Hyper-parasites drive the parasites to extinction. This results in a
community with a relatively high level of genetic uniformity, and therefore
high genetic relationship between individuals in the community. These are
the conditions that support the evolution of sociality, and social
hyper-parasites soon dominate the community. Social hyper-parasites (Fig. 2)
appear in the 61 instruction size class. For example, 0061acg is social in
the sense that it can only self-replicate when it occurs in aggregations.
When it jumps back to the code for self-examination, it jumps to a template
that occurs at the end rather than the beginning of its genome. If the
creature is flanked by a similar genome, the jump will find the target
template in the tail of the neighbor, and execution will then pass into
the beginning of the active creature's genome. The algorithm will fail unless
a similar genome occurs just before the active creature in memory. Neighboring
creatures cooperate by catching and passing on jumps of the instruction
pointer.
It appears that the selection pressure for the evolution of sociality is that it facilitates size reduction. The social species are 24% smaller than the ancestor. They have achieved this size reduction in part by shrinking their templates from four instructions to three instructions. This means that there are only eight templates available to them, and catching each others jumps allows them to deal with some of the consequences of this limitation as well as to make dual use of some templates.