Final answer:
Mobile genetic elements like transposons contribute to gene duplication and exon shuffling by serving as targets for homologous recombination, leading to an increase in genetic diversity and evolutionary adaptability.
Step-by-step explanation:
Mobile genetic elements, such as transposons, play a significant role in promoting gene duplication and exon shuffling. These elements can contribute to genetic diversity by serving as targets for homologous recombination. In this process, transposons in introns can align similarly to DNA sequences during meiosis, which may lead to unequal recombination. This can facilitate exon shuffling as an exon may be integrated into one gene while being lost from another. Such events can create proteins with new domains and functions, thus increasing species diversity. The resulting genetic variation provided by these mobile elements is a cornerstone of evolutionary change and adaptation, allowing for the development of new phenotypes and enhanced survivability in changing environments.
Among the options provided, the correct mechanism by which mobile genetic elements can promote gene duplication and exon shuffling is A. serving as targets for homologous recombination.