Bio: Cladistics

Cladistics

A method of classification of animals and plants according to the proportion of measurable characteristics they have in common.

Clade

A group of organisms that includes a common ancestor and all its descendants.

What is the significance of a clade in cladistics?

It represents a group of organisms linked by their shared common ancestor.

Cladogram

A tree diagram that shows the most probable sequence of divergence in clades and insights into evolutionary relationships.

What do branching points in a cladogram indicate?

They indicate the last common ancestor between species.

What is LUCA?

Last Universal Common Ancestor, the ancestor of all life on Earth, believed to have formed about 4 billion years ago.

Extant organisms

Organisms that still exist today, found on the horizontal line at the top of a cladogram.

Extinct organisms

Organisms that no longer exist, positioned lower down in a cladogram.

Key trait on a cladogram

A trait that is evidence for evolution placed between organisms on a cladogram.

Evolutionary trees

Diagrams that illustrate the assumptions that all of life evolved from a common ancestor.