Key Evolutionary Biology Terms: Phylogenetics, Fossils, and Natural Selection

Uniformitarianism

Present processes explain the past

Stratigraphy

Study of rock layers

Taxonomy

Classification of organisms

Paleontology

Study of fossils

Extinction

Species dies out

Theory

Well-supported explanation

Hypothesis

Testable prediction

Natural selection

Survival of best-adapted

Sexual selection

Traits that improve mating success

Heredity

Passing traits to offspring

Genetic drift

Random change in gene frequencies

Modern evolutionary synthesis

Darwin + genetics

Adaptation

Trait that improves survival

Stromatolite

Ancient microbial structure

Exaptation

Trait evolves for one use, used for another

Homology

Shared ancestry (e.g., arm, wing, flipper)

Monophyletic group

Includes all descendants of one ancestor

Polyphyletic group

Excludes common ancestor (bad grouping)

External node (tip)

Living species

Internal node

Common ancestor

Clade

A complete branch of life

Branch

Evolutionary lineage

Polytomy

Uncertain branching

Synapomorphy

Shared derived trait