2. The theory suggests that a whole new bunch of genetic materials were involved - surely Occam's razor would suggest that the first organisms are not so different from the modern ones;

  3. The idea of a genetic takeover can seem far-fetched and unnecessary - and we have no clear example of the process ever occurring;

  4. There is a lot of evidence that seems to point towards carbon chemistry being involved in much of our ancestry.


I'm inclined to think that the last point is the telling one:

Humans sponsor a lot of research into organic chemistry and nucleic acids - since they are themselves constructed out of organic chemistry and nucleic acids. Every once in a while this produces results that may be relevant in some way to life's origin.

Of course this research is valuable - but it creates a continuous association between the question of life's origin and organic chemistry - so that those interested in life's origin tend to get drawn into organic chemistry - and it is organic chemists who get their research in this area funded.

This association is a self-perpetuating one - the more research is done in the area the more discoveries will be made suggesting that RNA, PNA - or whatever - is involved in the origin of life.

Little or no evidence is likely to be found by a similar approach for the clay theory - since the clays were most probably long gone before RNA came onto the scene - and it isn't reasonable to expect to find many scars of such an ancient and archaic genetic material in modern organisms.

The situation is like that of the drunk searching for his key:

A man watched a drunk searching for something on the ground. "What have you lost?" he asked.

"My key," said the drunk.

So the man when down on his knees too, and they both looked for it. After a time, the other man asked, "Where exactly did you drop it?"

"Up the road a bit," the drunk replied.

"Then why aren't you looking for it there?"

The drunk gives him a confused look. "'Cause there's more light here than up the road."

Just as the drunk looks for his key where there is the most light - so the origin researcher will be drawn to where there are the most published studies.

Unfortunately in this case, this will lead them well away from the truth.

Worse, the more studies there are that relate to the link between carbon chemistry and the origin of life, the more the association will sink into people's unconsciousness, and the harder it will be to get funding to explore other theories.


I'm sure eventually the best theory will win out.

No doubt, researchers into the organic origin of life will eventually be seen to be like a large group of people standing around looking up - each straining to see what all the others are looking at.

However, that is certainly not the current situation - and I hate seeing such obviously-incorrect theories in dominant positions.

It seems especially important to topple the notion of an organic origin to life quickly - since theories of the origin of life have a dramatic impact on the sort of experiments which are done in attempting to replicate the abiogenesis event - and the attempt to create living physical systems from scratch may form an important part of mankind's exploration of nanotechnology in the coming century.


Outside Cairns-Smith's work there has been little published about the technical aspects of his theory. Those interested in clay minerals as industrial catalysts simply have not known about or been interested in the origin of life.

Fortunately - as evidence for the intimate association between clay minerals and the origin of life (due to their properties as catalysts) grows - this seems likely to change - at least a little.

Perhaps this phenomenon will lead to some increased interest in Cairns-Smith's theories again.

Will people look again at some electron micrographs, see that there is a lot more high-fidelity information copying going on there than has ever been shown with any plausible prebiotic organic compounds - and reexamine the theory?

I certainly hope so - an intelligent review is now long overdue - and it is frustrating waiting around for other scientists to catch on.


For a page of references to Cairns-Smith's theories see here. |