What could indicate common ancestry in vertebrates?

The presence of similar embryonic development among vertebrates is a strong indicator of common ancestry. During the early stages of development, many vertebrates exhibit comparable structures and stages, such as the presence of pharyngeal pouches or the notochord. These similarities arise because species that share a common ancestor tend to have retained certain developmental pathways.

As embryonic development progresses, species diverge and develop their unique characteristics, but the initial similarities provide crucial evidence of their evolutionary relationships. This phenomenon is often examined in evolutionary biology to understand how different species are related and how they have evolved over time from common ancestors.

In contrast, identical adult forms might suggest close relationships, but convergence could also produce similar appearances in unrelated species. Similarities in habitat do not directly indicate common ancestry since different species can occupy similar environments. Differences in genetic sequences often point to divergence rather than commonality. Thus, the evidence from embryonic development serves as a powerful tool in tracing evolutionary lineages.