Maps of variability in cell lineage trees
Fig 4
Permutation symmetry of a tree.
Here the 8 allowed permutations of a tree with 3 generations are shown. These permutations, which involve the swapping of labels starting from the original arrangement in the top left corner, are allowed because they do not change the relationships in the tree. For example, consider the swapping of labels between sisters 101 and 100 (second from left in top row). Despite the swap, those lineal positions still have the same sister and mother. After any of the 8 permutations shown here, every lineal position still has the same mother, sister, cousins, granddaughters etc. In other words, the lineage tree relationships are invariant to this set of permutations.