The Expanded Self: Society as Self 265“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanitydestructive power on buildings. However, in the wild, termites contrib-
ute to ecological balance by recycling wood and other dead plants. In
an open space, when a colony gets big, the subterranean nest can grow
above ground to form mounds of a few meters high, housing several mil-
lion individuals. A colony is made up of nymphs (semi-mature young),
workers, soldiers, and reproductive members of both genders, some-
times including several egg-laying queens, each capable of generating
2,000 eggs a day. The pheromone produced by the primary queen is
believed to be the integrating element of the colony, which is spread by
shared feeding. A queen can live to forty-five years and continue to mate
with the king for life. The workers are the main caste; they digest wood
and feed the other members of the colony. Termites are not predatory.
They use soldiers only to defend against attacks from ants.
12.5 What Causes Insect Eusociality?
Haldane first proposed in 1955 that altruism in social insects has a
genetic basis, that an individual is more likely to sacrifice himself to save
the life of a close relative than an unrelated person simply because of
genetic relatedness, and that altruism is just another way to promote
one’s own DNA. In 1964, Hamilton put this concept into a mathemati-
cal equation: rB>C, where B is the benefit and C the cost of an action,
and r being the relatedness between the giver and receiver.^7 This model
works nicely to explain the evolution of eusociality when considering
the fact that Hymenoptera (to which both bees and ants belong) have a
genetic peculiarity in being “haplodiploids.”^8 Hamilton pointed out that
in these insects, a sterile worker (female) is more related to her siblings
(including the future queen) she cares for than to her own daughter if
she were to reproduce, the relatedness being ¾ and ½, respectively, a
situation not seen in diploid animals, where the values are ½ and ½ (see
Hamilton W. D.’s article for details).^7 Therefore, according to Hamilton,
that the worker bees and ants sacrifice their own reproductive chance in
favor of their siblings actually increases selective fitness for the workers’