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A gap in logic
In evolutionary classification schemes organisms are ordered into groups nested within larger and larger groups. All organisms are assumed to be related, and therefore they are all made to fit this pattern, whether the similarities between groups are obvious or obscure. Differences may reduce the degree of similarity, but it is not permitted to infer non- relationship from them. The thinking is: 'Since we can see evolution going on at the lower levels, within species, genera, families and orders, it may be presumed to have gone on at all levels. Ultimately all organisms are related to each other.'
A more questioning approach is required. Before we jump to the conclusion that all organisms are related to each other, we ought to be considering the possibility that they are not, and that evolution has been going on, in at least some cases, only at the lower levels. Here the primary evidence is the fossil record. Does it or does it not show continuous, gradual evolution from a common ancestor?
A gap through five sixths of the fossil record
There are many enigmas in the fossil record, but perhaps the most puzzling is the 'Cambrian Explosion'. In the conventional timescale this is dated to 535-510 Ma (million years ago), some 3,400 Ma after the very oldest rocks on Earth. It is preceded by the ‘Ediacaran’ period, when from 600 Ma marine organisms unlike any known today began to appear, but by 535 Ma they were extinct. Before the Ediacaran, from 3900 Ma to 600 Ma – five-sixths of the geological record – the only known fossils are bacteria, algae, ‘acritarchs’ (other microscopic plankton) and marine fungi. Then, with the Cambrian period, there is an astonishing burst of creativity:
Described recently as 'the most important evolutionary event during the entire history of the Metazoa', the Cambrian explosion established virtually all the major animal body forms that would exist thereafter, including many that were 'weeded out'; and became extinct. Compared with the 30 or so extant phyla, some people estimate that the Cambrian explosion may have generated as many as 100. ... Why, in subsequent periods of great evolutionary activity when countless species, genera, and families arose, have there been no new animal body plans produced, no new phyla?
Roger Lewin, Science 241:291 (1988)
All at once we see sponges, molluscs, brachiopods, jelly fish, crustaceans, trilobites, foraging and tube-dwelling worms, as well as a host of animals that have no analogues in the modern world. None of them are preceded by evolutionary ancestors.
Gaps between fossil groups
The Cambrian Explosion is not a unique phenomenon. Most orders, classes and phyla appear suddenly in the fossil record, without intermediate forms to smoothly link them to their presumed ancestors. Vascular plants appear explosively in the Devonian. Out of the 41 known insect orders, 17 appear in the Carboniferous, another 13 in the following period. Flowering plants appear explosively in the Cretaceous. Nearly all modern mammal orders appear in the succeeding Palaeogene. Nearly all modern bird orders also appear in the Palaeogene.
Thus, while we do not wish to imply that no evolutionary diversification preceded these first appearances, it is clear that gradually increasing complexity is not the overall message. If the theory of evolution were true, fossils would show a pattern which corresponds to the way scientists order organisms into a single ‘tree of life’. For example, we should be able to see lions, leopards and sabre-toothed tigers descending from an ancestor which linked them into one cat family, Felidae. Further back in time, we should see felids and canids (dogs) descending from an ancestor which linked them into the order Carnivora. Carnivora would then link back to a common ancestor with all mammals, and, still further back, mammals would link back to a common ancestor with all animals that have a spinal column. All vertebrates would share a common ancestor with all invertebrate animals, such as worms and shellfish. And all animals, vertebrate and invertebrate, would share a common ancestor with plants, fungi, protists, archaea and bacteria.
These expectations are fulfilled only in the lower levels of classification. Back as far as the Oligocene the cat family shows a fairly continuous branching pattern:
Before that, although the trail becomes more obscure, it seems likely that the early cats descended from a suborder called Feliformia, which included also the ancestors of modern civets, mongooses and hyenas. These take us back to the Eocene. The origin of the Feliformia, however, cannot be traced. According to theory, these should share a common ancestor with dogs, bears and seals, and a little earlier still, with armadillos, ant-eaters, bats and primates. But fossils of such ancestors have not been found. According to Philip Gingerich, an expert on the mammal record:
The beginning of the Eocene is marked... by the sudden appearance of mammals belonging to modern orders. For example, Rodentia, Primates, Chiroptera [bats], primitive true Carnivora [as represented by the extinct miacids], Artiodactyla [cattle, hippopotami], and Perissodactyla [e.g. horses, rhinoceroses] all make their first appearance. … We do not have a fossil record actually documenting the origin of any of these major groups.
From A. Hallam (ed.), Patterns of Evolution as Illustrated by the Fossil Record (1977)
Above the level of order there is no evidence of evolution because there is no fossil evidence at all, for whatever reason.
Niles Eldredge, curator at the American Museum of Natural History, put it this way:
There are all sorts of gaps: absence of gradationally intermediate 'transitional' forms between species, but also between larger groups – between, say, families of carnivores, or the orders of mammals. In fact, the higher up the Linnaean hierarchy you look, the fewer transitional forms there seem to be.
The Monkey Business: A Scientist Looks at Creationism (1982), p 65.
If the fossil record were a branching tree, the levels higher up in the Linnaean hierarchy – classes, phyla, superphyla and kingdoms – would be apparent only towards the end of the fossil record. Close to the beginning we would see only a small branching pattern of closely related forms – effectively just one phylum. Major new groups would arise only as this ‘trunk’ continued to branch and extinctions created gaps that disguised the interconnectedness of all organisms. Instead, classes, phyla, superphyla and kingdoms are already apparent in the Cambrian.
The fossil record as a whole therefore does not show a single branching tree. The pattern is more like the regrowth of an originally planted orchard.
A gap in the geological record
 If the fossil record does not reveal evidence for the Darwinian story, what does it reveal? It certainly does not show animals all being buried and fossilised in a global flood. Among the many difficulties of that idea, we need only repeat that limited evolution can be seen going on throughout Earth history. What we need is an explanation that does justice to both the continuities and the discontinuities.
The key to a solution lies at the very bottom of the Earth's crust. Although 3900 Ma marks the date (in radioisotope time) of the oldest preserved rocks, the origin of the Earth is dated to 4600 Ma. That means that the first 700 million years of Earth's history are missing. Could this correspond to the originally created world, which was so absolutely destroyed that all terrestrial life from that time was 'blotted out'?
We suggest that the sudden successive appearances of animals unrelated to their predecessors represent stages when, in an unstable world recovering from a global cataclysm, surviving populations had simply recovered in sufficient numbers to stand a chance of being fossilised.
To find out more, visit the website Earth History: A New Approach (sponsored by Noah's Ark Zoo Farm).
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