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high-strain pollen foragers are heavier than those of low-strain pollen
foragers.
4.4.2 Rare- Genotype Specialists
h e rare-genotype hypothesis of Stefan Fuchs and Robin Moritz pro-
poses that task specialization has costs associated with it if too many
individuals perform the same tasks. Colonies benei t by having a distri-
bution of specialists in which specialists for any given task are rare.
h ere could be merit in this hypothesis when one considers that some
tasks probably do have negative ef ects on colony i tness if too many
individuals perform them. In that case, we would expect that frequency-
dependent selection could maintain genetic variation in the popula-
tion. With frequency-dependent selection, an allele for a trait is favored
by selection when it is rare but is detrimental when it is too common,
similar to individual sex alleles in honey bees. One example might be
the hygienic behavior discussed in Section 4.3.2. Hygienic behavior is a
recessive trait (a bee must be homozygous for the genes that af ect the
behavior) and remains at relatively low frequencies in populations even
though there is a clear advantage with respect to reducing parasite and
pathogen loads. Why doesn't it increase in frequency? Perhaps there is
a cost, as well as a benei t.
Chewing combs and removing wax from the nest are associated with
hygienic behavior. Chewing combs can be important for removing
combs that are contaminated or have reduced cell sizes because they
are old and have built up many layers of cocoons. But chewing combs
can also become pathological, from the perspective of a colony, if too
many individuals engage in it. Kim Fondrk (personal observations)
raised daughter queens from a select group of queens in our research
apiary at the University of California-Davis and then instrumentally
inseminated them with semen from their own brothers. He put them in
hives in the apiary and let the colonies of inbred bees grow and develop.
He noticed that some of the hives had piles of chewed wax in front of
them. When he opened the hives, he noticed that the bees were chew-
ing down all the wax on the brood combs, down to the midrib of the
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