Vestigial structures are parts of our bodies that used to have an important job a long time ago but don't work as well now. They help scientists understand how different living things have changed over time.

Here’s why they matter:

1. Clues About Our Ancestors:

   • These structures show that some species are related, even if they look different now.
   • For instance, the human appendix is similar to a part of the digestive system in animals that eat plants.

2. How Species Change:

   • About 70% of all living things have vestigial organs, which show us how they’ve evolved and adapted over many years.

3. Hints About Biology:

   • Vestigial structures help scientists compare different species and figure out how they are related.
   • For example, the pelvic bones in whales don’t help them swim, but they tell us that whales came from land animals a long time ago.

In short, vestigial structures help us learn about the history and changes in evolution.