density-dependent habitat selection alters fitness in a clonal hexapod
abstract
density-dependent habitat selection shapes the distribution and abundance of organisms
and thus informs our understanding of the eco-evolutionary process. when habitat choice
is contingent on an individual’s expectation of fitness, and when organisms are free to
occupy the habitat they choose, their occupation of habitat is well described by an ideal
free distribution (ifd). but when individuals are related, habitat selection that maximizes
inclusive fitness (maxn) allows cooperative individuals to supplant the ifd. i tested
this possibility by measuring the fitness accrued through habitat selection by clonal
populations of a common soil hexapod, folsomia candida. i controlled variation
associated with genetics and state-dependence by establishing experimental populations
from a single founding mother and growing them under identical conditions. i varied
habitat quality by manipulating substrate moisture. i allowed f. candida to choose
between habitats and differentiated between ifd and maxn habitat selection by
measuring fitness. surprisingly, habitat-selecting f. candida alter the expectations of
fitness and can thus outcompete otherwise theoretically optimal strategies. my research
demonstrates that density-dependent habitat selection is both an ultimate and proximate
mechanism driving spatial population dynamics.