In the given statement, the correct terms to complete it are "pharyngeal arches" and "developmental."
Here's a breakdown of why these terms are the correct choices:
1. **Pharyngeal arches**: Pharyngeal arches are a series of bony loops in the pharyngeal region of the embryo. In vertebrate embryos, these arches give rise to structures like the jaws, inner ear bones, and throat structures. The presence of pharyngeal arches in embryos of all vertebrates is a shared characteristic that points to a common ancestry among vertebrate species.
2. **Developmental**: The term "developmental" is used in the context of evidence of a common ancestor among vertebrate species. The shared features during the developmental stages of vertebrate embryos, such as the presence of pharyngeal arches, indicate a common evolutionary history among vertebrates.
By selecting "pharyngeal arches" and "developmental" to complete the statement, it highlights the common developmental features that provide evidence for a shared ancestry among all vertebrate species.
