Test 1 Flashcards
Ecology
The scientific study of the relationships between organisms and the environment
Population
A group of (Interbreeding) individuals found in the same space or area at the same time
Demography
The study of the age structure and growth rate of populations
Density
The number of individuals in relation to the space or volume in which they occur
Distribution
The geographic and ecological range of a population
Dispersion
The spacing of individuals with respect to one another
b
Probability of an individual having offspring during some time interval (Per capita Birth Rate)
d
Probability of individual dying during some time interval (Per Capita Death rate)
bN
The population birth rate during some time interval
dN
The population death rate during some time interval
rN
The population growth rate
Immigration
Number of individuals that join the population per unit of time
Emigration
Number of individuals that leave the population per unit of time
Exponential growth
The growth rate when per capita rate
(r) remains constant
Open population
Any population with immigration and emigration
Closed population
Any population with no immigration or emigration
John Graunt
- Population demography
- London records of birth and death
- Doubling time
The 2 laws of population growth
- Populations have the potential to rapidly grow
- They usually don’t. Population growth has to be regulated so that there is only a brief period where there is rapid growth
Nt=NOert
Population Size
DN/Dt = RN
Population growth rate
DN/Dt= bN-dN = DN/Dt = (b-d)N
(b-d) = R (Intrinsic Growth Rate)
1/N DN/Dt =rn
Per capital or individual rate
Rate of population change per individual (Per capita) is affect by what 4 things ?
- Birth rate
- Death rate
- Immigration
- Emigration
r= (births - deaths) + (immigration - emigration)
r=b-d when immigration is equal to emigration
Ronald Ross
Used linked equations to study malaria
-dH/dt
-dM/dt
Alexander Von Humboldt
- Early catalogers of vegetation