
What is population and what does it suggest?
 Individuals of the same species in a given area at a given time
 Suggests that space and time are importatnt components

What are 5 attributes of population?
 Size  numbers (rarity, commonness)
 Density  distribution in space (per unit area or volume)
 Change in size over time ( increases/decreases in numbers, range)
 Age structure
 Genetic structure

What is range?
Overall Distributions in space  areal extent of a population or species

Name a species whoes range has expanded?
Zebra mussels

What do transplant experiments test? (2 things)
 wehter a popluation
 1. never disperse there
 2. Can't survive there

What are 3 patterns which populations are distributed within their ranges?
 Clumped or aggregated
 Random
 Evenly or overdispersed

What are the hypotheses for the distribution patterns?
Clumped?
Random?
Even?
 Clumped  resources clumped, social interactions, limited dispersal from parents
 Random  random dispersal, resources
 Even  Resources even, territorial interactions, competition

What is the definition and process of a random distribution?
 An individual has an equal probablitlity of occurring anywhere in an area
 netral interations between individuals and between individuals and local environment

What is the definition and process of regular distribution pattern?
 Individuals are uniformly spaced through the environment
 Antagonistic interactions between individuals or local depletion of resources  territoriality, competition, allelopathy

What is the definition and process for a clumped distribution?
 Individuals live in areas of high local abundance, which are separated by areas of low abundance
 Attraction between individuals or attraction of individuals to a common resource  sociality, resource clumping

How can the distribution of creosote bushes change through time? (3 steps)
 1. Small shrubs establish in high densities and produce a cclumped distribution
 2. Mortality as the shrubs grow reduces clumping and produces a random distribution amond medium shrubs
 3. Competition enforces a regular distribution among large shrubs

How are body size and population size related?
 Because larger body size requires more resources such as food, space, etc. Then we expect that body size and population size should be negatively correlated
 Regressions of body size and population density of plants and animals support this prediction.

Who should know how population numbers change over time?
Economists, planners, farmers, insurance companies, school boards

what is the basis for population growth?
species interactions, evolution, etc.

What processes affect population size? ( 3 things)
 1 Birth rates +
 2. Death rates 
 3. Immigration + , Emigration 

What is r in a population equation?
(birth rate  death rate) or (bd)

What is N in a population equation?
population size

What is the equation for exponential growth?
 dN/dt = rN
 Or the change in numbers (dN) over time (dt) is equal to the growth rate (r) times the number of individuals (N)

What is dN in the equation dN/dt?
Change in number

What is dt in the equation dN/dt?
Change in time

What 3 things prvents continued exponential growth?
 External ( density independent factors)
  weather, huricanes, floods, drought etc.
  catastrophic events
 Self regulation (density dependent factors)
  Resources becoming limiting ( competition)
  Toxic build  up
 Interactions with other species (density dependent factors)
  disease
  predation

What is K in a population equation?
Carrying capacity of environment.

Explain the logistic or S  shaped growth?
 begining of time b>d, r>0
 Middle of time = maximum exponential growth
 end of time Growth rate slows (b + d) or (r =0)

What is another way to put dN/dt
r((K  N) / K)N or (1  N/K)

What is ((K  N) / K)?
a term that slows growth as N approaches K, the carrying capacity or is equivalent to a competition term

What is intraspecific competition?
 The effect of individuals in a population on other individuals ( instantaneous effect )
 Acts to decrease birth rate or increase death rate

What is intraspecific competition in the logistic equation?
((K  N) / N) or (1  N/K)

What shape does a density dependent graph have?
Logistic curve

What shape is a populaaion graph that is density independent?
Exponential growth

What are 5 population features?
 range
 numbers
 density
 age
 genetic structure

Growth of populations in ideal environments can be described with what growth model?
exponential growth model

What growth model shows a population in a limiting environment?
a logistic growth model

