AchievedDescribing:
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MeritExplaining:
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ExcellenceLinking:
The linking of ideas may involve justifying, relating, evaluating, comparing and contrasting, and analysing. |
Responses include:
- orientation in space (tropisms, nastic responses, taxes, kineses, homing, migration)
- orientation in time (annual, daily, lunar, tidal rhythms)
- interspecific relationships (competition for resources, mutualism, exploitation including herbivory, predation, and parasitism)
- intraspecific relationships (competition for resources, territoriality, hierarchical behaviour, cooperative interactions, reproductive behaviours).
External environment:
Abiotic factors (non-living)
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Biotic factors (living)
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Ecological niche:
Every species on Earth occupies an ecological niche. A niche is more than a habitat, it is
If two different species share the same ecological niche, they will compete with each other until one dies out. Unless one species alters its niche slightly. For example, below are some warbler birds. They eat the same food, live in the same habitat, sing the same songs, however their niches are slightly different, which allows them to coexist in the tree and not outcompete each other.
- the function the species carries out in that habitat (i.e. decomposer, consumer, predator)
- the way the species uses available resources
- how its existence affects other community members
If two different species share the same ecological niche, they will compete with each other until one dies out. Unless one species alters its niche slightly. For example, below are some warbler birds. They eat the same food, live in the same habitat, sing the same songs, however their niches are slightly different, which allows them to coexist in the tree and not outcompete each other.
Fundamental niche
Each organism has a fundamental niche that it could occupy - that is if everything it needed was in abundance; abiotic conditions were ideal and predation etc. was not present. An organism's fundamental niche is only limited by its physiological tolerances (i.e. if temperature got too high in that area, the organism would not live there and thus limiting where it can exist) Pretty much no organisms live in their fundamental niche - it is like imagining the perfect life! |
Realized niche
Realistic niche - this is the niche an organism actually occupies. This takes into account the real-life limitations imposed onto the organism, such as competition for resources, predation, etc. |
Example: Two species of birds live in the rainforest and eat a particular type of stripey worms that live on the forest floor. Both of these birds build nests in the mid-canopy area of the forest (halfway up) and are active at dawn and dusk. Both species of birds have quite long beaks, which help them to clamp on to the wriggly worms that they feed on. These birds are both preyed upon by forest cats, who catch the birds as as they come down to find their worms. These two bird species occupy identical ecological niches. One would eventually out-compete the other. Instead, one of those species may fill a new niche, though this niche may be similar to the previous one. By changing the type of worms it ate, or the time of day it is active - the bird is changing its ecological niche. This reduces the overlap between species and makes it more likely that they would co-exist, rather than one species survive and the other be eliminated.
If one bird species changed from eating the stripey worms to eating plain worms, or even to eating caterpillars instead, this could lead to more differences between that species and the other bird species, such as time of day where they are active (could reduce likelihood the forest cat would catch it) - further removing the overlap between bird species and allowing them to both live successfully in their habitat (the forest).
If one bird species changed from eating the stripey worms to eating plain worms, or even to eating caterpillars instead, this could lead to more differences between that species and the other bird species, such as time of day where they are active (could reduce likelihood the forest cat would catch it) - further removing the overlap between bird species and allowing them to both live successfully in their habitat (the forest).
Adaptive advantage
This term refers to the advantage an organism has over others, in their particular environment. Perhaps they respond in a way that gives them a greater chance of survival, allowing them more opportunity to reproduce. If this happens, they have an adaptive advantage over the other members of their species, or perhaps other species.