1) what is meant by "the tree of life", from what geological time period is tiktalik found?
2) what are the first creatures thought to have had bony skeletons? what is a vertebrate? what is a tetrapod?
3) what are pharyngeal gill slits? do human embryos have them? do they support the relationship of all chordates?
4) what did sir richard owin propose about the ancestry of all chordates, what information did he use to support his proposal, did the information come from fossils, the bones of living vertebrates or both?
5) what does "developmental patterning mean? is developmental patterning conserved "similar" in all vertebrates? compare humans with tiktaalik to support your answer
6) what is meant by the term "vertebrate body plan" what are the main parts of this plan?
7) what is sonic hedgehog and what does it do?