Cladogram Maker
A cladogram maker that groups organisms into nested clades by shared derived traits, drawn as a teaching ladder, a rectangular tree or a tree beside its character matrix. Built for evolution worksheets and lab reports.
Cladogram examples
Five ways the cladogram maker can draw the same kind of tree, each shown with a real render. Click a card to apply the style, or zoom for the full image.
What is a cladogram?
A cladogram is a branching diagram of how a group of organisms is related by descent. Each tip is a taxon, each branch point (node) is the most recent common ancestor of everything above it, and any node plus all its descendants is a clade. Branches are usually marked with the derived characters — synapomorphies — that first appear there, which is what makes the tree an argument rather than a picture: the nesting of shared characters is the evidence for the nesting of the groups.
A cladogram shows branching order only. Its branch lengths mean nothing, which is what separates it from a phylogram, where length is proportional to genetic change, and from a chronogram, where length is time. This cladogram maker produces the figure — describe the group in plain words, or paste the character table, and the AI resolves the topology and draws it ready for a worksheet, a lecture slide, a thesis or a paper.
Key facts
- A cladogram states branching order only — its branch lengths carry no meaning, so a long branch does not mean more change or more time.
- A clade is any node plus every descendant of that node; naming a clade means pointing at a node, not at a region of the drawing.
- Branches are marked with synapomorphies — derived characters that first appear at that node and are shared by everything above it.
- An outgroup is what tells the tree which end is the root; without one, the same branching pattern has no direction.
- Rotating the branches at any node produces a different-looking drawing of exactly the same tree.
- The cladogram maker follows the same rules: order only, traits at the node where they first appear, and an outgroup to root the tree.
How does the cladogram maker work?
Tell the cladogram maker the group
Name the organisms, paste a character matrix, give a Newick string, or just name the group, "the great apes". The cladogram maker works out the nested clades, using the accepted phylogeny when you have not specified one.
Pick a tree style
The cladogram maker offers five: the classic teaching ladder with a trait marked at every branch point, a clean rectangular tree for publication, the tree paired with the character matrix it came from, illustrated tips, or a whiteboard sketch.
Refine in the cladogram maker's workspace
The cladogram opens in your workspace, where you can edit regions, adjust labels, upscale and export in high resolution for handouts, slides, posters or papers.
Prompts that work in the cladogram maker
The cladogram maker accepts the same shapes of input a textbook exercise gives you. Six that cover most cases, each with what comes back.
Cladogram of the great apesThe cladogram maker uses the accepted phylogeny, puts the gibbon on the first branch and labels Hominoidea to Hominini at the nodes.
Lamprey, shark, salamander, lizard, mouseTaxa alone are enough. The cladogram maker resolves the order and marks the derived trait at each node.
Lamprey 0 0 0 0; Shark 1 0 0 0; Frog 1 1 0 0; Lizard 1 1 1 0; Mouse 1 1 1 1 (jaws, four limbs, amniotic egg, hair)The cladogram maker roots on the row with the fewest derived states and draws the tree beside the matrix.
((Gibbon,(Orangutan,(Gorilla,(Chimpanzee,Human)))));The cladogram maker draws exactly that topology and does not correct it.
Cladogram of the land plants, green alga as the outgroupNaming the outgroup tells the cladogram maker where the root goes when the table is ambiguous.
Archosaurs from crocodile to pigeon, illustrated tips, one silhouette per taxonStyle words at the end of the prompt override the capsule, so the cladogram maker can draw one tree five ways from the same text.
From a character table to a cladogram: how the cladogram maker reads it
The classic classroom task is a 0/1 table and the instruction "draw the cladogram". This is what the cladogram maker does with such a table, using five vertebrates and four characters.
| Jaws | Four limbs | Amniotic egg | Hair | |
|---|---|---|---|---|
| Lamprey | 0 | 0 | 0 | 0 |
| Shark | 1 | 0 | 0 | 0 |
| Frog | 1 | 1 | 0 | 0 |
| Lizard | 1 | 1 | 1 | 0 |
| Mouse | 1 | 1 | 1 | 1 |
- 1
Find the outgroup
The row with the fewest derived characters is the lamprey, every cell 0, so the cladogram maker roots the tree there and treats the other four as the ingroup.
