NEWS AND COMMENTARY

search, extensive genomic analysis and statistical modelling. The questions 'from where?' and 'when?' are ad- dressed and variation in NRYs used to provide answers in circumstances where other sources of information are not available. It is as much the virtual absence of 'African type' NRYs from the British survey as the presence of the one identified that contributes to our under- standing of when and by whom this corner of the world was peopled. The researchers are also to be com- mended for the circumspection with which they interpret their results. They accept, for example, that the 'African type' chromosome studied may have been introduced into Britain at some indeterminate time in the past, before 1734. For all we know it could have been introduced with the wave of