Cladistics

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/cladistics

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the methodology?Hypothesis-driven classification based on shared derived characteristics and common ancestry
2. What is the core unit?Clades, defined as monophyletic groups including an ancestor and all its descendants
3. What is a clade?A clade is a group that includes an ancestor and all of its descendants, like a whole branch of the tree of life.
4. How do scientists decide which animals belong together in a cladogram?Scientists look for shared derived traits, called synapomorphies, that only appear in a group because they were passed down from a single ancestor.

Cladistics: A systematic method for inferring evolutionary relationships among organisms based on shared derived characteristics.
Clade: A monophyletic group comprising an ancestral lineage and all of its descendants.
Synapomorphy: A homologous trait shared by two or more taxa that is derived from a common ancestor unique to that group.
Paraphyletic Group: A group that includes an ancestral taxon but not all of its descendants, thus not representing a complete evolutionary lineage.