- 2
Order the characters
Count the taxa that share each one: jaws four, four limbs three, amniotic egg two, hair one. The cladogram maker does this count for you; each count is one level of nesting.
- 3
Place each character at one node
Jaws goes on the branch after the lamprey splits off, four limbs after the shark, amniotic egg after the frog, hair on the mouse's own branch. Two characters with the same count would share a node.
- 4
Check for conflict
If a character were shared by shark and mouse but not by frog and lizard, no nesting would fit. The cladogram maker does not force one; it flags the character in the workspace note so you can decide whether it evolved twice or was scored wrongly.
- 5
Read the result
Lizard and mouse meet at the most recent node, so they are the closest pair. The shark is a closer relative of the mouse than the lamprey is, however the tips happen to be printed. That is also how to read any tree the cladogram maker returns.
Pick the Tree + character matrix style and the cladogram maker prints the table beside the tree, so a reader can check every mark against the data. The figure is that output for this table.
Nested groups and the tree say the same thing
A cladogram is a set of nested groups drawn sideways, and that is how the cladogram maker stores one before it draws. Every node is a box, every box inside a box is a branch inside a branch, and a taxon sitting alone in a box is the lineage that split off at that node. Exam questions that give you nested boxes, or a Venn diagram of shared characters, and ask for the tree are asking you to redraw the same information.
Working the other way is just as mechanical: start at the root, draw the outermost box, and step inward one node at a time. If you have the boxes but not the tree, describe them to the cladogram maker as groups, "Hominoidea contains gibbon and Hominidae; Hominidae contains orangutan and Homininae", and it draws the tree from the nesting.
The parts of a cladogram
Cladograms are readable across textbooks and journals because every one is built from the same handful of parts. These are the terms you will meet reading them, and the ones the cladogram maker can label for you:
Root
The base of the tree — the common ancestor of everything shown.
Node
A branch point: the last common ancestor of the lineages leaving it.
Branch
A lineage between two nodes. Its length carries no meaning.
Tip (taxon)
A terminal group — a species, genus or larger group being compared.
Clade
A node with every descendant it has, and nothing else.
Outgroup
The taxon outside the group of interest; it roots the tree.
Synapomorphy
A derived trait marked where it first appears, shared from there on.
Polytomy
Three or more lineages from one node — the order is unresolved.
One tree can be drawn many ways. A cladogram may be rectangular, slanted, or laid out as a ladder, and the branches at any node can be rotated freely — none of that changes the relationships it states. Two diagrams that look nothing alike can be the same tree. Ask the cladogram maker for any of these layouts and the nesting it draws is the same.
How to read a cladogram without misreading it
Almost every mistake with these diagrams comes from reading something into the drawing that the tree does not say, and no cladogram maker can stop a reader doing it. Three worth naming:
The right-hand taxon is not the most evolved
Position along the tips is a drawing convention, not a ranking. Every living tip has had exactly the same amount of time since the root — a moss is as modern as a sunflower. Rotate the branches at any node and the tree is unchanged.
Closeness is measured through nodes, not across the page
Two tips printed side by side can be distant relatives. What matters is where their lineages meet: the taxa sharing the most recent common ancestor are the closest, however far apart they sit.
Tips are not ancestors of other tips
A cladogram never says that one living group descended from another. Ancestors sit at the nodes, and those ancestors are hypothetical — inferred from the characters, not one of the organisms drawn at the tips. The cladogram maker never draws a tip as another tip's ancestor.
The five questions every cladogram worksheet asks
Cladogram practice sheets reuse the same five question types, whatever organisms they draw. Each has a mechanical answer once you know where to look, and once you can answer them you can also check a tree the cladogram maker has drawn for you.
- 1
Which two organisms are most closely related?
Find the most recent node that joins them. The pair sharing the youngest node is the closest, however far apart they are printed. Looking alike is not evidence: birds look more like bats than like crocodiles.
- 2
Which trait separates X from Y?
Trace both tips back to the node where they meet, then step one branch towards the more derived taxon. The tick on that branch is the trait X has and Y lacks.
- 3
Which organisms have trait Z?
Find the tick for Z and read every tip above it. A derived character is shared by all descendants of the node where it first appears, unless the tree marks a loss. The cladogram maker ticks each character once, so one tick means one node.
