This chapter promotes the view that different lineages of living things have independent histories and do not share common ancestry. This idea attacks the core tenet of evolutionary theory--that all living things are genealogically related. The refusal to accept common ancestry is the sine qua non (indispensable idea) of creationism in all of its various guises.
To try to undermine confidence in common ancestry, this chapter trots out some hackneyed creationist claims:
- transitional fossils are rare.
- the major animal phyla appeared abruptly in the Cambrian explosion.
The chapter also misuses the work of scientists who study the tempo and mode of evolution by implying that criticisms of gradual change in evolution undercuts common ancestry.
This chapter also engages in a truly atrocious brand of pedagogy. Rather than teaching students what we do know about fossils, it focuses on what we do not currently know. The dangers of this approach can be seen when we examine the actual history of fossil discoveries, and the steadily shrinking lacunae (gaps) in the fossil record. A student who is made to learn about unfilled gaps in 9th grade is likely to carry a memory of that lesson for the rest of his or her life, long after paleontologists have found fossils which clarify the situation.
Scientific inquiry thrives by identifying gaps in our knowledge, proposing a hypothesis which explains the underlying situation, and then testing that hypothesis with experiments. Fossil hunters do the same, combining their knowledge of geology with evolutionary history to narrow down their search for particular fossils. This approach has revealed details of the evolution of humans, of whales, and of life itself which were unimagined when the authors of this critique were in high school. Had our teachers taught us that science could never fill in the gaps, we might be as incurious as the authors of Explore Evolution seem to be.