Ecological Niches and Adaptation Occupation Ecological niche Total

Ecological Niches and Adaptation Occupation • Ecological niche – Total way of life or functional role of a species in an ecosystem. Address • Habitat – Physical location of a species

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 Procyon lotor • Can live in many different places • Eat a variety of foods • Tolerate a wide range of environmental conditions • Makes them better adapters! Brown Rat Racoon 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