Most DNA is inert, but some DNA sequences are mobile – they can move, or jump, from one location in a genome to another by copy and paste processes. These so-called transposable elements, or “jumping genes”, are important because their activity within genomes gives them the ability to cause a great variety of genetic changes. While this can be harmful to the occasional individual, for example by causing a genetic disorder, overall it is a boon for the evolution of living things because it increases the amount of potentially beneficial genetic variation upon which natural selection can act. Jumping genes are thus not unlike Rumpelstiltskin, the fairytale rascal who was somewhat troublesome yet had the wondrous ability to spin straw into gold.
Jumping genes are ancient and ubiquitous, and are found throughout the animal and plant kingdoms. Long regarded as “junk DNA” by some, they can act over and above other known ways by which DNA mutations occur to make genomes more changeable, thereby boosting their evolutionary potential.
We have recently developed a hypothesis that explains how jumping genes provide an extra “evolutionary boost”. According to the “transposon thrust” hypothesis, jumping genes powerfully promote evolution in one of two major ways.
1. In what we call active transposon thrust, jumping genes make changes to genomes through insertion...
