Final answer:
Comparative embryology shows that vertebrate embryos share common traits like gill slits and tails, suggesting a shared ancestry. These features often disappear by adulthood, highlighting the importance of embryology in understanding evolutionary relationships and development.
Step-by-step explanation:
Comparative embryology reveals the shared ancestry among different species through the study of early development stages. All vertebrate embryos, including human embryos, display common traits such as gill slits and tails during the early stages of development.
These embryonic similarities provide essential evidence of evolutionary relationships. The presence of such structures, which may not be present in the adult organisms, suggests that mutational changes in embryonic development can lead to significant differences in adult forms, while conservator the embryonic stages.