Darwin's anniversary

This year marks the 200th anniversary of Darwin's birth and the 150th anniversary of the publication of Origin of Species.

Richard Dawkins claimed in 1989 that "it is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid, or insane (or wicked, but I'd rather not consider that)."

I suppose it all depends on what you mean by evolution. If you mean that various species undergo selection of genetic characteristics by their environment which make them more or less likely to reproduce these characteristics in their progeny - in other words the survival of the fittest, then of course this is true. In fact, it is a tautology. In a struggle for existence, those that are fittest to survive will survive.

If, on the other hand, by evolution you mean that life has begun as a matter of chance because of the happenstance of various chemicals mixing leading to the formation of amino acids, then protein, then nucleic acids, then some form of cellular organization, then more complex cellular forms until finally the prolific array of different species that now inhabits the earth, including all those that have become extinct, then anyone who believes that has never examined the evidence critically.

Evolutionary theories probably began with Thales of Miletus who lived between 640 and 546 BC. Darwin's contribution to the debate derived from his observations of the genetic variation of domestic animals and then his observation of natural variation on his time on the Beagle, especially at the Galapagos Islands. The mechanism that he related demonstrated that small variations are potentially present in every species and that environmental niches are indeed available that suit one variation over another. Given physical separation - either natural or produced by man - then it is possible to produce extreme variations within a species - a Toy Poodle or a Great Dane, for example, though there are limits to that variation and no-one has yet produced a tiger from a tortoise or a rabbit from a greyhound.

Darwin was a man of his time and he had no clear understanding of the mechanism eg this variation. This had to wait for Mendel's genetic experiments with peas, and even that idea had no physical equivalent until Crick and Watson fathomed out the DNA code.

Modern neo-Darwinism postulates a molecular model of random mutations that are selected for by the same 'survival of the fittest' tautology that Darwin hit upon. However, as we know, although mutations occur and are particularly useful for developing the immune response in the lymph node, elsewhere they are usually deleterious and are the chief mechanism of cancer. To suggest that they are the driving force of evolution envisions a highly improbable landscape.

Francis Crick himself (although no creationist) puts the problem clearly in his 1981 book Life Itself, Its Origin and Nature:

To produce this miracle of molecular construction all the cell need to is to string together the amino acids (which make up the polypeptide chain) in the correct order... Here we need only ask, how many possible proteins are there? If a particular amino acid sequence was selected by chance, how rare an event would that be? This is an easy exercise in combinatorials. Suppose the chain is about 200 amino acids long; this is if anything rather less than the average length of proteins of all types. Since we have just 20 possibilities at each place, the number of possibilities is 20 multiplied by itself some two hundred times. This is conveniently written as 20 to the power of 200, that is a one followed by 260 zeros!

The number is quite beyond our everyday comprehension. For comparison, consider the number of fundamental particles (atoms, speaking loosely) in the entire visible universe, not just in our own galaxy with its 100,000,000,000 stars, but in all the billions of galaxies out to the limits of observable space. This number, which estimated to be 10 to the power of 80 is quite paltry by comparison to 10 to the power of 260. Moreover, we have only considered a polypeptide chain of rather modest length. Had we considered longer ones as well, the figure would have been even more immense.

Even a simple bacterial cell comprises not just one protein, but a whole host of proteins that interact together in complex union.

Put simply, there are not enough molecules in the whole universe for even a simple protein to have evolved by chance.

Brick one in the wall of doubt.