Populations spaced further apart are expected to be more genetically distinct than populations close together. This pattern arises because neighbouring populations exchange genes.
The trend can be used to infer the magnitude of gene flow.
François Rousset has written papers showing how to calculate such estimates but some researchers – especially plant geneticists – use rival methods based on the statistic “Moran’s I”. Rousset explains why his methods are an advance on these alternatives in a recent News and Commentary published in Heredity.
Click here to read the Heredity News and Commentary