Lab 4: Population Dynamics using Modelling and Simulations Flashcards
What is the BIDE equation?
An equation that models population dynamics, and it states that the size of a population N will change over time depending on four main factors:
Birth (B), Death (D), Immigration (I), and Emigration (E).
If the proportion of individuals that are born and immigrated is greater than the proportion of those that died or emigrated then the population will grow, and vice versa.
What is a type 1 survivorship curve?
Type 1: Have small numbers of offspring, but invest a lot of time and resources into their care therefore they have a high survival rate when young and a low survival rate when old
HUMANS
What is a type 2 survivorship curve?
Have an equal death rate throughout their lives, the number of survivors decreases linearly with time
BIRDS
What is a type 3 survivorship curve?
Produce high numbers of offspring but invest very little in their care/survivability therefore resulting in a high mortality rate when young as well as old
What is a cohort table?
A way to gather information on patterns of survival within a population.
For a cohort life table, you must follow each member of a cohort (group of individuals born at the same time and move throughout life in the same period) for its entire lifetime and track the age at which each individual dies
HARD OR IMPOSSIBLe
What is a static life table?
Another way to gather data on patterns of survival in a population. The age at time of death is recorded for a group of individuals that were born at different times
When does exponential growth occur?
This type of growth occurs when a population size is small or or when there is little to no competition for resources. For this there are two equations, one can be used to calculate rate of population growth and the other can be used to calculate the number of individuals at a given time.
Because there is no limitation on growth, the per capita rate of increase remains constant, and the population size increases with each time interval
What are the two equations assoc with exponential growth and the variables within them?
dN/dt = rN (population growth rate)
r= per capita rate of increase
N= population size
Nt= N0e^rt (# individuals at a given time)
N0= initial # of individuals
r= per capita rate of increase
t= number of time intervals
When does logistic growth happen?
Occurs when there is an upper limit to growth, meaning that there are factors such as resource availability, space, competition that can put a limit on the max size of a population.
These are density dependent factors because their effects depend on the density of the population.
What is the upper limit on logistic growth called?
Carrying capacity, which is the theoretical maximum population size at a particular location. It is the point on the graph where population size flattens out.
There are also two equations for this which can be used to calculate rate of population growth and number of individuals at a certain point in time.
What are the two equations for logistic growth? What are the variables?
dN/dt= rmaxN(1-N/k)
rmax= maximum per capita rate of increase under ideal conditions
Nt= k/ 1+(k/N0 - 1)e^-rmaxt
In the exponential growth model, what happens to population size as r (per capita rate of increase) increases? What about between N0 and population size?
As r increases, the population also gets bigger
LINEAR RELATIONSHIP
Same thing, as N0 increases, population growth increases exponentially
What happens to the time it takes a species to reach its carrying capacity when r increases?
As r increases, the time it takes for a species to reach its carrying capacity decreases (gets there faster)
