VOCABULARY WORDS

Evolution

process through which species change over time.

Abiotic

Nonliving factors in an organism’s environment

ex. Temperature, rainfall, sunlight

Biotic

living factors in an ecosystem. Ex. Trees, insects, grass

Adaptation

A characteristic or any inherited trait that makes a species better suited to survive and reproduce in its environment

Habitat Natural environment in which a living

thing gets all that it needs to live Ex. Deserts, rainforest, coral reef, lake

Natural Selection

The process through which members of a species that are best suited to their environment survive and reproduce at a higher rate than other members of their species.

Mass Extinction

One of several periods in Earth’s history when large numbers of species became extinct at basically the same time.

Population

A group of organisms of the same species.

Succession

A natural process that involves a gradual change in the plant and animal communities that live there.

Vestigial Organ

a physical structure that was fully developed and functional in an earlier group of organisms but is reduced and unused in later species.

Speciation

The evolution of a new species from an existing one

Mutation

A change in an organism’s DNA

Ancestor

A distant or early form of an organisms from which later forms descend

Fossil

The imprint or hardened remains of a plant or animal that lived long ago

Limiting Factor

Factor or condition that prevents the continuing growth of a population in an ecosystem

Isolation

Separation of a population of organisms from related forms in such a manner to prevent crossbreeding

Extinction

The permanent disappearance of a species

Population Dynamics

The study of the changes in the number of individuals in a population and the factors that affect those changes

Carrying Capacity

Maximum number of a species that an ecosystem can support

Population density

Measure of the number of organisms that live in a given area

Ex. 15 rabbits per sq km

Population Size

Number of individuals of the same species that live in a given area

Immigration

Movement of an organism into a range inhabited by individuals of the same species

Emigration

Movement of individuals out of an ecosystem

Opportunists

Species characterized by a relatively short life span, with relatively large numbers of offspring

Competitor

A species characterized by a relatively longer life span, with relatively few offspring, when compared with an opportunist species.

Pollution

The release of harmful substances into the air, water, or land.