Summary
Extra gene copies free one copy to acquire new functions, fuelling evolutionary innovation.
In depth
Duplicates can arise by unequal crossing over, retrotransposition or whole-genome duplication. One copy retains function, while the other may acquire a new function (neofunctionalisation), split functions (subfunctionalisation) or be lost.
Globin genes are a classic family from duplications.
Susumu Ohno proposed that duplication is a major source of new genes (1970). After duplication, outcomes are loss of one copy (most common), subfunctionalisation (the copies split the original roles), neofunctionalisation (a new role) or retention for dosage. The globin family arose by duplications, giving haemoglobin chains and myoglobin, and the opsin duplication in primates gave trichromatic colour vision.
Whole-genome duplications occurred twice in early vertebrates, giving four Hox clusters in mammals, and in many plants. Amylase gene copy number varies in humans and correlates with starch consumption. Unequal crossing over also leads to disease, for instance in colour blindness and Charcot-Marie-Tooth disease.
Example: duplicated Hox clusters in teleost fish gave seven or eight, associated with fin diversity.
Frequently asked questions
What is Gene Duplication?
Extra gene copies free one copy to acquire new functions, fuelling evolutionary innovation.
Which area of biology covers Gene Duplication, and how advanced is it?
Gene Duplication is one of the 53 topics in Evolution. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Adaptive Radiation, Homologous Structures, Molecular Clock.
Can you give an example of Gene Duplication?
Vertebrates experienced two rounds of whole-genome duplication.
What should I learn before Gene Duplication?
Work through the Beginner topics in Evolution first, such as Evolution, Natural Selection, Charles Darwin, then return to Gene Duplication. Advanced topics assume the Intermediate vocabulary.
What topics are related to Gene Duplication?
The closest topics to Gene Duplication are Adaptive Radiation, Homologous Structures, Molecular Clock, Vestigial Structures. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Gene Duplication?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Gene Duplication. To practise the whole of Evolution, use the Evolution quiz.
How is Gene Duplication different from Adaptive Radiation?
Gene Duplication: Extra gene copies free one copy to acquire new functions, fuelling evolutionary innovation. Adaptive Radiation: Rapid diversification of a lineage into many forms filling different niches, as with Hawaiian honeycreepers. Read both side by side and note what each one explains.
How should I study Gene Duplication 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 Adaptive Radiation and explain the difference aloud. Finally, take the Evolution quiz and come back to this page for any question you miss.