Summary
Body parts with similar structure from a common ancestor but different functions, like a human arm and bat wing.
In depth
The forelimbs of humans, cats, whales and bats contain the same bones (humerus, radius, ulna, carpals, metacarpals, phalanges) modified for different uses. This pattern is best explained by inheritance from a common ancestor and is called adaptive radiation of the pentadactyl limb.
Embryonic similarities also show homology, such as pharyngeal arches in all vertebrates.
Remember: homology means shared ancestry; analogy means shared function.
Frequently asked questions
What is Homologous Structures?
Body parts with similar structure from a common ancestor but different functions, like a human arm and bat wing.
Which area of biology covers Homologous Structures, and how advanced is it?
Homologous Structures is one of the 53 topics in Evolution. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Common Ancestry, Analogous Structures, Divergent Evolution.
What should I learn before Homologous Structures?
Homologous Structures is a Beginner topic, so no earlier topic is required. Other Beginner topics in Evolution that pair well with it include Evolution, Natural Selection, Charles Darwin.
What topics are related to Homologous Structures?
The closest topics to Homologous Structures are Common Ancestry, Analogous Structures, Divergent Evolution, Vestigial Structures. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Homologous Structures?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Homologous Structures. To practise the whole of Evolution, use the Evolution quiz.
How is Homologous Structures different from Common Ancestry?
Homologous Structures: Body parts with similar structure from a common ancestor but different functions, like a human arm and bat wing. Common Ancestry: All living things descend from shared ancestors, evidenced by universal DNA and genetic code. Read both side by side and note what each one explains.
How should I study Homologous Structures 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 Common Ancestry and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.