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Unformatted text preview: l host, under monogamy
(no sexual selection) or polygamy (sexual selection).
Populations that move into a new environment will adapt
by natural selection Pat Lorch If females discriminate against maladapted males (bad genes), then
sexual and natural selection will be aligned: Sexual Selection • Sexual selection will accelerate adaptation • Rapid development is favoured in novel host. Claudia Fricke After 35 generations of adaptation:
• beetles adapt to novel host (fitness up) Polygamy is
b etter in NEW
h ost Populations with sexual selection will evolve to higher fitness than
those without • adaptation is accelerated with SS Natural Selection Development rate data Monogamy is
b etter in OLD
h ost -Under the "Good Gene Hypothesis": Natural and sexual
s election are working together in the same direction
-Both forces working together will bring about adaptation
Just how harmonious are male/female
interactions? Sexual Conflict -Waterslider and an unnecessary
p icture of its penis that Prof Rowe
f orced us to look at (above) - Harem
( recall what this is) Costs of mating
Most females mate multiply and it is superfluous wrt gaining sperm Costs include:
• time, and energy • STI’s • increased risk of predation •
death -Males seek to increase
t heir mating frequency
-Females bare most of the
c osts and seek to reduce
m ating frequency
-This is the source of much
c onflict bet ween the t wo
s exes Costs of ejaculate transfer
Ejaculates are often only a few percent sperm, the rest is a cocktail of
proteins and peptides (100+ in flies)
These molecules can be detected in the bloodstream (even in humans!)
shortly after mating.
They have large effects on gene regulation, reproduction, behaviour etc.
Potential costs include:
• changes in reproductive allocation • reduced remating • reduced lifetime fecundity (sex peptide) -All of these above things serve to benefit males, they are
n ot good for females
-Females will experience reduced re-mating: they will not
m ate with other males, this reduces sperm competition 3 2/13/2013 -Males and females have different expectations Divergent...
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This document was uploaded on 01/27/2014.
- Winter '14
- Annotated Lecture S