A simple variant of trait group selection, employing predators as the
mechanism underlying group selection, supports contingent reproductive
suicide as altruism (i.e., behavior lowering personal fitness while
augmenting that of another) without kin assortment. The contingent
suicidal type may either saturate the population or be polymorphic
with a type avoiding suicide, depending on parameters. In addition to
contingent suicide, this randomly assorting morph may also exhibit
continuously expressed ...
A simple variant of trait group selection, employing predators as the
mechanism underlying group selection, supports contingent reproductive
suicide as altruism (i.e., behavior lowering personal fitness while
augmenting that of another) without kin assortment. The contingent
suicidal type may either saturate the population or be polymorphic
with a type avoiding suicide, depending on parameters. In addition to
contingent suicide, this randomly assorting morph may also exhibit
continuously expressed strong altruism (sensu Wilson 1979) usually
thought restricted to kin selection. The model will not, however,
support a sterile worker caste as such, where sterility occurs before
life history events associated with effective altruism; reproductive
suicide must remain fundamentally contingent (facultative sensu West
Eberhard 1987; Myles 1988) under random assortment. The continuously
expressed strong altruism supported by the model may be reinterpreted
as probability of arbitrarily committing reproductive suicide, without
benefit for another; such arbitrary suicide (a "load" on "adaptive"
suicide) is viable only under a more restricted parameter space
relative to the necessarily concomitant adaptive contingent suicide.
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