Biology Reference
In-Depth Information
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Darwin's Dilemma and
the Spirit of the Hive
Social insects have fascinated natural historians and philosophers since
Aristotle and continue to fascinate us today with their self-sacrii cing
altruism, complex nest architecture, untiring industry, and division of
labor. h ey presented Charles Darwin with special dii culties for his
l edgling theory of evolution by natural selection. How can sterile castes,
such as worker honey bees, wasps, and ants, evolve when they don't nor-
mally reproduce? h e existence of sterile castes seems to be in direct op-
position to a theory that requires dif erential survival and reproductive
success. Darwin considered an even bigger dii culty to be the observa-
tion that the reproductive individuals in colonies are ot en anatomi-
cally dif erentiated from the sterile workers, showing adaptation of a
sterile caste. However, he considered the biggest dii culty to be the an-
atomical dif erentiation within the worker caste that is dramatically
demonstrated in many species of ants. Darwin waved his arms and in-
voked selection on families as an explanation, an explanation later shown
to be too simplistic.
Social insects provided additional dii culties for Darwin when he
considered the architecture of the honey bee nest (Figure 1.1). Darwin
asked a Cambridge mathematician to study the comb of the bee from
an engineering perspective of strength and economy, concluding,
“
For
the comb of the hive bee, as far as we can see, is absolutely perfect in
economizing labour and wax.
”
How could the wax combs be built with
such precision to maximize the strength of the comb and at the same
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