- 4
Where is the most recent common ancestor of X and Y?
At the node where their lineages meet. It is a hypothetical population, not one of the organisms at the tips, so the answer is a node, never a name.
- 5
Is this group a clade?
Only if it is one node plus every tip above it. A group that leaves some descendants out is paraphyletic; a group gathered from different branches is polyphyletic. Neither counts.
Try it on one tree
Four arthropods and a snail as outgroup, four derived characters, laid out the way the cladogram maker draws a staircase. Answer first, then open each line.
Which organism is the beetle's closest relative?
The grasshopper. They share the youngest node, the one marked wings. The silverfish also has six legs, but it branched off one node earlier.
Which trait separates the silverfish from the crayfish?
Six legs. Both have jointed legs; the tick after the crayfish branches off is six legs, which the silverfish has and the crayfish lacks.
Is "the wingless animals" (snail, crayfish, silverfish) a clade?
No. No node has exactly those three as its descendants; they are what is left when you remove a clade, which makes the group paraphyletic. Grasshopper plus beetle is a clade: the wings node and everything above it.
Paste the table from your own worksheet into the cladogram maker, pick Tree + character matrix, and check your answers against the tree it draws.
Three checks before you export from the cladogram maker
The cladogram maker draws what you ask for, including a tree that is wrong. Three things worth a glance before the figure goes into a handout or a thesis. Each takes the cladogram maker one more sentence to fix.
The outgroup stands alone and branches first
If the cladogram maker has put it inside the ingroup, one character in your table is scored the wrong way round. Flip it and regenerate.
Every named clade is a node plus all of its descendants
"Reptiles" drawn without birds is not a clade. The cladogram maker will label the group if you ask, so the name is your responsibility, not the tool's.
Each character appears once
A trait marked on two separate branches means the cladogram maker read it as having evolved twice. If that is not what the data say, rename the character or merge the rows and run it again.
Cladogram maker or phylogenetics software?
People reach for a cladogram maker and for phylogenetics software for different jobs, and the quickest way to choose is to ask what you are starting from. If you have a sequence alignment and need a tree estimated from it, you need inference software. If you already know the relationships, or have a character table, and what you need is the figure, the cladogram maker is the shorter road.
| Cladogram maker | MEGA / IQ-TREE | iTOL | FigTree | |
|---|---|---|---|---|
| Starts from | A description, a character table or a Newick string | A sequence alignment | A tree file you already have | A tree file you already have |
| Produces | A finished figure in the cladogram maker style you pick | A tree with support values | A styled tree from your file | A styled tree from your file |
| Branch lengths | None, by design; the cladogram maker states order only | Estimated from the data | Kept from the file | Kept from the file |
| Bootstrap or posterior support | No | Yes | Shown if the file has them | Shown if the file has them |
| Trait marks, character matrix, illustrated tips | Yes, all three | No | Partly, through annotation files | No |
| Edit after drawing | Yes, in the cladogram maker's workspace | Re-run the analysis | Re-style only | Re-style only |
| Time to a usable figure | About a minute | Hours, plus model selection | Minutes, once you have a tree | Minutes, once you have a tree |
Use both when you need both. Estimate the tree in IQ-TREE, then hand the topology to the cladogram maker as a Newick string and let it draw the teaching version, with the traits marked and a silhouette at every tip.
Cladogram vs phylogenetic tree
A cladogram is one kind of phylogenetic tree — the kind that shows branching order and nothing else. In a phylogram, branch length is proportional to the amount of genetic change; in a chronogram, branch length is time. All three state the same relationships, but only the cladogram makes no claim about how much or how long. Asking whether a diagram is "a cladogram or a phylogenetic tree" is really asking whether its branch lengths mean anything.
| Cladogram | Phylogram | Chronogram | |
|---|---|---|---|
| Branch length means | Nothing | Amount of genetic change | Elapsed time |
| Tips line up | Yes, flush at the right | No — they end where their change does | Yes, at the present |
| Has a time axis | No | No | Yes, in years or millions of years |
| Built from | Shared derived characters | Sequence data plus a model | Sequences plus fossil calibrations |
| States branching order | Yes | Yes | Yes |
| Answers "how different?" | No | Yes | No |
| Answers "how long ago?" | No | No | Yes |
A cladogram is never "less accurate" than a phylogram — it makes fewer claims. If your data support branching order but not rates, a cladogram is the honest diagram to draw. It is also the only kind the cladogram maker draws.
