2.4 Sex and Behaviour Flashcards
Who puts in the greatest investment in producing a child
Females
Parental investment costs and benefits
Investment is costly but increases the probability of production and survival of young
Investment is costly but increases the probability of production and survival of young
Parental investment
R-selected/r strategist species
- smaller
- shorter generation time
- mature more rapidly
- reproduce earlier in their lifetime, often only once
- produce a larger number of small offspring
- ## each offspring receives only a smaller energy input
- smaller
- shorter generation time
- mature more rapidly
- reproduce earlier in their lifetime, often only once
- produce a larger number of small offspring
- each offspring receives only a smaller energy input
- limited parental care
- most offspring will not reach adulthood
- smaller
- shorter generation time
- mature more rapidly
- reproduce earlier in their lifetime, often only once
- produce a larger number of small offspring
- each offspring receives only a smaller energy input
- limited parental care
- most offspring will not reach adulthood
r selected/r strategists
k selected/k strategists
- larger species that live longer
- mature more slowly
- can reprieve many times in their lifetime
- produce relatively few, larger offspring
- high level of parental care
- many offspring have a high probability of surviving to adulthood
- larger species that live longer
- mature more slowly
- can reprieve many times in their lifetime
- produce relatively few, larger offspring
- high level of parental care
- many offspring have a high probability of surviving to adulthood
k selected species
when are r and k strategists selected for
- r selection tends to occur in unstable environments where species has not reached ours reproductive capacity
- k selection occurs in durable environments
- ___ selection tends to occur in unstable environments where species has not reached ours reproductive capacity
- ___ selection occurs in durable environments
r selection, k selection
Costs and benefits of external fertilisation
- very large number of offspring can be produced
- many game urs predated or not fertilised, no our limited care, few offspring survive
- very large number of offspring can be produced
- many game urs predated or not fertilised, no our limited care, few offspring survive
External fertilisation
Costs and benefits of internal fertilisation
- increased chance of successful fertilisation, fewer eggs needed, offspring can be retained internally for protection and/or development, higher offspring survival rate
- mate must be be located, which requires energy expenditure, requires direct transfer of gametes from one partner to another
- increased chance of successful fertilisation, fewer eggs needed, offspring can be retained internally for protection and/or development, higher offspring survival rate
- mate must be be located, which requires energy expenditure, requires direct transfer of gametes from one partner to another
Costs and benefits of internal fertilisation
What are mating systems based on
How many mates an individual has during one breeding season
What is based on many mates an individual has during one breeding season
Mating systems
Breeding systems
- polygamy (including polygyny and polyandry)
- monogamy
- polygamy (including polygyny and polyandry)
- monogamy
Mating systems
Monogamy
Mating of a pair of animals to the exclusion of all others
Mating of a pair of animals to the exclusion of all others
Monogamy
Polygamy
Individuals of one sex have more than one mate
Individuals of one sex have more than one mate
Polygamy
Polygyny
One male mates exclusively with a group of females
One male mates exclusively with a group of females
Polygyny
