Sex And Behaviour Flashcards
What is parental investment
The comparison of sperm and egg production in relation to number and energy store
Who is there greater investment from
Greater investment by females
What does parental investment result in
Increases the probability of production and survival of young
How can organisms be classified
Can be classified as r-selected (r-strategists) or k-selected (k-strategist) based on the level of parental investment in organisms and no. Of offspring produced
Where does r-selection tend to occur
R-selection tends to occur in unstable environments where the species has not reached its reproductive capacity
Where does k-selected tend to occur
K-selected tends to occur in stable environments
What are the costs of internal fertilisation
It involves energy demanding pursuit of a mate and direct transfer of gametes from one partner to another
What are the benefits of internal fertilisation
- Increased chance of fertilisation
- Fewer eggs are needed
- offspring are retained internally for protection
- There is a higher survival rate among offspring
What are the costs of external fertilisation
- many gametes predated or not fertilised
- No or limited parental care
- few offspring produced
What are the benefits of external fertilisation
-ensures a large no. Of offspring produced
How are mating systems based on
Mating systems are based on how many mates an individual has during one breeding season
What are the ranges of mating systems
Range from polygamy (many) (polygyny and polyandry) to monogamy (one)
What do animals have in regards to mating
Many animals have mate-selection courtship rituals
What can successful courtship be a result of (birds and fish)
Successful courtship behaviour in birds and fish can be a result of species-specific sign stimuli and fixed action pattern responses
What does sexual selection select for
Sexual selection selects for characteristics that have little survival benefit for the individual but increases their chances of mating
