Sea urchin

Hans Adolf Eduard Driesch

The sea urchin is a relatively simple organism that is useful for studying development. Dreisch showed that by merely shaking two-celled sea urchin embryos, it was possible to separate the cells. Once separated, each cell grew into a complete sea urchin.

This experiment showed that each cell in the early embryo has its own complete set of genetic instructions and can grow into a full organism.