Chase-away versus runaway sexual selection, con't.
In runaway sexual selection, as the male trait becomes more pronounced, and the female attraction to the trait becomes stronger, the fitnesses of both males and females increase. It is a mutualistic coevolution between males and females.
In chase-away sexual selection, as male fitness increases, female fitness decreases, and vice versa. It is an antagonistic coevolution between males and females -- an escalating arms war, such as that between hosts and parasites.
Here are some aids to help you understand and remember the main features of chase-away sexual selection:
The chase-away sexual selection cycle.
(non-graphics version)
The text-only side-by-side comparison of
chase-away and runaway sexual selection.
The chase-away sexual selection slide show.
The runaway sexual selection slide show.
Text-only sequence:
Chase-away selection cycle
Runaway selection cycle
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