Final answer:
Scientists examine embryos to explore evolutionary history because embryos can exhibit ancestral features not present in adults. DNA comparisons further reveal genetic relationships, supporting the idea of a shared common ancestor.
Step-by-step explanation:
Scientists examine embryos to investigate the history of life because they provide a unique insight into the evolutionary history of organisms. During early development, embryos can exhibit features that may not be present in the adult form, such as gill slits and tails in vertebrates, indicating a common ancestry. Embryology, the study of organism development, reveals these transient features and suggests a shared lineage among apparently dissimilar species.
Studying DNA and genetic material also plays a crucial role in understanding evolution. The genetic code is shared among all life on Earth, and similarities between the genomes of different species can indicate how closely related they are. This information contributes to the reconstruction of the 'tree of life', which maps the relationships between all living things.
These anatomical and genetic comparisons are supplemented by fossil evidence and advancements in genetics and genomics, allowing scientists to gain a more comprehensive understanding of the biological history and the commonalities that unite various forms of life.