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Male and Female sexuality
what are female gametes like and what are they restricted by?
- •
- Produce larger, more energetically costly gametes.
- Reproduction
- thought to be limited by resource access
-
Male and Female sexuality
what are male gametes like and what are they limited by
-Produce smaller, less energetically costly gametes
-Reproduction limited by mate access
-
Male and Female sexuality
what are hermaphrodites and what are some of their benefits
- •Hermaphrodites exhibit both male and female function. Conditions that favor
- hermaphroditic populations include:
- Low mobility limiting male:male competition.
- Low overlap in resource demands by male and female structures.
-Sharing of costs for male and female function.
-
Male and female sexuality
describe the variable sexual expression and a benefit of it
- •Variable sexual expression
- (sequential hermaphrodites): sexual expression is a function of
- age and/or circumstance:
- -
- Females and small, sub-dominant males are yellow in color.
-Dominant male of harem has a blue head
-Females can convert to males when dominant male is killed.
-
mate choice
what is sexual selection
- Sexual Selection: Differences in reproductive rates among individuals as a result of
- differences in mating success.
-
mate choice
what are some criteria for choosing a mate
Criteria for choosing a mate
•Size
•Coloration
•Gifts
•Song/dance
-
mate choice
what kind of mates do female favor
- Ryan
- and Keddy-Hector
- (1992) suggest that females prefer
- traits that deviate from the population mean.
-
mate sexual selection in guppies
what kind of guys do guppies want. whats the down side to that.
- •Given a choice, female guppies will
- mate with brightly colored males.
- Brightly colored males attract
- predators
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Social relations
territoriality
- •Territoriality: Defending resources
- against outside competitors
-
Social relations
evolution of society is accompanied by what
•Evolution of sociality is accompanied by:
- Cooperative feeding
- Defense of the social group.
- Restricted reproductive opportunities
-
Social relations
eusociality
- •Eusociality:
- More complex level of sociality.
- - Individuals of more than one generation
- living together.
- Cooperative care of young.
- - Division of individuals into non-reproductive
- and reproductive castes.
-
Kin selection
what is inclusive fitness
- Inclusive
- fitness: increase in group fitness more than
- compensates for the loss of individual fitness.
-
Kin selection
what does inclusive fitness assume
- •Assumes altruism,
- which is a behavior that may reduce the
- fitness of an individual but increase the fitness of other individuals in the
- population.
-
Kin selection
what does altruism improve
- •Improve survival and reproductive rates of
- family members.
-
kin selection
what perks are possible for altruism
- Cooperation may also increase the probability
- of survival and fitness
- of the “helper” or cooperator
-
kin selection
describe hamilton's rule
Rg x B – C > 0
Where:
- Rg = Genetic relatedness of the helper
- and recipient of help,
- B is the reproductive gain of the
- recipient of help
- C = reproductive cost associated
- with helping
- If the reproductive gain of the
- recipient (b) is greater than the cost of
- helping (c), then altruism will increase with
- degree of relatedness
- As soon as c
- becomes equivalent to b,
- altruism declines even in groups of related individuals.
-
territoriality
what is territoriality and when does it happen
- If the reproductive gain of the
- recipient (b) is greater than the cost of
- helping (c), then altruism will increase with
- degree of relatedness
- As soon as c
- becomes equivalent to b,
- altruism declines even in groups of related individuals.
-
territoriality
what does territory defense increase
- Territory defense increases
- resource availability
-
territoriality
when does territorial defense become a waste
- Gill and Wolf (1981) found that
- territorial defense becomes a waste of energy as resource levels increase.
-
Mating systems
monogamy
- Monogamy:
- equal numbers of individual males and females mate
-
Mating systems
polygyny
- Polygyny:
- More individual females mate than individual males
-
Mating systems
polygamy
- More
- individual males mate than individual females
-
Mating systems
when do cooperative systems evolve
- Cooperative
- systems may evolve when poor habitat quality fosters cooperation
-
mating systems
what causes more adults to care for young and acquire food
Reduced food resources require more adults to care for young and acquire food
-
mating systems
what results in grouped reproduction
- •Reduced nesting habitat results in
- grouped reproduction.
-
mating systems
what requires cooperative defense
High predation requires cooperative defense
-
cooperative breeders
what do species that live in groups often do
- Species living in groups often
- cooperate in rearing offspring.
-
cooperative breeders
inherited territory may increase what
- •Inherited territory: May increase
- helper’s probability of future reproduction and recruiting helpers.
-
cooperative breeders
how many female lions are in a group
- •Prides of female lions include 3-6 adults, but may contain as many as
- 18.
-
cooperative breeders
what do female lion groups do together
•Substantial cooperation in hunting, rearing of young.
-
cooperative breeders
what do male lions cooperate in
- Males
- cooperate in territory defense
-
Schooling/flocking/herding
behavior
what can living in a group provide
•Living in a group can provide:
- Cooperative feeding
- Defense in numbers.
- Reproductive opportunities.
-
eusocial species
what are eusocial species like
- Have a social caste system where individuals conduct different activities that are
- vital to the survival of the colony.
-
eusocial species
for ants
•Queen: Reproduction
- •Gardeners: Tending fungus garden
- that feeds the colony.
•Harvesters: Leaf cutting and transport to the nest.
- •Soldiers: Defense of the colony and leaf
- cutting/transport activities.
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