Darwin’s theory, if you think of the branching tree, Darwin’s branching tree, the common ancestor down here and the different modern forms of animals up here, you would have one form to begin with and then it would gradually diverge into slightly different forms and more and more different until you get the major differences that we see now. The problem with the Cambrian explosion is that all these major differences appear together at the same time with no fossil evidence that they descended from this common ancestor.
You have a sudden emergence of new biological form and structure and the suddenness of it defies the Darwinian mechanisms. Ability to produce new structure, Darwin believed that his mechanism must act slowly through small gradual incremental changes and as a result he expected to find many transitional intermediate forms from the very simplest organisms to the first animals.
Darwin knew about the Cambrian fossil record and he considered it a serious problem for his theory. He hoped that future fossil collecting would fill in the gaps somewhat and make the theory more plausible but in fact 150 years of continued fossil collecting have made the problem worse. Many more types of animals were involved than Darwin knew about so it’s actually more of an explosion now than Darwin thought it was.
Most biology textbooks however supply little information about the Cambrian explosion, if they even mention it. Boston Globe, the article reported on cutting-edge research by Chinese scientist JY Chen, an internationally respected paleontologist at the Nanjing Institute of paleontology and geology. Chen’s discoveries in the fossil beds in Xinjiang China have rocked the scientific establishment. Located in the province of Yunnan in southern China, Xinjiang has some of the world’s best preserved fossils from the Cambrian era.
Darwinism is maybe only telling a part story for evolution. According to Chen, the fossils he’s discovered turned Darwin’s tree of life upside down. Darwin’s tree is a reverse cone shape. Very unexpectedly our research is convincing us that major phyla is starting down below at the beginning of the Cambrian. The base is wide and gradually narrows. This is almost turned a different way.
I do not believe that animals developed gradually from the bottom up. I think that animals suddenly appeared. Among the Xinjiang animals, we have found 136 different kinds of animals and they represent diversity in the level of phyla and classes. So the sudden appearance makes them very special.
One view that many paleontologists hold is that though the phyla appeared suddenly during the Cambrian explosion, there must have been a long period of evolutionary development before that event.
Some people believe that it was a very rapid origin of these body plans. Other people believe it’s a long gradual build-up to it, which I think is probably right. But there must have been a prehistory in which started at the bottom and worked up to the phylum.
If there was a long history of evolution prior to the Cambrian explosion, there should be an abundance of transitional fossils or perhaps those animals were too small or soft-bodied to be preserved. The Darwinist have known since the 19th century that the Cambrian explosion did not conform to the picture of life that Darwin proposed but one of their explanations for that was something called the artifact hypothesis – the idea that we were simply not sampling the fossil record sufficiently, define the missing transitional intermediates. In the strata just beneath the Cambrian fossil beds, we have a very favorable environment that would have preserved ancestral forms of these animals had they existed. So one of the versions of the artifact hypothesis was the claim that we don’t find these missing Pre-cambrian animals because they were too small and they were soft bodied and what we now find in the Chinese fossils in the beds just beneath the Cambrian explosion are perfectly preserved soft bodied tissues, sponge embryos that are of course soft and microscopic. The new finds in the Chang Jiang formations really completely put to rest the artifact hypothesis. If you can preserve an embryo, you can preserve an animal. And if those animals were there, then we should have found them and they’re not there.
Some defenders of Darwin’s theory argue that random mutations in a special set of genes called Hox genes are responsible for dramatically speeding up the evolutionary process during the Cambrian period. But what’s interesting to me is that these genes are turned on late in development, long after the body plan is established. A fruit fly is already a fruit fly embryo before the Hox genes kick in. The same for a human or a worm or a starfish. So without a mechanism for sudden mutation or record of transitional fossils critics say Darwin’s theory lacks the evidence it needs to account for the remarkable Cambrian explosion.