Interactions between populations Flashcards
What is neutralism?
No effect on either species
What is commensalism?
An increase in one species and no effect on the other
What is competition?
A negative effect on both species
What is mutualism?
A positive effect on both species
What is predation?
A positive effect on one species and a negative effect on another species
What is predation and paracitism?
A positive effect on one species and a negative effect on another species
What is the effect of limited resources?
Leads to competition and effects growth rate
What is intraspecific competition?
Competition between the same species
What is the effect of intraspecific competition?
Keeps population steady but is intense as same requirements and same means of obtaining them
What is the importance of intraspecific competition?
Keeps best selected for natural selection
What is interspecific competition?
Competition between different species
When does interspecific competition occur?
When 2 niches overlap and the greater the overlap, the more likely competition will occur, and when new species are introduced it competes with existing species
What is the effect of interspecific competition?
Either one species wins, or it is shared
What is the competitive exclusion principle?
One species ‘wins’ and one species ‘loses’
When is coexistence of species possible?
When there is no-overlap of niches
How can interspecific competition affect natural selection?
Evolution by natural selection occurs towards separate niches occurs so they are as different as possible to minimise competition
What is the result of very heavy competition?
Too much overlap leads to competitive exclusion so one species must go
What happens with species with different size niches?
A species with a smaller niche can avoid competition as it is more specialist
What are important for controlling population?
Predation and competition
What is a predator?
An organism that eats part of all of another organism
What is a prey?
An organism that gets eaten by another organism
What does the prey graph look like?
Identical waves, with the predator line being delayed by the prey line
