[Campbell Biology P.505] Figure 21.14 notes that 'The gold elements are pseudogenes. Explain... | Practice Question
Figure 21.14 notes that 'The gold elements are pseudogenes. Explain how they could have arisen after gene duplication.' Based on the provided text, which of the following best explains the origin of pseudogenes in the context of globin gene evolution?
A: Pseudogenes are ancestral genes that were never duplicated and gradually lost their function due to lack of selective pressure.
B: After gene duplication, some duplicated copies accumulated random mutations over evolutionary time that destroyed their original function, rendering them non-functional 'pseudogenes' while other copies retained function.
C: Pseudogenes are formed when a gene is transposed to a different chromosome, causing it to lose its regulatory elements and become inactive.
D: Pseudogenes are gene copies that performed novel functions beneficial to the organism, leading to their preservation without the original function.
Explanation
The text states: 'The existence of several pseudogenes among the functional globin genes provides additional evidence for this model: Random mutations in these 'genes' over evolutionary time have destroyed their function.' This directly explains how duplicated genes can become pseudogenes.