Seems to have no problem in squeezing history into 6,000 years

IT IS only Craig Roberts (Echo, June 7,) and his fellow creationists that think that the whale’s back stumps are for reproduction purposes. Scientists without a religious axe see them for what they are – atrophied remnants of their common ancestor’s hind limbs.

We know of many transitional species in our own genetic back yard. Homo habilis has the brow ridge of an ape and smaller teeth than an ape, but bigger than modern sapiens.

They also had a bigger brain than apes and an obvious Broca area which implies the beginnings of speech. Homo erectus still had a brow ridge but had a larger Broca area than habilis. They also had a much larger brain and made stone tools.

Craig thinks that the odds of our genetic complexity coming about by chance are astronomically small. This is true if it only came about by single point mutations.

Such a sequence of unrelated points would not produce complexity. However, genomes have reached their current state by other methods as well. Both genes and even proteins can cut and slice themselves and recombine in many ways to achieve complexity.

Transposons are just one way for this to happen and for genomes to expand without additional material being added. For example, 50 per cent of the maize genome is made up of transposons and have brought about great differences between it and related species.

Control elements like ‘promoters’ and ‘enhancers’ determine when, where and to what extent a gene is activated. In contrast to simple organisms in which such controls are on or off, these mechanisms enable a wide range of functions without having to have a correspondingly larger amount of genes.

Histones also contribute much by reacting to the environment and controlling access of proteins to the genome and thereby defining genetic information.

Craig wonders how complexity could come about in 3.5 billion years. He seems to have no problem with squeezing all history into 6,000 years.

At the beginning a creator god made the cosmos and created all the species. In the space of a few millennia this god managed to lose 99 per cent of the species he had so lovingly created, which feat would constitute at least criminal negligence in our legal system. Those species lived out their time span and some specimens got buried under many strata of rock and erosion managed to reveal them again for us to ponder over.

All that in 6,000 years. A bit of a stretch, isn’t it? Keith Harris