Adaptation

An inherited trait that helps an organism survive.

Evolution

The process of how organisms acquire adaptations over time.

Ancestor

An organism from which others have descended

Cladogram

A tree like diagram that displays revolutionary relationships among living spices and their ancestors

Homologus structures

Body structures that have a common origin but do not necessarily perform the same function.

Vertebrate

Animals with a backbone

Fossil

A remnant or trace of an organism from the past, such as a skeleton or a leaf imprint, embedded and perserved in earths crust.

Fossil record

A historical sequence of life based on the sequence of fossils.

Natural selection

The process by which organisms with favorable adaptations survive and reproduce at a higher rate than organisms with less favorable adaptations.

Invertebrate

Animals without a backbone

Genetic variation

The variety of alleles in a population

Extinction

this occurs when the environment changes and the adaptations of a species are no longer sufficient for its survival.

Uniformitariansim

Using the present as a key to the past is consistent with the idea of

Mass extinctions

Periods of large scale extinctions

Absolute dating

A method of estimating the age of a rock sample in years

Half life

The amount of time it takes for half of the unstable atoms in a sample to decay.

Geologic time scale

A model of the history of life on earth.

Geology

The study of earths formation and structure.

Rock cycle

The process of rock formation and recycling.

Superposition

The principle that states that in lawyers of sedimentary rocks the lowest layer were the earliest to be deposited.

Relative dating

A method of sequencing events in the order in which they happened

Paleontologist

A scientist who studies fossils

Pangea

An ancient supercontinent that broke apart to fro today’s continents

Plate tectonics

A theory that describes how the continents move

Lithospheric plates

Giant pieces of solid rock on earths surface.