Genetics and conservation biology: assessing historical gene flow in Aquilegia populations of the southwest

摘要: One important demographic process influencing the management of rare plant species is the degree to which geographically distinct populations are interconnected by gene flow. If populations are highly integrated by seed dispersal, a newly extinct one may become recolonized naturally; if populations are essentially isolated from each other, active intervention may be required to reestablish populations. The most tractable means of obtaining information on the rate of migration is based on genetic observations. The genetic approach is also the only means to estimate long-term rates of migration. Unfortunately, the same genetic pattern can arise by the presence of ongoing gene flow or in its complete absence. Using information on chloroplast DNA sequence variation in Aquilegia, we have been able to distinguish between these two possibilities and demonstrate that virtually no seed-mediated gene flow interconnects distinct populations.