Biology Reference
In-Depth Information
except for yellow stripes on the abdomen. He then sampled adult work-
ers as they emerged from their cells on the comb over the course of the
season. He found that the proportional representation (percentage) of
the cordovan-type workers changed within individual colonies among
samples. He concluded that the spermatozoa were not randomly or
uniformly distributed in the spermatheca and that they must be clump-
ing. However, both types were found in all colonies in every sample
taken.
Several studies led to the decline of the sperm-clumping hypothesis.
Ross Crozier and Dorothea Brückner published a note in the
American
Naturalist
in 1981 pointing out that there was little evidence for sperm
clumping in honey bees and that even Taber's data only suggested
nonrandom l uctuations in sperm use over short time scales. Robert A.
Metcalf and I had also come to that conclusion on the basis of Taber's
results and in 1978 began to look at patterns of sperm use in colonies
with naturally mated queens using allozyme markers. Allozymes are
ge ne tically dif erent forms of enzymes that are easily detectable. h e
technique of isolating and visualizing allozymes was new and proving
to be a great tool in studying and understanding genetic variation in
populations of plants and animals. Metcalf was a pioneer in the use of
these markers, publishing his i rst scientii c paper in the major journal
Nature
while he was an undergraduate at the University of Illinois. He
went on to do his doctorate with Edward O. Wilson at Harvard Univer-
sity, where he worked on a species of social wasps and was the i rst to
directly measure genetic relatedness and test the inclusive-i tness the-
ory of William D. Hamilton. We sampled emerging worker honey bees
from two colonies over the course of 11 weeks and looked at the fre-
quencies of three allozyme markers, the three forms of the enzyme ma-
late dehydrogenase that we could unequivocally assign to fathers (Fig-
ure 3.3). However, we could distinguish only three groups of fathers
that had common markers. Our results were similar to those of Taber:
we found all three paternal allozyme markers in every sample. h ey
l uctuated somewhat from sample to sample, but the sperm were not
clumping together in a way that could signii cantly reduce the number
