  Population structure has been known to substantially affect evolutionary
dynamics. Networks that promote the spreading of fitter mutants are called
amplifiers of natural selection, and those that suppress the spreading of
fitter mutants are called suppressors. Research in the past two decades has
found various families of amplifiers while suppressors still remain somewhat
elusive. It has also been discovered that most networks are amplifiers under
the birth-death updating combined with uniform initialization, which is a
standard condition assumed widely in the literature. In the present study, we
extend the birth-death processes to temporal (i.e., time-varying) networks. For
the sake of tractability, we restrict ourselves to switching temporal networks,
in which the network structure alternates between two static networks at
constant time intervals. We show that, in a majority of cases, switching
networks are less amplifying than both of the two static networks constituting
the switching networks. Furthermore, most small switching networks are
suppressors, which contrasts to the case of static networks.
