Since they were first recognized as remains of once-living creatures, fossils have captivated our imagination. In his book On the Origin of Species (1859), Charles Darwin devoted two chapters to one of his most vexing concerns—gaps in the fossil record. From Darwin’s day to the present, the completeness of the fossil record (or lack thereof) has remained a centerpiece in the debate over origins. What were Darwin’s concerns, and where do we stand 150 years later?
A View from Origin
“Why then is not every geological formation and every stratum full of such intermediate links? . . . This, perhaps, is the most obvious and gravest objection which can be urged against my theory.” —On the Origin of Species, p. 280
Darwin wrote, “The number of intermediate varieties, which have formerly existed, [must] be truly enormous,”1 yet this record was lacking among fossils. Particularly in later editions, Darwin went to great lengths to address criticisms of his theory, including criticisms about gaps in the fossil record. Darwin tried to explain the gaps in two ways: (1) the geologic record and fossil collections are imperfect, so it will be difficult to discover many transitional forms; and (2) despite so many known gaps at almost every stage of the evolutionary tree, new transitions are sure to be found (or, in rare cases as he argued, had already been found).
Heavily influenced by geologist Charles Lyell, Darwin considered the geologic record to have been built up by gradual processes over millions of years (a view known as uniformitarianism). Nevertheless, Darwin believed that the sedimentary record had many gaps, where long periods of time left no rock record. He based his case for time gaps on various contemporary geological works, as well as his own field experience.
He noted, for example, that some sedimentary strata in England were far thinner than corresponding layers on the European continent, indicating to him that erosion had removed a lot of the rock record.
In the emerging field of paleontology (the study of fossils), Darwin rightly pointed out that the existing fossil collections were paltry compared to what must be a vast trove of fossils yet to be found. With so little of the world investigated, Darwin argued, how could we know what is really out there? Certainly, he thought, more fossils would fill the gaps.
The existence of so many different kinds of sea animals in the lower fossil layers troubled Darwin. He lamented that the lack of fossils below this layer (now known as the Cambrian Explosion) was “inexplicable and may be truly urged as a valid argument” against his theory.
Yet Darwin could not defend his position solely by claiming a small and imperfect record. He needed to address why there seemed to be so little evidence for evolution among the fossils that had already been collected. Here Darwin found himself groping for answers. While Archaeopteryx and other tantalizing new finds had given Darwin some hope, no finely graded lineages, which connected one kind of creature to another, were available.
Worse still, from Darwin’s point of view, the lowest fossil-bearing rocks were filled with vast numbers of complex marine fossils that lacked any hint of their origin or transitional forms from one kind of creature to another. What is now called the “Cambrian Explosion” was wedged into Darwin’s thoughts on gaps. Such a sudden appearance of so many different groups of marine invertebrates, Darwin lamented, was “inexplicable; and may be truly urged as a valid argument” against his theory.
A Modern Assessment
One hundred and fifty years of collecting, recording, and interpreting fossils have provided a wealth of data to assess Darwin’s theory and his predictions about the fossil record. So how did he do?
First, despite all the increased knowledge of the rock record after so much drilling and exploration, many conventional geologists still see the rock record much as Darwin did: a record of long ages with lots of gaps. Many geologists now believe that Lyell’s strict uniformitarianism needs to be replaced by the important role of occasional catastrophes (local floods, tsunamis, etc.) that deposit new rock layers. Despite the occasional gap, though, the geological community generally believes that the geological record is complete enough to make detailed judgments about the pattern of rock layers worldwide.
For several reasons, young-earth creationists believe the rock record preserves a more complete sampling of life. Since most of the fossil-bearing sedimentary rocks were laid down during the year-long catastrophe of Noah’s Flood and during numerous post-Flood catastrophes,2 we expect a far more complete record, not just of the rocks but also of the fossil species that had once lived on earth.
Creationists, then, expect that a vast percentage of the gaps in the fossil record will never be filled, because the organisms to fill those gaps never existed. This seems to be confirmed by the fact that there are only a few recently excavated areas where paleontologists have found new and unusual fossil forms, such as in Asia and South America (but these sources will eventually dry up, too). In contrast, areas where fossils have been collected for a long time, such as in North America and Europe, are now producing far fewer new fossil species than might be expected if evolution were true.
And what of the gaps in the fossil record? First, not all gaps are created equal, so to speak. Gaps between plants and animals, for example, are much more significant than apparent gaps between mammoths and modern elephants (which appear to be varieties within the same created kind). The fossil record, especially the portion deposited by the Flood, is filled with all sorts of creatures, such as trilobites and dinosaurs, that suddenly appear and then disappear, without connection to fossils in lower or higher layers (for more details on the fossil record, see the previous issue of this magazine).
Darwin’s concerns about the Cambrian Explosion (the place low in the rock record where many different major animal groups, or phyla, are first found), for example, are as relevant as ever. In fact, many more major groups of animals have been discovered in the Cambrian than were known in Darwin’s time,3 with little evidence connecting these sea creatures to other forms in the layers below. These large gaps continue to pose strong challenges to evolutionary theory, but they make sense if a catastrophic Flood buried all the world’s sea creatures in a matter of weeks.
What about the supposed lineages in the upper layers of the fossil record within many mammal groups (e.g., horses, camels, and rhinos)? Many creation geologists believe that the world continued to experience major catastrophes in the centuries after the Flood, which would have buried many animals as they spread from the Ark. Fossils of these post-Flood creatures seem to show strong connections with living genera and species.4
Some creationists argue that these fossils are ancestors of the living animals and descendants of the land animals that spread out from the Noah’s Ark.5 Their fossils can give us excellent insight into the range of variation within created kinds, which God preserved on the Ark, and they show us the way that the various kinds were able to diversify in the post-Flood world. Creationists would expect such similarities between species within a created kind.
Secular scientists have identified what they believe are a few candidates for transitions between different kinds of creatures, at least on the surface. Creationists need to honestly and fairly assess what these strange creatures really represent.6 For instance, Archaeopteryx, found shortly after the publication of Origin, continues to excite and mystify researchers. While it is clearly a flying creature (with fully developed flight feathers), other physical traits, such as a long tail and teeth, make it a fascinating mosaic form.7
Likewise, groups of animals that purportedly link reptiles to mammals, or fish to amphibians, are fascinating cases to be studied. Rather than being transitions, they appear to be brushstrokes from God’s creative palette, examples of wonderful designs suited for their unique, pre-Flood environments.8 (For more details, see “Mystifying Mosaics” in the July-Sept. 2008 issue of this magazine.)
Based on a worldview that excluded biblical data and God’s activity in earth history, Darwin was at a loss to explain the absence of so many links in the evolutionary tree. Creationist predictions of widespread gaps between kinds, and elegant continuity within a kind, provide us with a robust view of the record we have, and excite our imagination as we discover more about “the world that then existed [which was] deluged with water and perished” (2 Peter 3:6, ESV).