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
Logistic Growth
Growth that occurs when a population’s growth rate (not the population itself) decreases towards zero as the population size approaches at maximum level
Continuous Growth
Population growth that occurs when individuals are constantly reproducing and dying
Discrete Growth
Population growth that occurs when individuals are constrained to specific seasons or times
R0
Multiplicative or per-generation growth rate, generally used for discrete growth.
Density Independent growth
Growth when per capita growth rate is uncorrelated with population density
Density Dependent growth
Growth when the per-capita growth rate is correlated with population density
Genetic Bottleneck
Occurs when a population is greatly reduced in size, limiting the genetic diversity of the species and resulting in a potentially reduced growth rate
Malthus
- Studied population growth in England and the United States
- As population density increases, the quality of conditions decreases because of competition for resources
- Drew a connection between population growth, resources, and behavior
Case study about wolfs
- Genetic Bottleneck
-Population Growth
- Wolves were thought to be extinct in Northern Europe. An unknown pack was discovered and the population started to quickly increase.
- Russian wolf came in and restored the genetic diversity
Heinz vin Foerster
- Determined that the population growth rate was greater than exponential - R is increasing.
- Predicted that the population size would go to infinity 11-13-2026
R and K are affected by ?
Temperature