Abstract
‘Vertebrates’ explains the developmental stages of vertebrates from embryos, including the development of the antero-posterior and dorso-ventral axes that define the left and right sides of the animal. The processes of cell division; the creation of a blastula or epiblast; gastrulation; and the formation of the neural tube, which is the early embryonic precursor of the central nervous system, are discussed. Vertebrates are bilaterally symmetric about the midline of the body for many structures, such as eyes, ears, and limbs, but most internal organs are asymmetric. The development of this left–right handedness and the Hox genes that define positional identity along the antero-posterior axis are described.
