Reproductive Photoresponsiveness: Selection for Genetic Variants
(Peromyscus maniculatus nebrascensis)
In the figure from (Desjardins et al., 1986) is shown the change in the frequency of reproductive photoresponsiveness in P m nebrascensis after two generations FOR (left of P) and AGAINST (right of P) that trait. Approximately 50% of the parental generation (P) were responsive, ie experienced reduced reproductive abilities when exposed to a short photoperiod. Selected photoresponsive mice were bred to produce the F1 generation, and in like manner an F2 generation was produced. Similarly, F1 and F2 generations were produced from parents founded to be non-responsive to photoperiods.
This is a clear demonstration that this population of deer mice manifest selectable genetic variation for photoperiod responsiveness.
Desjardins C, Bronson FH, Blank JL. 1986. Genetic selection for reproductive photoresponsiveness in deer mice. Nature 322:172-173.