Evidence for Evolution
First published: 16th May 2009
Stephen Tsui Kwok-wing claims that complexity of life today, gaps in the fossil record and the Cambrian explosion are examples of evidence against the Darwinian theory of evolution ("Creationism row hots up as objectors fight back", 15 May 2009). This is not correct.
Darwin did not predict that representatives of all species must be fossilised, or that we would find the fossils. It is clear that most individuals do not become fossils, so the lack of examples of particular species is unsurprising. Gaps neither prove nor disprove the theory. What is interesting is that, in some cases, we do have sequences of species showing changes, e.g. the development of the horse's leg bones. That is evidence for evolution of some sort.
The apparent Cambrian explosion is also not a problem - "at the same time" actually means a period of 70 or 80 million years, and Darwin did not predict a fixed speed for evolution. Also, they may have been a large variety of complex organisms before the "explosion" that have not fossilised, particularly if they had no hard parts, such as teeth or bones that most often survive. If that was the case, the "explosion" may be the result of the development of hard parts in many different species - the development of teeth in one species would provide a strong evolutionary pressure for its food to develop a defence, maybe hard armour.
Finally, the complexity of life today is exactly what Darwin's theory is best at explaining. I know of no better explanation, if Mr Tsui has a better theory then he can explain it to the world and take his place alongside Darwin, Newton and Einstein as one of the great scientists.