Final answer:
Extinct forms and transitional features in the fossil record support the theory of evolution by showcasing species' evolution over time through evidence of common ancestry, gradual changes, and patterns of gradualism and punctuated equilibrium.
Step-by-step explanation:
The presence of extinct forms and transitional features in the fossil record supports the pattern component of the theory of evolution by natural selection by demonstrating how species have evolved over time. Extinct forms show that species that once existed are no longer present, which indicates change through time. Transitional features represent the intermediate states between ancestral forms and their descendants, highlighting the gradual changes that occur in the evolution of species. This is evidenced by the fossil of the Archaeopteryx, which has characteristics of both reptiles and birds, suggesting that modern species share a common ancestor.
Furthermore, the fossil record supports theories like gradualism and punctuated equilibrium, showing that evolution can occur both slowly over time or in rapid bursts following long periods of stasis. This is supported by the observation of the fossil record indicating periods of no change followed by sudden changes in species. The varying suture patterns in ammonite shells over time and the way new species emerge in the fossil record at transitions between geological periods are examples of how the fossil record supports these evolutionary theories.