Evolutionary generalities

Figure 1.30: A T2 lattice is subject to erosion on both edges. Depending on how the erosion is initiated, and the format of the surrounding environment, periodic interfaces will develop. Here, a T2 lattice decays asymmetrically. To the left, a T1 lattice forms, separated from T2 by a reasonably thin interface; in its turn the T1 merges into the ether. On the right the decay takes longer, is more complicated, and establishes itself after a transient which is still not finished in a hundred generations or two. It remains to be seen whether the D which has formed will be stable under the repeated A salvoes, whose existence has stabilized towards the bottom of the figure.

Figure 1.31: A more complicated decay example in which T18's recur periodically in the decay of the left margin of a ``shift right seven in six generations'' lattice. The T18's themselves shift right fourteen every thirty six generations, which is commensurable with the decaying lattice. They are just barely shadowed by the left spine of the T18 and the T3 (which could be bigger, but can't be smaller, which is all that matters) sitting immediately under it.