Ecological Niches and Adaptation Occupation Ecological niche Total way of life or functional role of a species in an ecosystem. Habitat Physical location of a species Address
Niches!! Fundamental Realized The full range of environmental conditions (biological and physical) under which an organism can exist Narrower niche, a result of pressure from, and interactions with, other organisms (e.g. superior competitors). They are mostly highly adapted to this one According to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time.
Generalist Species Can live in many different places Procyon lotor Racoon Brown Rat Can live in many different places Eat a variety of foods Tolerate a wide range of environmental conditions Makes them better adapters! Homo sapiens Human
CONSIDER THE COCKROACH Periplaneta americana Cockroaches Eat anything! (algae, dead insects, electrical cords, glue, paper, soap Live and breed anywhere (except polar regions) Can go months without food! Real good at hiding! High reproductive rates!
Specialist Species Live in only one type of habitat Use only one or a few types of food Tolerate only a narrow range of environmental conditions Makes them more prone to extinction due to environmental change!
CONSIDER THE KOALA Only eats eucalyptus leaves What would happen if there were no more eucalyptus?
Patterns of Evolution
Gradualism Intermediate forms between extant (living) and extinct species Species evolve slowly, small changes add up
Punctuated equilibrium S J Gould Periods of rapid divergence alternating with periods of stability