Tree

Newick: group related species in parentheses; add :0.5 after a name for a branch length. Or just list species, one per line.

Newick

Cladogram maker

Type a list of species or a nested group written with parentheses and this cladogram maker draws the branching diagram at once: every organism on its own tip, every shared ancestor at a node, ready to download as PNG or SVG. It is built for biology classes, where the question is usually who is more closely related to whom, not how many million years ago they split.

What a cladogram shows

A cladogram is a hypothesis about evolutionary relationships. Reading from the root, each node is the most recent common ancestor of everything to its right, and the group descending from one node is a clade. Two species that join at a node near the tips are close relatives; a species whose branch leaves the trunk first is the outgroup. Branch lengths carry no meaning here, only the order of the splits does, which is why a cladogram can be redrawn with any spacing without changing what it says.

Shared derived traits

Biologists place organisms on a cladogram by the traits they share with a common ancestor but not with earlier lineages, called shared derived traits or synapomorphies. The example tree does exactly this for vertebrates: the lamprey branches off first because it has no jaws; the shark has jaws but no bony skeleton; the salmon adds bone; the lizard adds four limbs and a shelled egg; and the mouse and human sit together on the last node because both have fur and feed their young milk. Each trait appears once, at the node where it evolved, and every species beyond that node inherits it.

How to write the nesting

The maker reads the same bracket notation as the phylogenetic tree maker: wrap the two closest relatives in parentheses, then wrap that group with the next relative, and so on outward. (Shark,(Lizard,(Mouse,Human))); is the shark plus a clade, that clade is the lizard plus a smaller clade, and the innermost pair is mouse and human. If you would rather not write brackets at all, type one species per line; the tool then pairs neighbours into a balanced tree, so Human, Chimp, Gorilla becomes ((Human,Chimp),Gorilla) and you can rearrange the names until the branching matches your data.

How to use the cladogram maker

Frequently asked questions

What is a cladogram?

A cladogram is a branching diagram of evolutionary relationships. Every branch point stands for a common ancestor, and the organisms that descend from it form a clade. It shows the order in which lineages split, not how long ago or how much they changed.

How do I make a cladogram from a list of species?

Type one species per line and the maker pairs neighbours into a balanced tree, or write the nesting yourself with parentheses: (Shark,(Lizard,(Mouse,Human))); puts mouse and human closest, lizard next and shark on the outermost branch.

What is a clade?

A clade is an ancestor together with all of its descendants, one complete branch of the cladogram. Mammals are a clade; reptiles as traditionally defined are not, because birds descend from the same ancestor but are left out.

What is the difference between a cladogram and a phylogenetic tree?

A cladogram shows branching order only, so all its branches can be drawn the same length. A phylogram is a phylogenetic tree whose branch lengths are proportional to time or to the amount of genetic change. Add a length after each name, such as Human:0.6, and the phylogenetic tree maker draws it to scale.

Can I download the cladogram?

Yes. Download it as PNG or JPG for a worksheet or slide, or as SVG to edit the labels and colours in any vector program. The share button copies a link that reopens the same tree.