How do these phenomena support the theory of evolution?

The pentadactyl limb of most mammals - how evolution works from existing parts and varies them a little at a time to give an organisms the best chance of survival.

The finches of Galapagos island - how species are not static and change radically over time and in different environments.

The embryos of common vertebrates - all vertebrate embryos look similar at the early stages - shows our common ancestor.

The chemical structures of organisms generally - common chemical structure and DNA/RNA strongly suggest a common origin.

The fossil record - shows how species adapt to varying environmental conditions over time. How they are not static and change.

Phenomena such as fossil records, comparative anatomy, molecular biology, and embryology provide evidence for the theory of evolution by demonstrating patterns of common ancestry and gradual change over time.