|The Fossil Record|
The fossil record is one of the most common evidences given for evolution. It is named as such in the National Curriculum for Key Stage 4 Science and so features in most syllabuses and textbooks at this level and above.
But there are several facts about the fossil record which do not fit well with Darwin’s theory of evolution – facts which evolutionary biologists need to explain away rather than use as evidence for their theory. Charles Darwin was very aware of this and devoted a whole chapter of The Origin of Species to the subject.
The key problem is this: Darwin’s theory relies on minute changes in organisms which slowly accumulate, gradually changing the organism until it eventually becomes a new species. If this is correct, then the fossil record should contain many fossils with forms intermediate between different species. This is not what the fossil record shows. As Darwin put it:
Geology assuredly does not reveal any such finely-graduated organic chain; and this, perhaps, is the most obvious and serious objection which can be urged against the theory. (The Origin of Species)
How did Darwin overcome this “obvious and serious objection”? He claimed that the gaps were due to “the extreme imperfection of the geological record” – the fossil record does not in fact give a very good record of the past. One reason for this at the time was the still very limited knowledge of the global fossil record. Darwin expected more intermediate forms to be found as research continued.
But when, 140 years later, Prof. Steve Jones of University College London published an updated version of Darwin’s Origin of Species in 1999, the fossil record still posed the same problem.
The fossil record - in defiance of Darwin's whole idea of gradual change - often makes great leaps from one form to the next. Far from the display of intermediates to be expected from slow advance through natural selection many species appear without warning, persist in fixed form and disappear, leaving no descendants. Geology assuredly does not reveal any finely graduated organic chain, and this is the most obvious and gravest objection which can be urged against the theory of evolution.” (Almost Like a Whale, p. 252)The fossil record is the cause of ongoing debate between evolutionists. On one side geneticists and theoreticians stand for Darwinian “gradualism.” They continue to claim that the lack of intermediate forms is due to the rarity of fossilisation and the imperfection of the fossil record. Thus, the fossil record is something which needs to be explained away – it is not good evidence for Darwinian evolution.
On the other side, those with a more first-hand knowledge of fossils stand for “punctuated equilibrium”: evolution occurs mainly in sudden bursts, with long periods of little change. This explains why intermediate forms are not found in the fossil record. They were around for such relatively short times that the chance of their being fossilised was very low. However, punctuated equilibrium lacks a clear mechanism. How was biological change produced as fast as the fossil record seems to require? This is still debated.
This has led some scientists to say that both evolutionist explanations are wrong, and that all life has not evolved from a common ancestor. Intermediate forms are not found in the fossil record, because they have never existed. In the view of these scientists, unlike evolutionists, the fossil record is a very good source of evidence about past organisms.
Non-evolutionists agree with one another that the fossil record is an accurate portrayal of species in the past, and that intermediate forms never existed. But they disagree on the timing of the fossil record. Some accept the conventional dating of millions of years, and propose that a designer intervened at different moments to modify or create organisms. Others propose that all organisms were created at the beginning, and that the fossil record is due to their deaths at different times in catastrophic events.
So rather than being straightforward evidence for evolution, the fossil record is the subject of a great deal of scientific controversy.
Below are two case studies which illustrate some of the point made above. The first is a fossil species named Archaeopteryx. The second is the sudden appearance of animal groups at the Cambrian explosion.
During Darwin’s lifetime, a fossilised species was discovered which appeared to be intermediate between a bird and a reptile. It had feathers like a bird, but a toothed jaw like a reptile. Named Archaeopteryx it seemed to be just the kind of intermediate form which Darwin’s theory predicted, and was taken as good evidence for evolution. It is mentioned in some British school textbooks today.
However, a general lack of intermediate forms continues to be the overwhelming pattern of the fossil record. Archaeopteryx is a rare exception.
Organisms can be found living today which seem to have forms intermediate between those of others. For example, the duckbilled platypus lays eggs like a reptile but has fur like a mammal. Is this an intermediate form between mammals and reptiles, or does it just reflect the incredible diversity of life?
Recently, fossils of feathered dinosaurs have been discovered, most famously in Liaoning province, China. Some scientists believe that these form an evolutionary link between Archaeopteryx and theropod dinosaurs. This is one of the most contentious issues in current paleobiology.
The Cambrian explosion
About half of the major animal groups appear, fully formed, in the Cambrian strata of rocks, with out any fossilised ancestors. This is how Richard Dawkins, Professor for the Public Understanding of Science at Oxford, describes it:
…the Cambrian strata of rocks, vintage about 600 million years, are the oldest ones in which we find most of the major invertebrate groups. And we find many of them already in an advanced state of evolution, the very first time they appear. It is as thought they were just planted there, without any evolutionary history. Needless to say, this appearance of sudden planting has delighted creationists.” (The Blind Watchmaker, p. 229)How do Richard Dawkins and other evolutionists explain this abrupt appearance? For evolution to be true, there must be a gap here – not just a small gap of one or two intermediate forms – but a truly massive gap of intermediates for at least 19 different phyla. Such a huge imperfection in the fossil record is the only explanation which evolutionists can give.
Why such a gap should occur is not clear. Sometimes it is claimed that the evolutionary ancestors of the Cambrian organisms were small and soft-bodied, and hence hard to fossilise. However, fossilised micro-organisms have been found in Precambrian rocks around the world, and many entirely soft-bodied animals have been found fossilised in Cambrian rocks. There does not seem to be a good reason why such a massive gap should exist.
Non-evolutionists take the fossil record more at face value. Instead of hypothesising a large number of Precambrian animals for which there is no fossil evidence, they take the fossil record to show that the Cambrian animals did not evolve gradually from a common ancestor, and came into being through intelligent design.
Go to our lesson plan on the fossil record
Article corrected 26 October 2006 and 19 March 2007.
Speculations on the chemical origins of life are almost universally covered in school curricula under ‘Evolution’, despite the questionable relevance of the topic for evolution, and its rather uncertain scientific basis.
Moore, A. (2008) Nature 453:31-32