Week 3 learning Objectives Flashcards
What are population demographics?
The size, age structure, and changes in a population over time.
What is a density dependent population growth method?
This method is applied to display the maximum attainable density that incorporates constraints to a population growth.
What is a density independent population growth method?
A simple method that assumes the population is not constrained by limiting factors
What are the main limits to populations in time and space
Environmental limiting factors (Abiotic) - Biological interaction limiting factors (Biotic)
What are some environmental limiting factors?
Physical changes: Temperatures - water - natural disasters - landscape changes (Abiotic).
Availability of suitable habitats (Mainly reproduction)
What are some Biological interaction limiting factors?
Food supply - Abundance/Distribution of predators - Diseases - Other species - Life expectancy
What is the body size to population density equation
Log(population density) = a + b x log(body weight)
How can habitat limitation effect population size?
A reduction in reproductive habitats with have a large impact on population size, resulting in a decrease or increase in a populations size
How does the interaction of pray and predators effect population size?
A reduction in predators will allow pray species populations to exponential grow until they reach their carrying capacity. Example, Red kangaroos and dingos.
What limiting factor plays the largest role in ecosystems?
Humans activities
What is a demography?
Size and structure of populations and changes with in populations
Why is it important to understand the age structure of a organism?
Age structures will give you the life expectancy of the organism, and this directly effects populations size and growth
What is r selected reproduction
The all or nothing approach. Low maternal care, while producing large amounts of offspring in hopes some will survive
What is K selected reproduction
Few young, high care approach. High maternal/parental care, allowing for the offspring to have a greater chance of survival.
What are the 2 keys drivers that changes population
Survival and mortality.
What significant data is recorded in life data?
Mortality/Survivor-ship - Age structure - Number of individuals at a set age.
What are the assumptions of exponential growth?
Must be a closed population - No constraints in growth
What is density-independent growth?
Organisms within an environment that have unlimited resources - no competitors or predators, and will keep increasing will no limit (Exponential)
What is density-dependent growth?
Accounts for the ‘upper limit’ to the population growth.
As population size increases beyond a ‘certain point’
Birth rates decrease and/or death rates increase (Logistic)
What happens when a population approaches the carrying capacity (K)
As the population gets close to a carry capacity the rate of increase in the population will slow down
What is symbiosis?
Interactions between two different organisms living in close physical association, typically to the advantage of both
What is commesalism?
One species benefits from the relationship and the other is not harmed-(This relationship can change over time)
What is mutualism?
Both organisms benefits from the relationship with nether being harmed
What are sub-categories of mutualism
Obligate mutualism and Faculative mutualism
