88 Self and the Phenomenon of Life
b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”consisting of a stalk and spores. The mature spores are released and,
when conditions are favorable, germinate into free-living, single-cell
amoebas to start the life cycle again. The entire process takes about
thirty hours. This clever trick for self-preservation is not observed in
other unicellular eukaryotes.^13
4.2.4 Self-optimization of the slime mold Physarum
polycephalum
The Physarum is a cell with multiple nuclei. In the growing phase, the
cell increases in size and the nuclei multiply, but the cell does not divide.
All the nuclei are suspended in a contiguous sheet of cytoplasm that cov-
ers an area like a pancake. When nutrients are limited, the cell forms an
Fig. 4.3. Aggregation of the slime mold Dictyostelium discoideum. The top part
shows the free-living, individual cells. The left and lower parts show the grouping of the
cells into a moving slug when food supply is low. The right part depicts the formation of
a fruiting body whereby the spores germinate into single cells. [Wikimedia Commons.]