The draft of the human genome project reveals an unexpected distribution of Alu interspersed repetitive sequences . This has been interpreted as evidence that Alu sequences 'may benefit their human hosts'  and that they 'have a positive function' . The implication is that the majority of Alu sequences increase the Darwinian fitness of their… (More)
Mobile DNAs are potent sources of mutation in wild populations, but seem only rarely to have been used in adaptive evolution. A new study has revealed a mobile DNA insertion in Drosophila simulans that is associated with an apparent selective sweep and an elevation in expression level of an adjacent gene which creates insecticide resistance.
What are they? They occur when a wild population is reduced to a small number of individuals, and then increases again. They are typically caused by an environmental change such as unusual climatic conditions, or, increasingly, the actions of humans, as in over-hunting and habitat destruction. But if the population size is restored, everything ends up fine,… (More)
The vast amount of information being gathered about human DNA sequence variation raises the question of what these data can tell us about events in our past. A new way has been found by which patterns of linkage disequilibrium can be used to detect the effects of natural selection in human prehistory.