I Flashcards
What are the main types of mating systems?
Monogamy, polygyny, polyandry, polygynandry, promiscuity.
What is a correlation?
A relationship between two factors where a change in one corresponds with a change in the other.
What is sexual dimorphism?
Morphological and anatomical differences between the sexes.
What does size difference between sexes indicate about mating systems?
- Males larger than females: polygyny
- Females larger than males: polyandry (sometimes) or egg production.
- Males and females of equal size: Monogamy.
Provide examples of species where males are larger than females.
Elephant seals, gorillas, and shell-dwelling cichlid fish.
What do armor differences between sexes indicate?
Male-only armor correlates with polygyny and competition for mates.
Provide example of species with male-specific armor.
Narwhals, bison, Hercules beetles, African elephants, and caribou.
What is sexual dichromatism?
Differences in colouration between males and females.
What does bright male colouration suggest about mating systems?
Female choice, indicating polygyny or extra-pair copulations.
Name species where males are more brightly coloured than females.
Mandarin duck, peacocks, sage grouse, Mozambique tilapia.
What does bright female colouration indicate?
Possible polyandry
How does resource distribution affect mating systems?
Clumped resources lead to polygyny as males monopolize territories.
How does female distribution affect mating?
Clumped females: polygyny
Dispersed females: monogamy or mild polyandry
Provide examples of species with different female distributions
- Elephant seals (clumped, extreme polygyny)
- harp seals (harp seals (dispersed, mild polygyny or monogamy)
How does parental care correlate with mating systems?
- male care: polyandry
- female care: polygyny
- biparental care: Monogamy
Provide examples of species with different parental care patterns.
- Seahorses (male care, polyandry)
Most mammals (female care, polygyny)
What is sperm competition?
Competition between sperm from different males to fertilize a female’s eggs.
How does testes size correlate with mating systems?
- Large testes: Polygynandry, promiscuity
- small testes: Polygyny, monogamy.
Provide examples of species with different testes sizes based on mating systems.
- Chimpanzees (large testes, polygynandry)
- Gorillas (small testes, polygyny).
- Gibbons (small testes, monogamy).
How do mating systems correlate with brain size in bats?
- Polygynandry: Bigger testes, smaller brains
- Monogamy: smaller testes, bigger brains
What factors help predict mating systems?
Anatomical, morphological, and colouration differences and resource and mate distributions.
