Notes 7-5

Branching Tree Diagrams

Branching Tree Diagrams

• Organisms with similar characteristics may be descended from a common ancestor

• The more similar the organisms are, the more recent the common ancestor probably is

A Branching Tree• Branching trees such as this show

relationships between groups of organisms. It also shows the order in which specific characteristics may have evolved.

Backbone

Four Limbs

Egg with shell

Cladogram

• A branching tree diagram is sometimes referred to as a cladogram

Shared Derived Characteristics

• Homologous structure that is shared by all organisms in a group.

• What do the organisms below all share? (What is their homologous structure?)

BACKBONE

Shared Derived Characteristics• A branching tree diagram shows evolutionary

relationships by grouping organisms according to shared derived characteristics.

ReptilesAmphibians

Egg with shellFishes

Four limbs

Backbone

Invertebrates

Ancestor of animals

Which of these characteristics probably developed first?

The Great Tree Of Life