first began observing cell differentiation and succession in the nematode Caenorhabditis elegans. Dr. Brenner chose this organism due to its transparent body, quick reproduction, ease of access, and small size, which made it ideal for following cell lineage under a microscope.

By 1976, Dr. Brenner and his associate, Dr. John Sulston, had identified part of the cell lineage in the developing nervous system of C. elegans. Initial results showed that the