Being a resolute hydrophobe who has no more desire to go for a swim than might a kitten in a bag or Luca Brasi in “The Godfather,” I admit I never thought of myself as a large, scaleless fish out of water.

Yet after reading Neil Shubin’s brisk new book, “Your Inner Fish,” and speaking with other researchers who use fish to delve into the history of vertebrates in general and ourselves in particular, I realize that many traits we take pride in, the body parts and behaviors we exalt as hallmarks of our humanity, were really invented by fish.