Data from: Adaptation in a variable environment: phenotypic plasticity and bet-hedging during egg diapause and hatching in an annual killifish

Two ways in which organisms adapt to variable environments are phenotypic
plasticity and bet-hedging. Theory suggests that bet-hedging is expected
to evolve in unpredictable environments for which reliable cues indicative
of future conditions (or season length) are lacking. Alternatively, if
reliable cues exist indicating future conditions, organisms will be under
selection to produce the most appropriate phenotype – that is, adaptive
phenotypic plasticity. Here we experimentally test which of these modes of
adaptation are at play in killifish that have evolved an annual life
cycle. These fish persist in ephemeral pools that completely dry each
season through the production of eggs that can remain in developmental
arrest, or diapause, buried in the soil, until the following rainy season.
Consistent with diversified bet-hedging (a risk spreading strategy), we
demonstrate that the eggs of the annual killifish Nothobranchius furzeri
exhibit variation at multiple levels - whether or not different stages of
diapause are entered, for how long diapause is entered, and the timing of
hatching - and this variation persists after controlling for both genetic
and environmental sources of variation. However, we show that phenotypic
plasticity is also present in that the proportion of eggs that enter
diapause is influenced by environmental factors (temperature and light
level) that vary seasonally. In nature there is typically a large
parameter zone where environmental cues are somewhat correlated with
seasonality, but not perfectly so, such that it may be advantageous to
have a combination of both bet-hedging and plasticity.