- Joined
- Aug 13, 2012
- Messages
- 609
- Points
- 18
Human embryos form a tail! Unlike the vast majority of vertebrates, humans don't have tails (& neither do chimps, bonobos, gorillas, or orangutans, our 4 closest living relatives!), yet we form one in embryonic development, just to have it largely resorbed & fused to form our coccyx. Human embryos also start off with the eyes on the side of the head, like the eyes of adult and embryonic fish; our eyes must migrate toward the front of the face to end up in the human-appropriate location. Human embryos also start off with a very fishlike arrangement of aortae & aortic arches, which then require much remodeling to arrive at an arrangement appropriate for humans. Also, human embryos form fishlike pharyngeal arches, & even pharyngeal slits transiently.




