EVIDENCE OF EVOLUTION

Fossil Records

Remains or traces of organisms years ago, found in rocks and sediments.

Compression

A type of fossil formation where the organism is flattened, and preserved by sediment.

Petrification

A type of fossil formation where the the bones of an organism is buried, and water containing mineral passes through it, converting the organic matter to mineral/stone.

Impression

A type of fossil formation where an organism dies, leaving an impression in the mud. Mud hardens to rock, revealing the organism.

Cast

A type of fossil formation where an organism dies and sinks into soft sediment, organism decays and the imprint in the sediment is filled with mud. It hardens, leaving a cast of the organism.

Intact Preservation

A type of fossil formation where insects are trapped in tree sap or amber that preserves their original form without decay.

Transitional Fossils

Fossils that exhibit resemblance to two organisms in the present that are classified separately. They provide evidence of evolutionary change by showing intermediary forms between ancestral species and their descendants.

Why are fossil records always incomplete?

• No trace of fossil

• Plates always moving

• Hard to discover

Biogeographical Evidence

The geographical distribution of similar fossils and organisms even though they are not near one another geographically. This evidence shows how species evolve to adapt to their environment over time.

Anatomical evidence

Structural similarities in organisms that indicate common ancestry, such as homologous structures and analogous structure.

Homologous structures

Anatomical evidences that are differing species with bones that share similarities, indicating that they come from a common ancestor.

Analogous Structures

Anatomical evidence that shows that some structures have the same purpose and function but have different bone structure.

Vestigial Structure

Anatomical evidence that shows that some structures and parts of the body are fully developed in one species, but nonfunctional in the other.

Embryology evidence

The study of embryonic development across different species, showing similarities that indicate common ancestry.

Molecular Evidence

Organisms that have similar molecule structures indicating a shared ancestor.