Abstract
Environmental variability can lead to dispersal: why stay put if it is
better elsewhere? Without clues about local conditions, the optimal
strategy is often to disperse a set fraction of offspring. Many habitats
contain environmentally differing sub-habitats. Is it adaptive for
individuals to sense in which sub-habitat they find themselves, using
environmental clues, and respond plastically by altering the dispersal
rates? This appears to be done by some plants which produce dimorphic
seeds with differential dispersal properties in response to ambient
temperature. Here we develop a mathematical model to show, that in
highly variable environments, not only does sensing promote plasticity
of dispersal morph ratio, but individuals who can sense their
sub-habitat and respond in this way have an adaptive advantage over
those who cannot. With a rise in environmental variability due to
climate change, our understanding of how natural populations persist and
respond to changes has become crucially important.