Given what is known about the TE content of the D. melanogaster genome, such a high rate of invasions during this time is unexpected and must be inflated relative to the species´ broader evolutionary history. Pianezza et al. (2024) hypothesize that this is linked to human activity, specifically global trade, as D. melanogaster is a human commensal with a cosmopolitan range that has recently been brought into secondary contact with other drosophilids, e.g., the neotropical D. willistoni. If this hypothesis holds, we expect that other insect species – specifically those who have recently become cosmopolitan – may also have an inflated rate of recent TE invasions.
We want to test this hypothesis by sequencing and investigating the genomes of historical specimens from a range of different species. For this purpose, I have developed a protocol for non-destructive DNA extraction that causes only minimal physical changes while the captured quantity of DNA is sufficient for whole genome sequencing. At this point we have established collaborations with three institutions – the monastery Stift Seitenstetten, the Natural History Museum of Vienna and the Smithsonian National Museum of Natural History – and extracted DNA from 86 individuals across ten species.