Phylogenetic trees and cladograms

A phylogenetic tree is a branching diagram that shows scientists' best hypothesis of how groups of organisms are related through evolution. The tips of the branches are living or extinct groups, each branching point (node) represents a common ancestor, and groups that branch from a more recent common ancestor are more closely related. A cladogram is a kind of phylogenetic tree built from shared derived characteristics, traits that appeared in a common ancestor and were passed on to its descendants but are not found in more distant groups. For example, a backbone is shared by fish, frogs, lizards, and mice, while four limbs are shared only by frogs, lizards, and mice, so those three share a more recent ancestor with each other than any of them does with fish. A clade is an ancestor and all of its descendants. Today scientists build trees mainly by comparing DNA and protein sequences, since more similar sequences usually mean a more recent common ancestor, and they revise the trees as new evidence appears. Phylogenetic trees show relationships, not a ladder of progress: every living group's ancestry reaches back equally far to the origin of life, so no living group is more evolved than another.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report