Homoplasy, parsimony and polytomies
Real character tables are rarely as tidy as a worksheet. Three ideas cover almost every case where the data refuse to nest, and each comes with a drawing convention.
Homoplasy
A character shared by taxa that did not inherit it from a common ancestor. Wings in birds and bats are the classic case, convergence; a trait lost again, like legs in snakes, is a reversal. On the tree a homoplastic character appears on two separate branches, or appears and is later crossed out. Score it as it is; do not delete the column to make the tree tidier. The cladogram maker draws it on both branches when the table says so.
Parsimony
When two trees both fit the table, the one that needs fewer character changes wins. Count the steps: every place a character has to appear or disappear is one. Give the cladogram maker a table with a conflict and the workspace note names the character it could not place once; the parsimony call is yours, made by restating the groups.
Polytomy
A node with three or more branches leaving it says the order is unresolved, not that three lineages split at once. Draw one when your characters cannot separate the taxa, and say so in the legend. Describe the three to the cladogram maker as one group with no further nesting and it draws the polytomy instead of guessing.
A table where every character maps to exactly one node is perfectly consistent, and textbook exercises are built that way on purpose. Real datasets are not, which is why phylogenetics software reports a consistency index and why the cladogram maker flags a conflict rather than hiding it.
Where are cladograms used?
Worksheets, revision notes and lab reports
Worksheets, revision notes and lab reports for evolution units. Give the cladogram maker the character table and get the matrix and the diagram in one figure, or a whiteboard version for the lesson itself.
Lectures & science communication
The illustrated style puts an organism at every tip, which is what a slide or an explainer needs. It is the kind of figure phylogenetics software will not draw and the cladogram maker produces in one pass.
Papers, theses & posters
Clean rectangular trees with exact taxon names and clade labels for a background section, a review or a poster panel. The cladogram maker takes the group name and you skip tree-drawing software and the data file.
From the cladogram maker to the page
The cladogram maker exports at 1K by default, which is enough for a single-column journal figure at 300 dpi, a worksheet printed at A4, and any slide. Go to 2K when the tree has more than ten tips or sits across two columns, and 4K for a poster panel.
Which size to export
| Destination | Export | Why |
|---|---|---|
| Worksheet or handout, A4 | 1K, 16:9 or 3:2 | Prints at roughly 240 dpi across the page; labels stay legible at 10 pt |
| Lecture slide, 16:9 | 1K from the cladogram maker | Screens never need more; the illustrated style reads best here |
| Journal figure, one column | 1K, upscale if the journal asks for 600 dpi | Most author guides want 300 dpi for line art at 85 mm width |
| Two-column figure or poster | 2K or 4K | Twelve-plus tips at 180 mm need the extra pixels for the taxon names |
Taxon names are the first thing to fail at small sizes, so the cladogram maker sets them at a fixed minimum height. If a name still wraps, shorten it to the genus or ask for the rectangular style, which gives the labels the full right margin.
Writing the figure legend
A cladogram legend states four things: what the tree shows, where the topology comes from, what the marks on the branches mean, and that branch lengths carry no information. Reviewers ask for the last two more often than authors expect. The cladogram maker gives you the topology and the marks; the words are yours, and this template covers them.
Figure 2. Cladogram of the five vertebrate groups used in this study. Topology follows the character matrix in Table 1, rooted on the lamprey as outgroup. Tick marks indicate the node at which each derived character first appears. Branch lengths are arbitrary and do not represent time or amount of change. Tree drawn with the Scientific Figure cladogram maker.
Cladogram maker, generator, creator or builder?
Searches use all four words for the same kind of tool, and the pages that answer them do the same job: turn a list of taxa or a character table into a drawn tree. Where there is a working distinction, a cladogram generator usually means something that takes a table and derives the topology, while a cladogram maker or creator may only lay out a tree you already know. This one does both, so whichever word brought you here, the steps above apply.
Common questions about the cladogram maker
How does the AI cladogram generator work?
You describe the group in plain language. The cladogram maker first works out the nested clades, which taxa form each group and what derived character marks each node, then draws the tree with your exact taxon names at the tips. Give it just a group name and it uses the currently accepted phylogeny; give it a character matrix and it builds the tree that data implies.
