Charles Darwin's theory that evolution was caused by natural selection explains the sequential nature of groups in the fossil record. The idea that earlier, simpler species have been replaced by later, more complex species explains the diversity of fossils. Darwin's theory of evolution A. is a scientific explanation of the fossil record and modern biodiversity and has been tested by many scientists.

B. is a scientific explanation of the fossil record that has not been tested by many scientists.

C. explains how a new species arose separately after the previous species became extinct.

D. explains how the adaptations of a species do not lead to its survival during periods of change.​