11.21

Fundamental niche: the total theoretical niche
Realized niche: the portion of the fundamental niche that a species actually occupies
Joseph Connell observed patterns along rocky Scottish coast in barnacles
Upper Intertidal Zone: adults of one barnacle species occurred here
Lower Intertidal Zone: adults of the other species were restricted here
The young of both species were found together in the Lower Zone
Were the adults not found at each place due to physiological limitations or competition from the other species?
This supported the competition hypothesis: the presence of one strong competitor species excludes the presence of the weak competitor species
The fundamental niches of the two species overlap
Fitness trade-offs prevent species from completely taking over
The ability to compete for a resource requires time and energy, which means being a superior competitor translates to worse fitness
There is strong natural selection to avoid competition
A reduction in niche overlapped can be favored over evolutionary time
This process is called niche differentiation
Galapagos finches are a great example of this!

Consumption

Occur when one organism eats another
Predation/herbivory/parasitism
(+ / -) interaction
An agent of natural selection

Endoparasite: consumes a relatively small amount of tissue or nutrients from inside a host, typically over a long period. Tapeworms

Ectoparasite: consumes a relatively small amount of tissue or nutrients from outside a host, typically over a long period. Ticks

Parasitoid: free living as an adult but endo- or ecto- as larvae, hatching from an egg laid inside or on a host and consuming the host, eventually killing it.

Batesian mimics: look dangerous, are not dangerous
Mullerian mimics: look dangerous, are dangerous