Biology Reference
In-Depth Information
5.2 Selective Breeding for Pollen Hoarding
In 1986, I took my i rst faculty position at h e Ohio State University.
Walter Rothenbuhler had just retired, and I was fortunate to be hired as
his successor, an honor for an aspiring behavioral geneticist. Rothen-
buhler was one of the pioneers of behavioral genetics and had taken
Rick Hellmich as a graduate student to work on an artii cial-selection
project to study the heritability of pollen hoarding, the amount of sur-
plus pollen stored by colonies. h ey produced two strains of bees that
dif ered in the amount of pollen they hoarded. h ey estimated the heri-
tability (
h
) of the trait to be 49.5 (see Section 5.2.1 for an explanation of
heritability). h is was a very high heritability for a behavioral trait. h e
main purpose of the project was to breed bees to store more pollen in
order to be more active pollinators and have better colony nutrition.
When I arrived, the strains were being maintained by Nick Calde-
rone, a former master's student of Rothenbuhler's, and Kim Fondrk,
Rothenbuhler's technician. Calderone wanted to get a doctorate and
continue working with the stocks. I was interested in looking at the ef-
fects of selection for a colony-level phenotype on individual behavior.
Calderone took on a doctoral project under my direction. h e results of
his important studies are discussed in Chapter 3.
In 1989, I was of ered a faculty position at the University of California-
Davis, where I had done my doctoral work. I accepted the position and
moved back. Kim Fondrk moved as well and continued to be my tech-
nician for more than 25 years. I was truly fortunate to have him as a
technician and research partner. Before the move, we discussed the fate
of the pollen-hoarding strains of Hellmich and Rothenbuhler. Should
we take them with us or start over? We decided to initiate a new selec-
tion study in California, using the same selection criteria, but this time
to focus on, and document, the ef ects of the selection on the dif erent
levels of biological organization from social phenotype to genes.
5.2.1 Heritability
I think that heritability needs more explanation because it is an im-
portant concept in breeding. Heritability, ot en shown as
h
, is the
