Chapter 10 Flashcards
What is life history?
lifetime pattern of growth, development, and reproduction
What are some trade-offs? (5)
- mode of reproduction
- age of reproduction
- number and size of eggs
- young or seeds produced
- timing of reproduction
What are trade-off constraints?
physiology, energetic, and habitat
What extrinsic factors affect life history?
- physical environment and predators/ competitors
- affects age-specific rates, like mortality
What intrinsic factors affect life history?
phylogeny, development patterns, genetics, and physiology
What are 4 examples of asexual reproduction?
- strawberries spreading by stolons
- paramecium splitting
- hydras produce buds
- aphids emerge from unfertilized eggs (parthenogenesis)
How might asexual species reproduce sexually, and 2 examples?
- environmental changes
- hydras turn sexual during warmer seasons, and go dormant and asexual during winter
- aphids can produce winged females to migrate sexually
What are tradeoffs for asexual reproduction? (3)
- genetic clones
- high population growth
- loss of genetic recombination
What are sexual tradeoffs? (5)
- genetic variability
- only half the genes are passed
- specialized reproductive organs that do not have a direct relationship to survival
- energetically expensive to produce gametes, court, and mate
- females have to use more energy to produce eggs
What are dioecious species?
having a male and a female form
What are hermaphrodites, and what do hermaphroditic plants possess?
- male and female parts on same organism
- perfect flowers
What are simultaneous hermaphrodites, and an examples?
- having both sex parts at the same time
- earthworms
What are sequential hermaphrodites, and what are examples?
- switching sexes during lifcycle
- mollusks, echinoderms, and fish
What are monoecious plants, and what do they have?
- separate male and female flowers on the same plant
- imperfect flowers
What are example of cost of reproduction in terms of increased probability of future survival? (2)
- high cost of parental care and feeding can result in higher mortality rates
- one reproductive event may use so much energy that they may lose body mass and immune function
example of direct relationship between body size and fecundity
early reproduction produces fewer offspring
What does natural selection favor regarding maturity and amount of offspring? (3)
- natural selection favors individuals whose age at maturity results in the greatest number of offsprings produced
- early reproduction when low adult survival
- delayed reproduction when low juvenile survival
What are 2 costs of delaying maturity?
- increased risk of death before reproduction
- death before advantage of increased fecundity is fully realized
What is fecundity?
number of offspring produced per unit of time
What is reproductive effort?
energetic cost of a reproductive event
Examples of reproductive effort? (6)
- gonad development
- movement to spawning area
- competition for mates
- nesting
- parental care
- herbaceous perennials (seasonal) have low expenditure when compared to grains
What is a tradeoff for reproductive effort? (2)
as reproductive effort increases, offspring increases, but offspring survival decreases
as reproductive effort increases, parental survival decreases
When is fitness of parent highest?
fitness of parent is highest at an intermediate reproductive investment- especially for those who reproduce repeatedly
why does larger amount of offsprings means lower investment? (4)
- no parental care
- no energy in seeds
- disturbed, unpredictable environment or open oceans
- reptiles and fish
What is altricial?
young born in a helpless condition and require care
What is precocial?
long incubation or gestation to produced advanced birthed young
What is parental care highly developed in?
social insects
What is iteroparous?
organisms that produce offspring more than once
What is semelparous, an example, and where its found?
- investment of energy in growth, followed by one massive reproductive effort, and then death
- salmon and some bamboos
- small, short-lived, and disturbed habitat
Why might semelparity be fit?
- high adult mortality relative to juvenile mortality
- once mature, it may not survive long
Why might iteroparity be fit?
surviving into maturity is favorable
What does phenotypic variation arise from?
genotypic variation and the environment
What is an example of life history phenotypic plasticity?
age and size at maturity
What is a mating system?
pattern of mating between sexes in a population
What is monogamy, and what is a prevalent in?
long-lasting pair bond
prevalent in birds and rate in mammals
Why is monogamy rare mammals?
males in mammals often contribute nothing, so not fit to form pair bonds
Why is monogamy important in mammals?
cooperation of both parents is needed to raise young
What is polygamy?
two or more mates by one individual
What is polygyny?
individual male pairs with 2 or more females
What is polyandry?
female pairs with 2 or more males
When is polygamy fit?
fit for populations with short sexual periods and for when resources are distributed sparsely
Wbat is promiscuity?
mates with different partners with no pair bonds
What is outcrossing?
plant primary mating system where pollen from one fertilizers another
What is autogamy?
self-fertilization in plants
What factors affect mating system? (4)
- competition
- courtship
- territorial defense
- parental care
What the major energetic expenditure for males?
finding a mate
What is sexual dimorphism?
difference in traits in the same sex
What is intrasexual selection?
- male-to-male competition for mate
- larger or more exaggerated features are selected
What is intersexaul selection?
- differential attractiveness of individuals of one sex to another
- shown through displays
What does female select for intersexual selection?
- female selects mate passed on phenotype
- these traits may be correlated with better health, and genetics
How might a female choose mate?
based on resources, habitat, or territories
What kind of males are selected?
males that can defend and acquire territories are selected
What is fast-slow continuum hypothesis?
selective forces imposed by mortality at different stages of the lifestyle
continuum of high to low adult mortality
What are traits of high mortality? (4)
shorter life cycles, faster development, early maturity, and higher fecundity
What are r-strategists?
per capita rate of growth
What are r-strategists? (9)
- short-lived species
- high reproductive rate
- low population density
- rapid development
- small size
- larger number of offspring with low survival
- minimal parental care
- temporary habitats with limited resources
- good colonizers
What are k-strategists?
carrying capacity
What are traits of k-strategists? (9)
- competitive species with stable populations of long-lived individuals
- slower growth rate
- delayed and repeated reproduction
- larger size
- produce few offspring
- provides stored nutrients for offspring
- mortality stems from density than environment
- specialist
- poor colonizers
What is Grime’s life history of plants?
habitat can be classified by stress and disturbance
What is stress, and examples?
- conditions that restrict growth
- light, water, nutrients, temperature
What is a disturbance and examples?
- destruction of biomass
- herbivory, disease, natural disasters
What is ruderal plants, and traits (2)?
- rapidly colonize disturbed sites
- small and short lived
- can disperse easily
What is competitive plants?
predictable habitat with abundant resources
What are stress-tolerant plants?
limited resources
