Test 2 - Species Interactions Flashcards
Name the 6 species interactions
- Competition
- Predation
- Herbivory
- Parasitism
- Disease
- Mutualism
Definition of Competition
two organisms use the same resource, or seek that resource, to the detriment of both
Disease
an association between a pathogenic microorganism and a host species in which the host suffers physiologically
Predation
one animal species eat all or part of a second animals species
Herbivory
one animal species eat all or part of a plant species
Parasitism
two species live in a physically close, obligatory association in which the parasite depends metabolically on the host
Mutualism
two species live in close association with one another to the benefit of both
Resource Competition
Last test should remember
occurs when a number of organisms, of the same or different species, use common resources that are in short supply
Interference Competition
occurs when the organisms seeking a resource harm one another in the process, even if the resource is not in short supply
Gauses hypothesis
“As a result of competition, two similar species scarcely ever occupy similar niches, but displace each other in such a manner that each takes possession of certain kinds of food and modes of life in which it has an advantage over its competitor
When does competition exclusion occur in labs (3 things)
- environment is unstable - not reached equilibrium
- Resources are not limiting
- The environment fluctuate such that direction of competition reverses before extinction
Why in stable environments do species often live together
- Competition was always rare in nature - resources often not limiting
- Competition has been common in nature but could adapt away
how do Dendroica warblers survive alongside each other
- Feed at different positions on tree
- different areas
- different ways of moving
How do they feed alongside each other - tern species on Christmas island
Same way and resources but different sized fish depending on beak size
If observed differences in resources need to know if …
- Competitions in past
2. Speciation
Where is strength of competition mostly seen
Herbivores
Due to competition how can species diverge where they occur
- reinforce reproduction barriers in closely related species
- If overlap character differences may mean they keep distance
Beak sizes of Darwins finches characteristics
Fortis and fuliginosa when separate very similar but when together fortis beak bigger and vice vera
r-selected animals
Seldom suffer pressure from interspecific competition during colonization and establishment - evolve no competition
Evolove to invest enery in reproduction - small
k-selected animals
Suffer pressure from interspecific competition at or near the carrying capacity
evolve to get bigger have less offspring but invest in offspring
what is a competitive strategy and give an example
Low intensity of stress and intensity of disturbance
e.g trees
(k)
What is a ruderal strategy
Low intensity of stress and high intensity of disturbance
e.g weeds
What is a stress-tolerant strategy
High intensity of stress and Low intensity of disturbance
e.g evergreen