SIMUText Ch. 4 Exam Prep Questions

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SIMUText Ch. 4 Exam Prep Questions What is a population? - ANS - a group of individuals of a single species living in the same general area Why is measuring population growth important? - ANS - 1) s... ome populations could be harmful to other species; invasive species 2) endangered species 3) organisms depend on each other 4) carrying capacity What is unique about the species we measure in geometric growth? - ANS - they breed seasonally, and there is a distinct time the population grows What is the equation for calculating geometric population growth? - ANS - Nt = No * lambda ^ (t) What do the variables represent in the geometric growth equation? - ANS - Nt = total population size No = population size at this generation lambda = finite rate of increase t = number of generations What does a lambda greater or less than 1 signify in the GGE? - ANS - if lambda is greater than 1 the population is increasing while a lambda less than 1 means the population is decreasing What happens if lambda gets larger and larger in GGE? - ANS - the population grows faster and faster What is the equation to find lambda in GGE? - ANS - lambda = Nt+1 / Nt When is the equation for exponential growth used? - ANS - it is used for organisms that are continuous breeders, calculations may have to be repeated every year, hour, or day What does anadromous mean? - ANS - fish breed in the rivers but live in the ocean What is one assumption of lambda in the GGE? - ANS - it assumes that successive generations of a population do not overlap which is not realistic for many species What is r in the exponential growth equation? - ANS - it reflects the contribution each individual makes to the growth of the population at each instant of time What is the equation for exponential growth equation? - ANS - Nt = No * e ^ (rt) How can you find r in the exponential growth equation? - ANS - r = ln (lambda) What does r indicate for the population when it is greater or less than 0? - ANS - if greater than 0, this means that the population is growing and less than 0 means the population is decreasing What is rmax? - ANS - it is when conditions are optimal and is called the intrinsic rate of increase What is the equation using rmax? - ANS - dN/ dt (instantaneous rate of change) = rmax * N What is the sign of the rmax value? - ANS - always positive When using the exponential growth equation, how can you find the exact population? - ANS - We can find the exact population by finding dN/dt and adding the original population value What determines rmax for a species? - ANS - life history characteristics and survivorship Who has a higher rmax, large mammals or bacterium? - ANS - bacterium What are some limitations to a population? - ANS - predators, food, water availability When is unlimited growth possible? - ANS - introduction of an invasive species, when bacteria has unlimited growth, reintroduction of an organism How can you biologically control a species? - ANS - by bringing in diseases to prevent rapid growth, but must be species species specific so it doesn't harm natural species What are some examples of species that grow exponentially? - ANS - pests, exotics, pioneers, and humans What is carrying capacity (K) ? - ANS - the max number of individuals that an environment will sustainably support Is the value for K fixed, and what can it be changed by? - ANS - no, things like climate and drought can influence K What is logistic growth? - ANS - as the rate of increase slows as a population grows, it has reached its carrying capacity What is unique about the species that logistic growth measures? - ANS - they can be for periodic and continuous breeders What is the equation for logistic growth? - ANS - dN/dt = r * N ( 1-N/K ) What are density dependent factors? - ANS - factors that have an impact that change depending on population size in an area What are some examples of density dependent factors? - ANS - food, light, space, disease, predation, and parasitism What are density independent factors? - ANS - factors that have the same size effect on small and large population What are some examples of density independent factors? - ANS - weather events, thunderstorms, hurricanes, pollution, and catastrophic events like fires and floods Why might the birth rate decrease as a population increases? - ANS - because resources may become more limited and competition for those resources increases Why might the death rate increases as populations increase? - ANS - because as competition for resources increases survival of adults and offspring decreases When is there no increasing or decreasing of the population, carrying capacity is reached? - ANS - when there is a low birth rate and a high death rate Who is interested in maintaining populations at equilibrium? - ANS - foresters, game managers, conversation biologists What is meta-population theory? - ANS - a set of subpopulations connected via dispersal What is a source-sink system? - ANS - a collection of patches in which one stable population regularly rescues nearby smaller populations that would otherwise go extinct What is a source? - ANS - a high quality habitat that on average allows the population to increase What is a sink? - ANS - an unfavorable population; very low quality habitat on its own would not be able to support a population Why would an animal go to a sink? - ANS - get pushed out of a source; to escape competition, or find mates How does a meta-population work? - ANS - it contains occupied and unoccupied patches that together sustain the meta-population for much longer than any one patch What is environmental stochasticity? - ANS - the random variability in resources availability, ecological community composition, predator pressure, and weather events which causes fluctuations in the population growth rate What is demographic stochasticity? - ANS - variation in population growth rate due to random differences among individuals in reproduction and survival What is the allee effect? - ANS - if the group is to small, the birth rate drops and death rates increase What are some examples of species that experience the allee effect? - ANS - meerkats, passenger pigeons What is the significance of timed delays, damped oscillations, cycles, and chaos? - ANS - small changes in initial conditions could create larger changes and unpredictable behavior over the long term What is the benefit of emigrants? - ANS - they can rescue or recolonize a patch where deaths are greater than births [Show More]

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