What is the term for mobile genetic material that might have supported post-Flood speciation?

The correct term that refers to mobile genetic material which could have played a significant role in post-Flood speciation is "AGE." This term is often associated with the concept of "Adaptive Genetic Elements," which include various forms of mobile genetic elements such as transposons or plasmids. These elements can facilitate the adaptation and rapid evolution of organisms by allowing for the transfer of genes between different species or within populations. This genetic mobility and adaptability would be particularly relevant in a post-Flood scenario, where rapid environmental changes and the need for new species to emerge could drive speciation processes.

In contrast, while DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are fundamental to all forms of life and represent the genetic blueprint and expression in organisms, they do not encompass the specific dynamics implied by the term concerning mobile genetic material that enhances variability and adaptability. The term "GEN" is more abstract and does not specifically refer to genetic mobility in the context required by the question. Thus, "AGE" is most fitting for the context of mobile genetic material supporting speciation after significant environmental changes.