4.4 Evidence of Evolution

Definitions of Key Terms for 4.4

The Origin of Species

A book by Darwin that compiled evidence for evolution and introduced the theory of evolution by natural selection.

Fossil Record

A historical record of life on Earth, created by fossils found in sedimentary rock, showing different species that existed in the past.

Burgess Shale

A fossil bed in British Columbia containing ancient marine fossils from the Cambrian Period, over 500 million years ago.

Evolutionary Change

The gradual process by which species change over time, often taking millions of years.

Transitional Fossils

Fossils that show intermediary links between groups of organisms, helping to understand evolutionary relationships.

Vestigial Structures

Reduced forms of structures that were functional in an organism's ancestors, such as the pelvic bone in modern whales.

Biogeography

The study of the geographical distribution of organisms, supporting the idea that species evolve in one location and spread to others.

Homologous Structures

Anatomical features in different species that have similar origins but different functions, indicating a common ancestor.

Analogous Structures

Body parts that perform similar functions but do not share a common evolutionary origin, such as insect wings and bird wings.

Embryology

The study of early developmental stages of organisms, showing similarities in embryos of related species that suggest a common ancestry.

DNA Evidence

Genetic similarities between species that indicate evolutionary relationships, with closely related species sharing similar DNA patterns.

Natural Selection

The process by which traits that enhance survival and reproduction become more common in a population over time.

Plate Tectonics

The movement of Earth's tectonic plates, explaining the geographical distribution of fossils across continents.

Archaeopteryx

A transitional fossil that exhibits characteristics of both reptiles and birds, providing evidence for the evolution of birds from reptiles.

Common Ancestor

An ancestral species from which multiple species have evolved, as indicated by similarities in anatomy, embryology, and DNA.