The image above shows embryos of many different vertebrate species at an early stage of development. Make a list of specific similarities you see between humans and the other species listed. What structures are common in ALL of the embryos above?
How does this information about the embryos and development of vertebrates provide evidence that vertebrates evolved from a common ancestor? Be specific!
Specific similarities between humans and the other vertebrate species include:
1. All embryos have a notochord, a flexible rod-like structure that runs along the dorsal side of the embryo and serves as a primitive spine.
2. All embryos have pharyngeal pouches, which are structures in the throat region that develop into different structures in each species (e.g. gills in fish, tonsils in humans).
3. All embryos have a tail at some point during development, although it may be lost or reduced in some species as development progresses.
These common structures in all vertebrate embryos provide evidence for evolution from a common ancestor because they suggest that all vertebrates share a similar developmental pathway. The presence of these shared structures supports the idea that all vertebrates have evolved from a common ancestor that had these features. The fact that these structures are present in early embryonic stages, before they differentiate into species-specific structures, further supports the idea of a shared evolutionary history among vertebrates.