Final answer:
Gene rearrangement enables the rapid evolution of the immune system by allowing the generation of a vast diversity of antibodies from a limited number of genes, through the recombination of V, D, J, and C regions during B and T cell maturation.
Step-by-step explanation:
Gene rearrangement was a revolutionary concept because it allows for the rapid evolution of the immune system. This concept explains how despite having less than 50,000 genes, the human genome can produce a vast array of antibody molecules, each with unique specificity. The mechanism involves the recombination of multiple variant V (Variable), D (Diversity), and J (Joining) regions linked to a C (Constant) region, allowing for the creation of numerous unique V-D-J-C immunoglobulin antibody molecules. This happens during the maturation of B and T lymphocytes in the bone marrow. Therefore, each B cell ends up producing one type of antibody specific to particular antigens, contributing to the efficiency and effectiveness of the immune response.