Chapter 7 Life History Flashcards
An individual organism’s ___ _____ consists of major events related to its ___ _____ ___ and _____
life history
growth, development, reproduction, and survival.
___ _____ ___ vary among individuals & populations and are influenced by natural selection.
Life history traits like Timing, duration, phenology, rate, allocation, allometry, etc. are shaped by _____ ____
Life-history traits
natural selection
Life-history strategy is a _____-____representation.
The life history strategy of a species is the overall pattern in the _____ and ____of life history averaged across all the individuals in the species.
population-level
timing and nature
____ _____ occurs in asexual reproduction and produces ____ _____ ____
Binary fission
genetically identical clones
Sexual reproduction produces ____ _____ ____
genetically variable offspring
The production of equal sized gametes is called _____ . In most multicellular organisms however the two types of gametes are different sizes, a condition called _____ .
isogamy.
anisogamy.
One cost of sexual reproduction: the asexual individual will _____ in number more rapidly, _____ out the sexual individual.
increase
wiping
Because meiosis produces _____ gametes that contain _____ the genetic content of the parent, a _____ reproducing organism can transmit only _____ of its genetic material to each offspring, whereas _____ reproduction allows transmission to the _____ genome.
haploid half
sexually half
asexual entire
recombination and the independent distribution of chromosomes into gametes (during meiosis) can disrupt ____ _____ ____, potentially reducing offspring fitness.
favorable gene combinations
the growth rate of sexuality reproducing populations is ____ _____ ____ of asexually reproducing ones, all else being equal.
only half that
Sex has some clear benefits, including _____ , which promotes _____ _____ and hence may increase the capacity of populations to evolve in response to environmental challenges such as drought or disease.
recombination
genetic variation
Complex life cycle – 2 or more distinct stages that differ in ____ _____ or ____
habitat, physiology, or morphology
Examples of complex life cycles: E.g., Alternation of Generations in plants; E.g., Holometabolous insects: Larval, pupal & adult wasps; E.g., Anadromous & catadromous fishes: Anadromous salmon adults live at sea, but spawn in freshwater; E.g., Metamorphic amphibians: Herbivorous, aquatic tadpole will become carnivorous, terrestrial adult.
Diadromous – _____ (migrate from sea to freshwater to spawn) or _____ (migrate from freshwater to sea to spawn) life cycle.
anadromous or catadromous
Separate life history stages can evolve _____ _____ .
somewhat independently.
Ex of complex life cycle is that many organisms undergo metamorphosis, an abrupt transition in form from the larval to the juvenile stage that is sometimes accompanied by a change in habitat
Ontogenetic niche shifts Occur _____ in organisms with _____ life cycles, but occur in _____ organisms as well
routinely
complex
other
An allocation tradeoff is just like an ____tradeoff – a given amount of money spent on beer could not then be used to buy broccoli, and vice versa. Whether or not a particular life-history trait is favored by natural selection depends on the ___/____ ___
Trade-offs occur when organisms ___ their limited energy or other resources to one structure or function at the ___ of another. Trade-offs among life history traits are common.
economic
benefit/cost ratio.
allocate
expense
Many organisms show a trade-off between their ____ in each individual offspring and the ____ of offspring they produce. Investment in offspring includes energy, resources, time, and the loss of chances to engage in alternative actives such as foraging.
In many cases organisms that make a ____ investment in each offspring produce ____ numbers if large offspring, while organisms that make a ____ investment in each offspring produces ____ numbers of small offspring.
investment
number
large
small
small
large
Parental investment can also affect offspring quality as when ____ investment per offspring ____the risk of offspring mortality.
reduced
increases
Parental care is rare. In organisms that don’t provide parental care, resources invested in propagules (eggs, spores, seeds) are the main measure of reproductive investment.
The ____ of the propagule is the ____ ____ of parental investment, and propagule ____is traded off against the ____of propagules produced in a reproductive bout.
size
primary measure
size
number
Allocation trade offs are more defined by a ____ ____ .
That line is a constraint ceiling above which no one could ever fall because we’re starting with a finite resource. You can go below the line.
constraint line.
The “____” that is optimal under one set of circumstances is unlikely to be best suited to another set.
design
Semelparous vs. Iteroparous (Monocarpic vs. Polycarpic) Often entails a reproduction – ___ ____
____species reproduce only once in a lifetime, whereas ____species have the capacity for multiple bouts of reproduction.
survival tradeoff
Semelparous
iteroparous
R-selection and k-selection describes two ends of a ___ ____ ___ ____
continuum of reproductive patterns
___- ____ is the “live fast, die young” and favors high and fast developmental rate, rate of maturation, and reproductive rate.
R-selection
___- ____ is the “Slow & steady” and favors longer and larger body size, life span, and parental investment to offspring.
K-selection
K-strategists are similar to ____ and r-strategists are similar to ____ .
Competitive plants are adapted to low stress low disturbance habitats.
Stress tolerant plants are adapted to high stress low disturbance habitats.
Ruderal plants are adapted to low stress high disturbance habitats.
Competitors
Ruderals
“Lack Clutch Size” = clutch size that ____ the number
of ____ that a parent can rear to maturity, given the tradeoff between investment per offspring vs. number of offspring
maximizes
offspring
