Post copulation Sexual selection: Pryke et al 2010 Flashcards
individuals in socially monogamous species may partake in
copulations outside the pair bond -> Extra pair offspring
what allows females to target genes:
participation in extra pair copulations, combined with genetically loaded process of sperm competition
optimal female mate choice is constrained
by number of compatible/high quality mates
EPP gives females an opportunity to gain
greater genetic quality from other males
Goudian Finch background:
- Genetic incompatibility between inbreeding red and black head colour morphs results in high offspring mortality rates
- singled by head colour, Determined by Z-linked gene (F hemizygous, males homo)
individuals demonstrate pre-cop mate presence to
own morph BUT constraints on availability = mixed morphs
method:
F gouldian finches with genetically compatible partners (Same morph) & non presented with EPP opportunity of genetically compatible & non Gc males
which females were likely to engage in EPC
ALL, 77.5%
all successful copulations were preceded by
active female solicitation (orientation of cloaca towards male)
-most females did this
how many male attempted forced copulation
2, not successful
EP males courtship displays
95% of males, initiated rapidly and didn’t discriminate between compatible and non
benefits of EPC to males and females:
- males increase reproductive success with little investment
- F compatible males increases females number of eggs, F bears costs of investment tho
why may females solicit incompatible?
wrong assessment
post cop
birds store sperm in reproductive tract
-only act of 7 of the eggs as 1&2 taken by social partner
extra-pair males gained
dis-proportionate fertilization success, despite females copulating just once
