Exam 2 Lecture 10 Population Dynamics Flashcards
What processes determine current population size (Nt)?
- Number of immigrants/joiners(I)
- Number that emigrate/leave (E)
Two levels of consideration for roles dispersal
- Dispersal affects range expansion and contraction–
- Dispersal affects local population densities
The distribution and abundance of organisms is
dynamic!
Dispersal is variable _____ populations
within
Dispersal abilities within populations have _____
Large amount of variation
________have the potential to influence the population range
Those few individuals that disperse far
_____ influence dispersion patterns within the population
Those individuals that disperse locally
Which species is likely to respond to rapid climate change with shifts in population range?
- A.Africanized honey bees
- B.Eurasian collared doves
- C.White-tailed deerDispersal
A.Africanized honey bees
What processes determine current population size (Nt)?
Number of births (B)•Number of deaths (d)
Life tables are…
a useful tool for inferring population processes
Life tables Provide….
a picture of survival and mortality in populations
Life tables are Used to….
explore population dynamics in context of –birth–death–survivorship–age distribution
Life tables Consist of…
a series of columns which describe aspects of mortality and reproductive output for members of a population according to age.
Life tables are Representative of
a cohort
a cohort
a group of individuals born at the same time
If cohorts are similar over time,
hey can be used to describe a population
If populations are similar over time and space
they can be used to describe a species
Uses of Life tables
–Analyze probabilities of survival of individuals in a population–Determine ages most vulnerable to mortality–Predict population growth–Make inferences about the environmental factors (biotic and abiotic) and intrinsic factors (life history tradeoffs) that influence population distribution and abundance
Methods of Staic Life tables
Static life table
Age distribution
Static life table
Record age at death of individuals within a certain time period
use of Static life table
for mobile and long-lived organisms
Age distribution
Calculate difference in proportion of individuals in succeeding age classes
Assumptions of Age distribution
Assumes differences are due to mortality
Cohort life table
Identify individuals born at same time and keep records from birth to death
use of Cohort life table
Useful for plants and sessile organisms or relatively short-lived species
How to make a life table
- Record the number of individuals alive (Nx) in each age class 2Record the number of deaths in each age class
Age class is determined by
census interval •(x to x +1)
he number of deaths in each age class–Can infer
mortality rate based on proportion surviving•Nx / N0 (N0 is the number of individuals at time = 0)
Dynamic life table
Cohort life table
life table for plants and sessile organisms
Cohort (dynamic) life table
life table for mobile and long-lived organisms
Static life table
Some ___ and most ___ have ____ ___ of young
plants, animals, survivorship
Some ___ and ___ have a more ___ ____ or _____ through live
birds, amphibians, constant survivorship, mortality
What can you infer about his parental care in this cohort?
Parental care is low
Many ___, ____, ____, and ___ have very ___ ______ as juveniles
plants, invertebrates, anphibians, fish, low survivorship
WE can classify populations based on
survivorship patterns (Many populations do not fit these lines exactly, but they provide theoretical limits on population dynamics)
Classifying populations based on survivorship patterns is useful for…
investigating the source of changing population
Which Survivorship curve do U.S. human populations best fit?
Type 1
type 1 survivorship curve
11
type 2 survivorship curve
11
type 3 survivorship curve
11
If human populations shifted to a type II pattern, what could we surmise happened to mortality rates?
B.Mortality may have increased among younger people
Which survivorship curve is most representative of semelparous species?
?
r vs k: survivorship curve
13
Age distribution of a population reflects:
- –History of survival (high and low periods
- )–Periods of successful reproduction
- –Growth potential
–Growth potential
Are older individuals replacing themselves or not?
age distributions give us ____ ____ of population growth
qualitative assessments
Which country will grow faster?
Costa Rica is likely to grow faster than Sweden, because it has more young people to replace those that die
age distributions provide evidence of
reproductive failures or low survival periods
Interpret: 15
There may have been a reproductive failure or a major disturbance 60 years ago
