How does Embryology study lead us to understand evolution?
Embryology of different vertebrates provides very strong evidence of different vertebrates showing striking similarities. There is an obvious similarity between embryos of fish, amphibians, reptiles, birds and mammals. A comparison of embryos of vertebrates shows that all have gill slits even though they do not remain later in life (except fish). This indicates a fundamental step which is common to all vertebrates and supports the idea of a common ancestor. Other features which do not exist in the adult form but appear in the embryos include limb buds in dolphins and human tail buds.
This shows that these species share an ancestor, so their developmental processes are similar regardless of other changes which have taken place since their divergence.