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Behavioural Ecology
Sexual conflict
Question | Answer |
---|---|
What is sexual conflict? | When reproductive 'aims' of males and females are different |
Why does it exist? | Divergent Potential Reproductive Rates of males and females Selection then acts in general: - On males to prioritise mate quantity through competition - On females to prioritise mate quality through choice - Different potentials can cause conflict |
Types of conflict: 1. direct conflict | Too many males |
2. genetic conflict | Non-preferred males |
3. indirect conflict | Costs arising from male to male conflict/competition |
4. intragenomic conflict | Two sexes, one genome |
Variation in conflict: Potential Reproductive Rate differences | - Interests more aligned (monogamy) - Interests more divergent (promiscuity) |
Costs of mating: 1. time wasting | (subtracting from time to forage, oviposit, be efficient etc) |
2. predation/abiotic risks | |
3. injury/trauma | |
4. pathogen transmission | |
5. disruption of reproductive pair bonds | (risk of desertion) |
6. costs arising from male:male competition adaptations | |
Costs of paternity: infanticide | 260 mammal species analysed for male infanticide: -119 infanticidal -141 not infanticidal |
Costs of mating | WIDE OPPORTUNITY FOR REPRODUCTIVE COSTS WITHIN ANIMAL MATING PATTERNS (TIMEWASTING, PREDATION, INJURY, DISEASE, DIVORCE, MANIPULATION…) |
Costs of mating | WHEN COSTS OUTWEIGH BENEFITS OF SEXUAL REPRODUCTION & SEXUAL SELECTION = SEXUAL CONFLICT |
Costs of mating | WHAT IS THE EVIDENCE THAT COSTS OUTWEIGH THE BENEFITS, AND CONFLICT EXISTS, AND HOW IS IT RESOLVED….?? |
Females evolving WITHOUT sexual conflict quickly lost their ability to tolerate it | (=must have been costly to maintain?) |
CONFLICT & RESOLUTION: SPECIFIC EXAMPLE | Male-female co-evolution in Callosobruchus maculatus |
CONFLICT & RESOLUTION: SPECIFIC EXAMPLE | Mating causes damage to the female tract Multi-mating causes more damage Multi-mating causes reduced female fitness & shorter lifespan |
Summary | FEMALES AND MALES NEED EACH OTHER FOR SEXUAL REPRODUCTION, BUT THEIR INDIVIDUAL ‘INTERESTS’ CAN BE DIVERGENT DIVERGENCE LEADS TO ADAPTATIONS CAUSING SEXUAL CONFLICT (e.g. MATING BEHAVIOUR, MANIPULATION, COMPETITION TRAITS....) |
Summary | SEXUAL CONFLICT CAUSES BALANCED CO-EVOLUTION, SO CAN BE TRICKY TO SEE / MEASURE BUT CONFLICT COULD CREATE A LOAD ON POPULATIONS WIDER INFLUENCES OF SEXUAL CONLFICT…???? |
CAN SEXUAL CONFLICT INFLUENCE SPECIATION – BIODIVERSITY?? | Could multiple male-female arms races lead to more / faster reproductive isolation?? Diversity in reproductive structures only variant between species in some groups |
Sexual conflict in Sepsis flies: mating compatibility | Increasing sexual conflict = reduced reproductive compatibility between populations = evidence for evolution of reproductive isolation and therefore incipient speciation |