Final answer:
Whale fossils demonstrate evolution by showing the movement of nostril openings, the reduction of hind leg bones, and the overall change from land-dwelling creatures to aquatic whales. These changes trace the adaptations that occurred as whales' ancestors transitioned from land to sea life.
Step-by-step explanation:
Whale fossils provide an excellent example of evolution because they show a progression of anatomical changes that occurred as these mammals adapted from land to aquatic life. This includes changes in nostril placement, where the nostril openings in the skull moved further back towards the top of the head throughout whale evolution. Additionally, there is a clear reduction in the size of hind leg bones, which can be observed in the fossil record, demonstrating the transition from land-based mammals to the fully aquatic whales we see today. Finally, the overall transformation from land-dwelling creatures to modern-day whales is visible in the fossil record, showing a slow and gradual change from more fish-like organisms to the large marine mammals that inhabit the oceans today.
This evidence supports the concept of evolution by tracing the adaptations and modifications that occurred over geological time. For example, vestigial structures like the traces of pelvic bones in whales are remnants from when their ancestors walked on land. Similarly, the evolution of horse anatomy adapting to different environmental pressures over time is another case study often highlighted by paleontologists to illustrate how species change over millions of years. When looking at whale evolution, features such as the transformation of their limb bones suggest descent from a common land-based ancestor, showing the power of evolutionary processes to shape life on Earth.