Determining the whens and hows of biological invasions using genetic data is a major goal of molecular ecology. One such tool is approximate Bayesian computation (ABC) which is being used for inferring invasion histories.
In a new paper in Heredity, Benazzo et al. (2015) present a largely unexplored model of multiple introductions from a single source.
Their scenario posits one invasive population that has established at a single site. After a few generations, a new wave of introduced individuals arrive.
The novel aspect of this model is that the second wave originates from the same source as the first; most models of multiple introductions consider a second wave originating from a geographically and genetically different source than the first.
Using simulated microsatellite data, the power of ABC to distinguish between single and multiple introductions from the same source and under a variety of different demographic parameters was evaluated.
[They] demonstrated that it is often possible, using the inferential power of ABC and under a range of realistic demographic conditions, to distinguish between one or two waves of invasion from the same source, and to infer some important parameters.