Biology Reference
In-Depth Information
Table 5.2
Association of traits in the pollen-hoarding syndrome
Wild- type
commercial EHBs
Population
comparisons
Selected strains
Trait
High strain
Low strain
WT pollen
WT nectar
AHBs
EHBs
Forage age
−
+
−
+
−
+
Pollen load
weight
+
−
+
−
+
−
Nectar load
weight
−
+
−
+
−
+
Nectar
concentration
−
+
n/a
n/a
−
+
Gustatory
response
+
−
+
−
+
−
Visual response
+
−
+
−
n/t
n/t
Locomotor
activity
+
−
+
−
n/t
n/t
Tac t i le lea r n i ng
+
−
+
−
n /t
n /t
Olfactory
learning
+
−
+
−
n/t
n/t
Note:
Comparisons are shown for workers from the high- and low-pollen-hoarding strains, for
pollen and nectar foragers from commercial colonies that were not selected for pollen hoarding, and
for populations of bees of European (EHB) and African (AHB) descent. + is greater than the
alternative in comparison; − is less than; n/a designates that the comparison was not applicable; n/t
designates that the comparison was not tested.
5.12 A Pollen- Hoarding Syndrome
Over the past 20 or more years, we have built a complex network of phe-
notypic correlations that range from complex social behavior to neuro-
biochemistry and more (see Chapters 6 and 8). However, one of the basic
mantras of biology, taught to every student of statistics, and especially
graduate students from their i rst day, is “Correlation does not imply cau-
sation.” Bill Shipley in his topic
Correlation and Causation in Biology
as-
serts that the opposite is almost always true: correlation does imply cau-
sation, but we just do not know the underlying causal structures. If we
observe a statistically signii cant, systematic relationship between two
things (variables), then we have ruled out the likelihood that this associa-
