Saumon a la Kaitala et Getz, sauce hollandaise

We investigate the interplay of population dynamics and adaptive dynamics v ia the timing of reproduction, in the context of a caricatural discrete-tim e model. We find that semelparity can cause co-existence of different popul ation-dynamical attractors and that resonance of lifespan relative to popul ation-dynamical fluctuations can have a profound effect on invasibility and the resulting evolutionarily stable life-history. Different local attracto rs of the resident population dynamics can have different invasion properti es. Successful invasion in one attractor can be followed by extinction of t he former invader, ultimately leading the resident to the same attractor, b ut phase-shifted, or to another attractor. So a strategy can be 'invasible, yet invincible'. In addition, our analysis emphasizes that, for a fluctuat ing population, one must carefully distinguish between polymorphisms and mi xed strategies.