Systemic Genomic Transposition: A Mechanism for Saltational Evolution

The modern evolutionary synthesis is built upon the foundation of Darwinian gradualism: the idea that evolution proceeds through the slow accumulation of minor, incremental mutations. However, this model has struggled to explain sudden bursts of morphological novelty in the fossil record, such as the Cambrian Explosion. A new theory, based on research into extremophile bacteria, proposes a mechanism for massive, instantaneous evolutionary change known as Systemic Genomic Transposition (SGT). This process allows an organism’s genome to undergo a radical restructuring in a single generation—a true quantum leap in genetic terms.

The mechanism is driven by a class of retrotransposons, or “jumping genes,” that remain dormant under normal conditions. However, when the organism is subjected to extreme environmental stress—such as a sudden spike in temperature or radiation—specific “initiator codons” are activated. This single, small change does not trigger a minor mutation. Instead, it unleashes a cascade reaction that causes hundreds or thousands of mobile genetic elements across the entire genome to excise and re-insert themselves in new locations simultaneously. This genome-wide reshuffling results in big outcomes, most of which are lethal.

In exceedingly rare instances, however, the new genomic architecture is viable, producing an organism with radically different traits. SGT is a high-risk evolutionary gamble, but it provides a plausible genetic mechanism for saltational evolution—the abrupt appearance of new forms. Research on the bacterium Pyrococcus furiosus, which thrives near deep-sea hydrothermal vents, has shown that its genome is rife with the molecular machinery for SGT, suggesting that life in harsh, unstable environments may have evolved this remarkable capacity for rapid, revolutionary change.