Cladistics Worksheet
Explore the principles of cladistics, phylogenetic trees, and the classification of organisms based on shared derived characteristics.
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Cladistics: Understanding Evolutionary Relationships
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Read each question carefully and provide your best answer. Refer to your knowledge of cladistics and evolutionary relationships.
1. Which of the following best describes a cladogram?
A diagram showing feeding relationships in an ecosystem.
A phylogenetic tree that illustrates evolutionary relationships based on shared derived characteristics.
A chart that categorizes organisms based on their habitats.
A graph tracking population growth over time.
2. What is a 'shared derived character' (synapomorphy) in cladistics?
A trait found in all organisms being studied.
A trait unique to one specific organism in the group.
A trait that evolved in the common ancestor of a group and is shared by its descendants.
A trait that developed independently in different lineages.
3. The principle of suggests that the simplest explanation for evolutionary relationships is usually the correct one.
4. A group that includes a common ancestor and all of its descendants is called a group.
5. A character state that is ancestral to the group is known as a .
6. Explain the difference between a homologous character and an analogous character in the context of cladistics.
7. All phylogenetic trees are cladograms.
True
False
8. Outgroups are used in cladistic analysis to help determine the ancestral and derived states of characters.
True
False
9. Observe the cladogram below and answer the following questions:
a) Which two organisms are most closely related?
b) What is the common ancestor of all organisms shown in this cladogram?