chapter 53 Flashcards
what is a population?
group of individuals of the same species
what are population dynamics?
study of how populations change over time
what is population density?
number of individuals in a certain area (area=terrestrial, volume=aquatic)
what is immigration?
movement of individuals into a population
what is emigration?
movement of organisms out of a population
immigration and births ___ individuals to a population
add
deaths and emigration ___ individuals from a population
remove
how to measure population density?
measure number and density of individuals, rates of demographic events (immigration, emigration), location of individuals (might not be there all the time),
what is the mark recapture method?
scientists capture, tag, and release a random sample of individuals in a population. scientists capture a second sample of individuals and note how many are marked
what is the equation for population size estimated by mark recapture?
(# tagged in 1st round* # captured in 2nd round)/ how many marked in 2nd round
what are the 3 patterns of dispersion?
clumped, uniform and random
what are patterns of dispersion?
pattern of spacing in a population
describe clumped dispersion
clumped for mating purposes or protection from predators or good resources
describe uniform dispersion
territorial or dont want to share resources
describe random dispersion
no strong attraction/repulsion. least common
what is allelopathy?
has toxin so other plants cant live nearby
what is demography?
vital statistics of a population
what are life tables?
age specific summary of the survival pattern of a population (to see how they survive)
what are cohorts?
an individual in a population of the same species.
what are age-dependent life tables?
tracking demographic events as calendar age
what are stage-dependent life tables?
used for organisms like frogs, insects, etc
what is the first survivorship curve?
low death rate in beginning and middle; humans
what it the second survivorship curve?
constant death rate; beldings ground squirrels
what is the third survivorship curve?
most die in the beginning but those who live get to live for a long ass time; have to make lots of babies; birds
what are reproductive rates?
estimates potential for growth, tracks everything about a litter, only for females
what is the equation per capita rate of increase?
change in population=births+immigrants-deaths-emigrants
when does zero growth happen?
when births+immigrants= deaths-emigrants
when does exponential population growth occur?
under idealized conditions; j shaped curve
what are some idealized conditions?
no predators, more food, more shelter, no disease, resistance to medicine
what is antibiotic resistance?
when a strain resists a type of medicine
what is carrying capacity?
max of number f individuals that an environment can support; varies with the abundance of limiting resources
what is logistic growth?
the per capita rate of increase approaches zero as the population size nears the carrying capacity
what is the allee effect?
individuals may have a more difficult time surviving or reproducing if the population size is too small
what if life history?
the traits that affect its schedule of reproduction and survival
what are the 3 variables of life history?
usual reproduction age, how often they reproduce, amount per pregnancy
what is semelparity?
they nut and then die; aka the big nut
octopuc, salmon, squid, agave
prefers variable environments
what is iteroparity?
repeated pregnancies
prefers stable environment
what is k selection?
density-dependent selection sensitive to population
what is r selection?
density independent selection, maximize population at low density
describe dependent populations
limited resources; predators, competition, territoriality, disease
describe density independent populations
typically abiotic
describe how resource abundance affect population densites among species
less food-> not everyone can eat->competition
describe how size of individuals affect population densities among species
the smaller the individual size-> less energy needed-> increase in population
describe how social organizations affect population densities among species
individuals work together
describe how introduced species affect population densities among species
reach max population b/c the new species dont have predators or pathogens
describe how evolutionary history affect population densities among species
if they usually had a large density then, they will have a large density now
describe how polyploidy and founder effects affect population densities among species
abnormal cell division-> drive genetics into a new species
describe how threatened species affect population densities among species
small population
describe how vicariance affect population densities among species
land barrier causes population to split->speciation
what increases when a population becomes crowded and resource competition increases?
emigration
what are metapopulations?
groups of population linked by emigration; habitat will have good and bad parts
how to maintain zero population growth?
high birth rates and high death rates
low birth rate and low death rates
what is the demographic transition?
the move from the first state to the second state?
whats so bad about the asian tiger mosquito?
transmit dozens of diseases, bites all day long, egg survive in winter
what is acid rain made of?
sulfuric acid and nitric acid
