In the last three to four years, genetic sampling of ancient and modern individuals has led to some real surprises for the world of prehistory. Many migration events that were dismissed as old hat in the 1990s and 2000s have resurfaced as having an actual basis: the Yamnaya-steppe migrations, the early Neolithic migrations and the Bell Beaker migrations into the British Isles. In the last week, a piece of cutting-edge research has upped the game with a ground-breaking new technique called ASCEND , a simulation program which models the effect of population bottlenecks, introgression and boom-bust cycles on the human genome. The science is still tentative - and the paper has yet to receive a sustained review - but its findings are significant. Published in PLOS Genetics, Rémi Tournebize and his academic colleagues looked at the sharing of alleles that often happens during 'founder events', or periods where a population contracts and begins to start anew from a bottom floor. The