Homologous Structures: Evidence for Evolution

What You'll Learn

Homologous structures are similar body parts in different species that suggest a common ancestor. The arm bones of humans, whales, bats, and dogs share the same basic structure.

Key Words

parent
characteristic
feature

Materials Needed

microscope (or magnifying glass)
slides
onion skin
iodine stain

Safety First

Adult supervision recommended.

Steps

Step 1 — Read

Read about Inheritance and Traits and write down three key facts.

Step 2 — Do

Research one genetic disorder. Create an infographic showing its cause, symptoms, and how it is inherited.

Step 3 — Observe

Watch carefully for any changes and note the time.

Step 4 — Record

Create a data table to organize your measurements.

Check Your Understanding

Question 1

1 of 3

What are homologous structures?