A common argument leveled against the theory of evolution is that scientists have not been able to produce transitional fossils that show the change of one species into another. In this podcast, we address a common misconception about what transitional fossils actually are.

If evolution is true, whales are related to the even-toed hoofed mammals, and there should be transitional fossil forms dating from about 45 to 50 million years ago.

Critics of evolution sometimes portray the theory as an untestable historical conjecture, depicting it as fundamentally different from experimental science in the lab. But the hunt for the earliest tetrapods was an effort to test a hypothesis that had generated a prediction.

Many evolutionary critics have identified the Cambrian Explosion as a stumbling block to the theory of evolution, arguing that the “expected transitions between major invertebrate phyla are absent, and that the suddenness of their appearance in the fossil record demonstrates that evolutionary explanations are not viable.” Keith Miller argues that the Cambrian Explosion is not so problematic as these opponents claim after all.

I am a fan of the blog "Jesus Creed." Recently it published an interesting post about the transition from fins to limbs as evidenced by fossils of an organism trapped in sediment 375 million years ago.

Geologist Keith Miller examines the "Cambrian Explosion", a period of rapid evolutionary diversification approximately 575 million years ago, and whether it poses a challenge to evolutionary theory.

There are two opposite errors which need to be countered about the fossil record: 1) that it is so incomplete as to be of no value in interpreting patterns and trends in the history of life, and 2) that it is so good that we should expect a relatively complete record of the details of evolutionary transitions within all or most lineages.

The “Cambrian Explosion” refers to the appearance in the fossil record of most major animal body plans about 543 million years ago. The new fossils appear in an interval of 20 million years or less. On evolutionary time scales, 20 million years is a rapid burst that appears to be inconsistent with the gradual pace of evolutionary change. However, rapid changes like this appear at other times in the fossil record, often following times of major extinction. The Cambrian Explosion does present a number of interesting and important research questions. It does not, however, challenge the fundamental correctness of the central thesis of evolution.

Fossils provide a unique view into the history of life by showing the forms and features of life in the past. Fossils tell us how species have changed across long periods of the Earth’s history. For instance, in 1998, scientists found a fossil showing an animal at the transition from sea creature to land creature. This tetrapod had a hand-like fin, confirming a prediction of evolutionary biology. Though the fossil record does not include every plant and animal that ever lived, it provides substantial evidence for the common descent of life via evolution. The fossil record is a remarkable gift for the study of nature.