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37 Cards in this Set
- Front
- Back
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The study of populations in relation to their environment is...
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Population ecology
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What are the 3 fundamental characteristics of a population?
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Density, dispersion, and demographics
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The density of a population is...
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The number of individuals per unit of area or volume
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Dispersion in a population is...
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The pattern of spacing among individuals within the boundaries of a population
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What, basically, is the mark and recapture method?
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Marking a few individuals, then releasing them, and using ratios to figure out the population size by capturing a second random group and seeing how many of the 2nd group are already marked.
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What is the most common pattern of dispersion and why?
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"Clumped," because it promotes mating, it is perhaps in an area of suitable environment, and it can help protect against predators.
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Why might there be a "uniform" pattern of dispersion?
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Mostly because of competition, or territorialism among a population
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Give an example of an organism that often represents "random" distribution.
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Dandelions
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The study of the vital statistics of populations and how they change over time is called...
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Demography (birth/death rates, life tables)
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In life tables, a cohort is...
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A group of individuals of the same age
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What is a type I survivorship curve and who does it characterize.
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Low early death rates whereas most death occurs later in life, like humans.
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What is a type II survivorship curve and who does it characterize.
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Constant death rates throughout life, such as in rodents/squirrels.
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What is a type III survivorship curve and who does it characterize.
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Early death as young organisms, then a flattening out curve showing long life, such as in oysters or in organisms that produce much off spring but do not take care of it.
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The traits that affect an organism's schedule of reproduction and survival make up its...
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Life history
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When reproduction begins, how often it occurs, and how many offspring occur at each episode is called an organisms...
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Life history
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What is big-bang reproduction, or selemparity?
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When an organism reproduces one time and has many, many offspring at once (typically occurs when the survival rate of offspring is low)
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What is iteroparity or repeated reproduciton?
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When an organism produces offspring many times in a lifetime (usually when the environment is less deadly, unlike in a desert)
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What is the "trade off" amongst life histories?
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Those that are semelparous cannot also be iteroparous and usually, those that have reproduces die sooner than those who have not
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What is the ultimate population growth equation?
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ΔN/Δt = bN - dN
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What is the equation for the per capita rate of increase?
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r = b - d
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What is the equation for exponential population growth?
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dN/dt = r(max)N
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What is the symbol for carrying capacity (largest number of individuals an environment can hold)?
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K
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IN what model does the per capita rate of increase approach zero as the carrying capacity is reached?
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The logistic population growth model
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When is population growth rate highest?
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When the population is at about half the carrying capacity
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What is the Allee effect?
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The logistical model assumes that adding a person to the population will have a negative affect on resource availability, etc. But some populations can't live alone, like plants that may become subject to wind without any surrounding plants, and this positive population effect is the Allee effect.
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Selection for life history traits that are sensitive to population density is known as...
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K-selection (density-dependent selection)
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Selection for life history traits that maximize reproductive success in uncrowded environments (low densities) is called...
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r-selection
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What is density-independent regulation?
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A factor that causes more death or less birth regardless of how many species there are (density), such as wind that pulls up and kills grass.
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What is density-dependent regulation?
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A factor that causes more death or less birth because the population is so dense, such as less available nutrients because there are so many species.
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Competition for resources, territoriality, disease, predation, and toxic waste accumulation are all examples of...
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Density-dependent population regulation
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How can intrinsic factors be an example of density-dependent population regulation?
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Because, such as in mice, overpopulation or crowding can cause shrinkage of reproductive organs and immune system depression. Thus, more deaths occur and less births occur, so the factor limiting population growth through density inhibition comes from within.
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What study focuses on the complex interactions between biotic and abiotic factors that cause variation in the size of populations?
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Population dynamics
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When a number of local populations are linked, the entire thing is known as a...
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Metapopulation (signifies importance of immigration and emigration)
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What is the demographic transition?
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The movement to low birth rates and low death rates that are almost equivalent
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The number of infant deaths per 1,000 live births is...
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Infant mortality
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The predicted average length of life at birth is...
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Life expectancy at birth
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What measures all the resources needed to sustain a person, city or country?
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An ecological footprint
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