Human beings belong to the phylum Chordata, all members of which have notochords, cartilage rods down the middle of the back, at some time during their life history. Chordata include all vertebrates (mammals, birds, amphibians, reptiles and fish) along with several groups of lesser know marine animals. Details of the evolutionary path of notochords from sea-squirts to jawless fish to bony fish remain obscure.
Whatever the precise path, the backbone that enables us to stand before this exhibit panel speaks to the wonder of evolution. Branches, truncations, mergers — as evolutionary continuity — span nearly 4000 million years.