What are the differences between exon shuffling and alternative splicing in terms of their mechanisms and impact on gene expression?

Exon shuffling involves the rearrangement of exons between different genes, leading to the creation of new gene structures. This can result in the formation of novel proteins with new functions. On the other hand, alternative splicing involves the selection of different combinations of exons within a single gene, resulting in multiple mRNA transcripts and protein isoforms from a single gene. This increases the diversity of proteins that can be produced from a single gene, allowing for more complex regulation of gene expression.