Biology Reference
In-Depth Information
Although high- and low-strain bees demonstrated behavioral plas-
ticity, they were also constrained by their genotypes. Extreme changes
in social environment, such as those that occurred between the high-
and low-strain colonies, did not make the behavior of the high- and
low-strain workers the same. h is can also be demonstrated by testing
bees derived from the high- and low-pollen-hoarding strains, or Euro-
pean (EHB) and Africanized (AHB) honey bees, for their responses to
stimulation with sugar using the proboscis extension response assay
(Figure 2.7). (Honey bees are not native to the New World. h ey were
initially imported from Europe into North and South America, and
today commercial beekeepers in the United States still use European
honey bees. However, honey bees were imported from Africa into Bra-
zil in the mid-1950s and hybridized with the European bees that were
there. h ey subsequently spread across South America, through Central
America and Mexico, and into the southwestern United States. h ey are
known as Africanized honey bees.) If bees are of approximately the
same age and have been maintained under approximately the same
conditions, then high-strain bees are more responsive than low-strain
bees, and AHB are more responsive to sucrose solutions than EHB.
Responses modulate with experience, environment, and age, but the
range over which they change is constrained to a measurable extent by
the genotype of the bee.
3.7 Ge ne tic and Behavioral Dominance
Genetic and behavioral dominance can also occur. Genetic dominance
occurs when one form (allele) of a given gene has more of an ef ect on a
phenotype than another allele when they both occur in an individual—
the individual is heterozygous for the gene. h is is the case for eye
color. If you inherit a blue allele from one parent and a brown allele
from the other, you most likely have brown eyes because the brown al-
lele demonstrates genetic dominance over the blue. Your eye color more
ot en is not an average of the blue and brown phenotypes. In bees, wild-
type black cuticle color
(+
) is dominant over the cordovan
(cd).
A +/cd
heterozygote is black.
