  The phenomenon of apoptosis observed in cell cultures consists in the fact
that unless cells permanently receive a "Stay alive" signal from their
neighbors, they are bound to die. A natural question is whether manifestations
of this apoptosis paradigm can also be observed in other organizations of
living organisms. In this paper we report results from a two-year long campaign
of experiments on three species of ants and one species of (tephritid) fruit
flies. In these experiments individuals were separated from their colony and
kept in isolation either alone or in groups of 10 individuals. The overall
conclusion is that "singles" have a shorter life expectancy than individuals in
the groups of 10. This observation holds for ants as well as for fruit flies.
The paper also provides compelling evidence of a similar effect in married
versus unmarried (i.e. single, widowed or divorced) people. A natural question
concerns the dynamic of the transition between the two regimes. Observation
suggests an abrupt (rather than smooth) transition and this conclusion seems to
hold for ants, fruit flies and humans as well. We call it a shock transition.
In addition, for red fire ants Solenopsis invicta, it was observed that
individuals in groups of 10 that also comprise one queen, die much faster than
those in similar groups without queens. The paper also examines the
corresponding survivorship curves from the perspective of the standard
classification into 3 types. The survivorship curves of ants (whether single or
in groups of 10) are found to be of type II whereas those of the fruit fly
Bactrocera dorsalis are rather of type III. In this connection it is recalled
that the survivorship curve of the fruit fly Drosophila melanogaster is of type
I, i.e. of same type as for humans.
