Early development occurs in a highly organized and orchestrated manner and has long attracted the interest of developmental biologists and embryologists. Cell lineage, or the study of the developmental differentiation of a

For more than 2000 years, embryologists, biologists, and philosophers have studied and detailed the processes that follow fertilization. The fertilized egg proliferates into cells that begin to separate into distinct, identifiable zones that will eventually become adult structures through the process of

Johannes Holtfreter made important discoveries about the properties of the organizer discovered by