Summary
Branching diagrams showing patterns of shared derived traits among taxa.
In depth
Nodes mark common ancestors; a trait table is used to build them. Parsimony picks the tree with the fewest changes. Outgroups root the tree.
A cladogram shows branching order not time. Nodes are hypothesised ancestors. Multiple equally parsimonious trees may exist.
Key idea: more shared derived traits means closer relationship.
A cladogram is a branching diagram that shows the order of divergence among taxa based on shared derived characters. Branch lengths usually carry no information about time or amount of change, unlike a phylogram (length proportional to change) or a time tree (chronogram).
Reading a cladogram means tracing back to nodes: two taxa are more closely related if they share a more recent common ancestor, regardless of which is drawn closer on the page, since branches can rotate around nodes. An outgroup, a relative outside the group of interest, roots the tree. Characters are listed in a matrix and coded as present or absent.
Example: a cladogram of vertebrates shows jaws, lungs, limbs, amnion and hair arising in sequence.
Key idea: nodes are hypotheses of ancestry, not a ladder of progress.
Frequently asked questions
What is Cladograms?
Branching diagrams showing patterns of shared derived traits among taxa.
Which area of biology covers Cladograms, and how advanced is it?
Cladograms is one of the 52 topics in Taxonomy & Biodiversity. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Shared Derived Characters, Phylogenetic Classification, Monophyletic Groups.
Can you give an example of Cladograms?
A table of traits (jaws, lungs, limbs, hair) can construct a vertebrate cladogram.
What should I learn before Cladograms?
Work through the Beginner topics in Taxonomy & Biodiversity first, such as Taxonomy, Binomial Nomenclature, Taxonomic Hierarchy, then return to Cladograms. Intermediate topics assume the Beginner vocabulary.
What topics are related to Cladograms?
The closest topics to Cladograms are Shared Derived Characters, Phylogenetic Classification, Monophyletic Groups, PhyloCode. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cladograms?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cladograms. To practise the whole of Taxonomy & Biodiversity, use the Taxonomy & Biodiversity quiz.
How is Cladograms different from Shared Derived Characters?
Cladograms: Branching diagrams showing patterns of shared derived traits among taxa. Shared Derived Characters: Novel traits inherited from a recent common ancestor that define a clade. Read both side by side and note what each one explains.
How should I study Cladograms step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Shared Derived Characters and explain the difference aloud. Finally, take the Taxonomy & Biodiversity quiz and come back to this page for any question you miss.