Week #6 Flashcards
What is the general formula for population growth?
r = (b-d) + (i-e) | r = rate of population increase | b = birth rate | d = death rate | i = immigration | e = emigration
T/F - Exponential growth has a growth limit?
False, exponential growth has no growth limit BUT will eventually reach a limit because of shortages
What is carrying capacity (K)?
Maximum # of individuals an environment can support
What is the K of Earth?
About 10 billion
What is the shape of an exponential growth curve?
A “J”
What is the formula for logistic growth?
dN/dt = rN (K – N)/K | dN/dt equals the intrinsic rate of natural increase | r = intrinsic rate of increase | N: # of individuals in population
What is the shape of a logistic growth curve?
A “S”
T/F - Populations stop growing as soon as they hit carrying capacity?
False - Populations may go above or below the carry capacity line BUT growth does slow as the line is neared
What is R/K Selection Theory?
It’s a way to describe how a species controls its offspring. R-selection species produce many. Whereas, K-selection species focus on a few and run into carrying capacity (K) issues. However, neither method is “superior”.
What are some characteristics of r-selected species?
Mature early, lower longevity, decreased parental care, decreased competition, more offspring, smaller offspring
What are some characteristics of k-selected species?
Mature late, greater longevity, increased parental care, increased competition, fewer offspring, larger offspring
Is human population growth exponential or logistic?
Exponential
What is “Ecological Footprint”?
A measure of how much the environment is impacted by human activities
What is the ecological footprint of humanity?
About 1.6 Earths
What is community ecology?
The study of how specie populations interact within a particular area or habitat
What are the four types of competition?
Intraspecific, Interspecific, Interference, Exploitative
What is Intraspecific Competition?
Competition within a species
What is Interspecific Competition?
Competition between species
What is Interference Competition?
Direct, physical interactions over resources (can occur between two species or within a species)
What is Exploitative Competition?
Interact indirectly by consuming same resources
What is the Competitive Exclusion Principle?
Two species cannot occupy the same niche in a habitat (different species can’t coexist in a community if they are competing for all the same resources)
What experiment is an example of the Competitive Exclusion Principle?
G.F. Gause’s classic experiments using 3 Paramecium species | determined there can only be “one winner”, when alone growth was symmetric, when together growth was asymmetric
What is a niche?
total range of conditions under which an individual (or population) lives and replaces itself
What is a realized niche?
actual set of conditions under which an organism exists (think angry birds specific tree elevation)
What is a fundamental niche?
entire set of optimal conditions under which an organismic unit can live and replace itself (think entire angry birds tree) | ex. J.H. Connell’s study of barnacles
What is resource partitioning?
Similar species in same geographic area divide niches to avoid direct competition | results from natural selection | plays a role in adaptive radiation | ex. Anole Lizards and Darwin’s Finches
What is character displacement?
the evolutionary process where two similar species living in the same area develop distinct traits, like different beak sizes or feeding behaviors, to reduce competition for limited resources
