Fission

It has already been said that all of the cells comprising a multicellular organism are restricted to being located in such a position that they are in contact with (i.e. in an adjacent grid position to) at least one other cell in the organism. However, as individual cells within a multicellular organism can die at different times (in the ways described in Section 4.3.5), it is possible to get a situation where a collection of cells that was once connected as a multicellular organism breaks into two or more unconnected groups of cells because of the death of one of more cells in the middle of the structure (see Figure 4.4). If such a situation arises, the separate sub-groups of cells each now become separate organisms in their own right. Cell division and organism fission are therefore two distinct ways in which a new organism may be created.

  

Figure 4.4: An Example of Organism Fission.