How to build a cladogram from an outline
The outline box is the whole interface. Indentation is nesting: a line indented under another line is inside that clade. The vertebrate cladogram above starts at Vertebrata, splits into the jawless lamprey and Gnathostomata (the jawed vertebrates), and keeps splitting — Osteichthyes into ray-finned and lobe-finned lineages, Tetrapoda into amphibians and amniotes, Amniota into reptiles (birds included) and mammals — until each branch ends in a single organism.
- Line 1: the outgroup-inclusive root, the broadest group in your analysis.
- Indent one level for each descendant clade. Two sister groups sit at the same indentation under the same parent.
- Keep naming internal nodes if your assignment asks for clade names; leave them off and indent taxa straight under their ancestor if it doesn't.
- Tab and Shift+Tab move a line and everything nested under it, so re-rooting a group is two keystrokes rather than a redraw.
- Download the PNG, or copy it as a plain-text tree for a lab write-up.
Cladogram conventions worth getting right
- Sister groups, not ladders. Two taxa are sisters when they share a node no one else shares. Reading a cladogram left to right as "most primitive to most advanced" is the classic misreading — a lamprey is not an early draft of a human, it is the other side of a split.
- Rotation is free. Swapping two sister branches produces the same cladogram. If your teacher's version looks flipped compared to yours, check the nodes, not the order of lines.
- Include an outgroup. The root is only meaningful relative to a group outside the one you're studying; the outgroup is what tells you which character states are ancestral.
- Use the bare layout. This page loads the Linguist theme, which draws plain lines with no boxes around labels — the look used in biology textbooks. The left-to-right direction puts the taxa in a readable column on the right; switch to top-down if you need a portrait figure.
Marking shared derived characters
Cladograms are usually annotated with the synapomorphies that support each split. Put the character in square brackets at the start of a line and it becomes a label on the branch leading into that group — [jaws] Gnathostomata, [amniotic egg] Amniota, [hair] Mammalia. The label rides with the branch when you move the line, so the annotation never drifts away from the node it belongs to.
Cladogram or phylogenetic tree?
The two words are often used interchangeably in coursework, and the same outline draws both here. The distinction that matters: a cladogram encodes only the branching order, while a phylogenetic tree may also scale branches to time or genetic change. If you need the tree with divergence information attached, start from the phylogenetic tree maker, which loads a primate phylogeny instead of this vertebrate cladogram. For hierarchies that have nothing to do with evolution, the tree diagram maker is the general version of the same engine, and family tree diagrams handle the other kind of ancestry — the one with names in it.