Can the cladogram maker build a tree from a character table?
Yes, and it is the job it does best, so if you arrived looking for a cladogram generator from a table, this is it. Paste the table and pick the Tree + character matrix style: the taxon with the fewest derived characters becomes the outgroup, each character labels the node where it first appears, and the finished figure shows the tree beside the matrix it came from.
Can the cladogram maker read Newick, or a tree I have already worked out?
Yes. Paste a Newick string or simply write the topology out, and the cladogram maker draws it exactly as specified rather than correcting it to the textbook version. If what you asked for conflicts with the accepted phylogeny, the diagram follows your instruction and the note in your workspace says so.
Is the cladogram maker a phylogenetics package?
No. It makes tree figures for teaching, publications, slides and articles, not phylogenetic inference. If you need a tree estimated from sequence data with support values, use MEGA, RAxML, IQ-TREE or iTOL; if you need a clean, correct cladogram in about a minute, the cladogram maker is the faster path. The comparison table above sets the two side by side.
What is the difference between a cladogram and a phylogenetic tree?
Every cladogram is a phylogenetic tree, but it shows branching order alone; its branch lengths are arbitrary. A phylogram scales branch length to the amount of evolutionary change and a chronogram scales it to time. Cladograms are what teaching material and most conceptual figures use, because the relationships are the point. The cladogram maker draws the first kind only.
Is the cladogram maker free? Can I use the diagrams commercially?
You can use the cladogram maker on the free plan, with a watermark on exports. Paid plans remove the watermark and unlock every model and high-resolution export, and you can use your diagrams in courses, publications and commercial material.
How do you read a cladogram?
Read it at the nodes, not across the page. Two tips are close relatives if the node joining them is near the tips, and distant relatives if you have to travel down to the root to connect them, regardless of how near each other they are printed. Tips are not ranked left to right, and no living tip is more evolved than another: every one has had the same time since the root. The cladogram maker prints tips flush at the right for exactly this reason.
What is a clade?
A clade is one node on the tree plus every descendant of that node, with nothing left out. Birds and crocodiles plus their common ancestor form a clade; "reptiles" as usually meant does not, because it excludes birds while including their ancestor. A group that leaves out some descendants is paraphyletic, and a group assembled from unrelated branches is polyphyletic; neither is a clade. Ask the cladogram maker to label a clade and the label lands at the node, never on a region of the page.
What is an outgroup and why does a cladogram need one?
The outgroup is a taxon known to lie outside the group you are studying; it is what tells you which character states are ancestral and therefore where the root goes. Without an outgroup a branching pattern has no direction: the same tree could be rooted in several places and would then say quite different things about who is related to whom. Name the outgroup in your prompt and the cladogram maker roots the tree on it.
What does a node on a cladogram mean?
A node is the most recent common ancestor of everything above it. It is a hypothesis, not a fossil: it stands for an ancestral population that the character evidence implies existed, and it usually has no name and no specimen attached to it. The cladogram maker leaves nodes unnamed unless you give them a clade name.
What is a synapomorphy?
A synapomorphy is a derived character shared by all members of a clade because it first appeared in their common ancestor: feathers for birds, or a four-chambered heart for birds and crocodiles together. Synapomorphies are the evidence for the grouping; characters that are simply ancestral, or that evolved separately, are not. In the teaching-ladder style the cladogram maker writes each synapomorphy beside the branch where it first appears.
How do I make a cladogram from scratch?
Start with a character table: taxa down the side, characters across the top, with the outgroup included. The taxon sharing fewest derived characters with the rest branches off first, and each further derived character marks the next node. Paste that table into the cladogram maker and the tree is built from it directly, or describe the group in words and the currently accepted phylogeny is used instead. The worked example above walks through a five-taxon table.
Can two cladograms that look different show the same relationships?
Yes, and this is the most common way of misreading them. The branches at any node can be rotated freely, and the same tree may be drawn rectangular, slanted or as a ladder. Two diagrams that look nothing alike can be identical trees; only the nesting of the nodes carries information. Rotate any node in the cladogram maker's workspace and the tree it states does not change.
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From a list of organisms to a publication-ready tree in about a minute, inside the cladogram maker.
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