Biology Reference
In-Depth Information
4
h e Evolution of Polyandry
Honey bee queens mate with a large number of males—they are poly-
androus. Estimates of the number of mates range up to more than 20.
Understanding polyandry is important for understanding the mecha-
nisms of social behavior (the spirit of the hive) because there are pheno-
typic consequences of genetic variation at the individual and colony
levels. But we also would like to understand its evolution, and it is im-
portant to keep the questions of consequences and evolution separate.
Chapter 3 dealt with the behavioral consequences of within-colony
genetic variation for behavior, some of which is a consequence of poly-
andry, some a consequence of genetic recombination. In this chapter, I
discuss its evolution. I begin by introducing hypotheses that have been
proposed and what I think are the necessary components and require-
ments of a sui cient evolutionary model. I then present in detail one
model that I think fuli lls the requirements, the sex-determination hy-
pothesis, followed by a discussion and evaluation of other hypotheses
that provide plausible explanations.
4.1 Why Do Queens Mate with So Many Males?
h e question of the evolution of polyandry was coincidental with the
realization that queen honey bees mate with many males and mix their
sperm. Until then it had been generally accepted that the queen mated
so many times because she needed all those sperm, up to many times
77
