Biology Reference
In-Depth Information
tion is due to chance, and something must have caused it. Observation of
correlated variables is ot en the beginning of unraveling the casual struc-
tures, as is the case for the phenotypic architecture of pollen hoarding.
We have gone beyond building simple correlations. We have looked
at the association of traits in dif erent genetic sources under dif erent
environmental conditions and have conducted controlled experiments
with wild-type bees to build a robust architecture of traits related to the
amount of pollen stored in the comb (Table 5.2; Figure 5.14). We have
called the fundamental individual behavioral components the
pollen-
hoarding syndrome.
When one steps back and looks at the associations
of these traits, a few trends are apparent. First, they are general, not
specii c to artii cially selected dif erences between high- and low-strain
bees or artifacts of the selection program. h ey are also intimately
Sucrose Response
Pdk1 Expression
Foraging Age
Locomotor Activity
Hr46 Expression
Light Response
Tyr Expression
Vitellogenin
Juvenile Hormone
Nectar Load
Pollen Load
Water Load
Nectar Concentration
Associative Learning
Nonassociative learning
Ovarioles
Figure 5.14.
h e phenotypic architecture of the pollen-hoarding syndrome.
Phenotypic traits span levels of biological organization from the genotype to
foraging behavior. Lines connect traits that have been demonstrated to be
signii cantly correlated. Studies were performed on high- and low-strain
workers, as well as wild-type bees. All traits shown here vary between bees of the
high- and low-pollen-hoarding strains. Ovariole and vitellogenin phenotypic
traits are discussed in detail in Chapter 7.
