Transitional fossils provide evidence of how species have changed over time through the process of natural selection. They show intermediate stages in the evolution of organisms and provide a bridge between earlier and later species. These fossils show how traits gradually changed and became more adapted to their environment, which is a key concept in natural selection. They also provide evidence for the gradual evolution of complex structures and show the gradual emergence of entirely new body plans. Overall, transitional fossils provide concrete evidence for the gradual and directional change of species, which supports the theory of natural selection.
