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> Which one are you suggesting has the shorter time scale?
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A good question. Species and nices co-evolve
together, and they influence each other.
The effects from the fitness landscape on the
agents and organisms of a species through natural
selection is certainly stronger and faster than vice
versa. Therefore you can approximately describe natural
selection as an adaptation to a fixed environment on a
short "biological" time scale.
Species - not organisms, individuals or agents
of that species - and niches interact on a similar
time scale. A species is defined as a class of organisms
that share common characteristics and can interbreed,
that is to say organisms which share a common
gene pool. It evolves slower than the corresponding
organisms and individuals.
Species and fitness landscapes change especially on
larger time scales, for example if habitats are altered
dramatically or if whole species are subject to
extinction. In fact mass extinction of species
occur if habitats disappear or vanish suddenly.
Species whose organisms and agents are able to find
and locate suitable habitats survive. Unsuccessful
species vanish.
A habitat is a form of a spatial niche for a species.
According to Niles Eldredge (*), habitats define the
environmental conditions to which organisms are accustomed.
Niles Eldredge writes in "Fossils", that species actively
seek and follow suitable habitats. He calls this
"habitat tracking". Rapid climate change (due to
catastrophes or other causes) is one of the main
cause for the alteration of habitats and the
occurence of mass extinctions.
Thus species, habitats, niches and fitness landscapes
seem to act roughly on the same "geological" time scale,
whereas organisms and individuals interact on a much
faster "psychological" and "biological" time scale.
(*) See
Fossils - The Evolution and Extinction of Species
Niles Eldredge
Houghton Mifflin Australia, 1991
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