Unit 5 - Ecosystem Change (Evolution & Succession)

Evolution

a long, slow change in the characteristics of a population of organisms over time

Organisms Evolve:

as a group

Natural Selection

the idea that individuals that have traits that better suit their environment are more likely to survive and produce offspring

Fitness

the combination of physical and behavioral traits that help organisms survive and reproduce in their environment

Steps of Natural Selection

Overproduction, Variation, Selection, and Adaption

Overpopulation

ensures that a population will continue and not go extinct

Variation

a different or distinct form or version of a trait passed from parent to offspring

Adaption

an inherited trait that is present in a population because the trait helps individuals survive and reproduce in a given environment

Structural Adaption

traits that involve physical structure of an organism

Functional Adaption

traits that involve functions of an organism

Behavioral Adaprion

traits that are specific actions

Ecological Succession

a gradual process of change and replacement of the type of species in an ecosystem

Primary Succession

no previous life or ecosystem

Secondary Succession

ecosystem is disturbed and must rebound

Pioneer Species

first organisms to appear in a newly made habitat

Climax Community

one that does not undergo further succession, usually highly diverse, and able to sustain local disturbances

Evolutionary Arms Race

the evolutionary struggle between competing sets of co-evolving species that develop adaptions and counter-adaptions against each other