Lecture 10 - DA Flashcards
What kind of interaction is competition?
Harms both parties involved.
What kind of interaction is predation/parasitism?
Harms one, benefits the other.
What kind of interaction is mutualism?
Benefits both parties.
What kind of interaction is commensalism?
Benefits one, doesnt affect the other.
What kind of interaction is ammensalism?
Harms one, doesnt affect the other.
Define intraspecific competition and interspecific competition.
Intra - competition between individuals of a single species for resources.
Inter - competition between two different species for resources.
Define resource exploitation.
Reducing resources available for a competitor.
Define interference competition.
Preventing a competitor from accessing a resource.
Define symmetrical competition.
When the magnitude of impact on each species is the same.
Define asymmetrical competition. What does this mean for one of the species?
When the magnitude of impact on each species is the different. Therefore one species is competitively different.
What is the zero growth isocline? What happens if above or below the isocline?
Is a solid linear relationship, where the two axes represent abundances. If above the isocline, growth will be negative and will drop to the isocline. If below, the growth is positive, and will rise to the isocline.
If species 1 isocline is above species 2, what 2 things can be said?
Species 1 always excludes species 2
Species 1 is always a superior competitor
What can be said if two species isoclines are in stable equilibria? What determines where things will go eventually, and where is the site of unstable equilibria? What does this kind of relationship indicate about intra/interspecific competition, and what does this suggest about which species can exclude the other?
Species at an initial disadvantage will be excluded. The intersection is the site of unstable equilibrium, and a slight deviation will send it off on a trajectory.
Indicates individuals of a species compete more strongly with other species versus members of their own species.
Therefore both species can exclude each other, depending on who has the initial disadvantage.
What is coexistence on an isocline? What does this suggest about inter/intraspecific competition?
Is similar to a stable equilibrium, but there is no initial disadvantage, and therefore there is no capability to exclude one another.
Individuals of a species compete amongst themselves more strongly versus members of another species.
Name the four outcomes in terms of isoclines.
Predictable exclusion of one species x2
Exclusion dependent on initial density
Stable coexistence
When does stable coexistence occur?
Only when interspecific competition is weaker than intraspecific competition in both species.
What is interspecific competiton created by?
Niche overlap.
Define the competitive exclusion principle.
If the niche of two species overlaps entirely, one species will exclude the other.
What does coexistence require in terms of niches? What allows for coexistence aside (aside from competition parameters)?
Niche differentiation.
Environmental heterogeneity allows coexistence.
Define character displacement. Give an example.
Morphiological difference between populations of a species that are allotropic or sympatric with a competitor. Finches with different beak sizes allow for a different diet.
What effect does evolution have on competition?
Evolution acts to reduce competition.
What effect does niche differenciation have on competition?
Reduces competition.
What happens to a competitor when exclusion occurs?
Exclusion eliminates a competitor.
What can mask the presence of competition?
The consequences of competition.
