New molecular marker methods based upon naturally occurring transposable genetic elements have been developed for biodiversity estimations and genetic linkage analysis in tobacco, maize, barley, brassica and field pea. A rapid and simple method has been developed for adapting the marker approach to any plant species. A new high-throughput marker technology, which is based upon the new markers, has been developed. This approach can in principle be applied to all plant species and can potentially score thousands of individuals in approximately 36 hours. A robust method has been developed for unambiguous determination of phylogeny within plant species lineages. In the same way that occasional chromosome rearrangements allow the tracing of ancient phylogenetic relationships, the far more common class I TE-associated perturbations have allowed the dissection of the fine structure of species relationships within the Brassica genus.