Biology Reference
In-Depth Information
with many males, genetic variation within colonies increases, but it
decreases among colonies. h is has profound ef ects on how we study
within-colony variation in behavior and the response of populations to
selection on colonies. We need genetic variation within colonies to
study the ef ects of genotypes on behavior, but we need to limit
within-colony genetic variation to breed successfully for traits. Popula-
tions evolve faster with more variation among colonies.
Rick Hellmich and Walter Rothenbuhler controlled mating and
selected bees for the amount of surplus pollen they store (pollen hoard-
ing). I succeeded Rothenbuhler at h e Ohio State University (OSU)
when he retired, and had access to the strains. h e high- pollen- hoarding
strain stored large quantities of pollen, while the low-pollen-hoarding
strain stored less. Nick Calderone reared bees from the OSU high and
low strains together in the same colonies and found that the high-
strain bees foraged earlier in life and were more likely to collect pollen
than were the bees from the low strain. h is was a clear demonstration
of a genetic component of interindividual variation in behavior among
workers within a colony. In this case, however, the bees were not true
sisters but were derived from dif erent artii cially selected populations
and were adopted into colonies.
Gene Robinson and I looked at variation among sisters within colo-
nies. We took advantage of the subfamily composition of honey bee
colonies (Figure 3.3) to study the ef ects of genotype on individual be-
havior. Workers belonging to the same subfamily are more similar in
their genotypes and behavior than are members of dif erent subfami-
lies. We instrumentally inseminated queens with known allozyme
markers for the metabolic enzyme malate dehydrogenase with three
males, each with a distinct marker (Figure 3.3). We could distinguish
the father of all the workers on the basis of the allozyme markers they
inherited. All workers were raised in the same colonies at the same time
and shared the queen as their mother.
We collected bees engaged in collecting nectar, collecting pollen,
guarding the entrance of the nest, removing dead bodies (undertak-
ing), and performing recruitment dances on the surface of a swarm
(scouting). Nectar and pollen foragers were collected at the entrance as
