Invasive alien species (IAS) are one of the leading causes of biodiversity loss, especially in the case of islands. Although representing only 5.3% of the Earth's land mass, islands are linked to 75% of the extinctions of birds, amphibians, mammals, and reptiles worldwide. Traditional tools to control IAS, such as toxicants, can be excessively costly, geographically limited and have off-target effects.
Gene drive technologies can potentially offer an alternative method to reduce biodiversity loss. In a recent study, scientists explored a solution to address the potential impact of gene drive on non-target populations if a drive-bearing individual escapes from the delimited area. In the case of islands that exhibit significant genetic isolation from neighbouring populations, researchers suggested the use of an approach targeting "locally fixed alleles". Due to the higher levels of genetic diversity in mainland populations, such an approach would lead to a “highly localized” gene drive system that would spread much less easily (or not at all) through them.
Using mathematical modelling in small island populations of rodents, scientists analysed whether genetic drift would lead to alleles at multiple genomic loci becoming fixed, to determine whether this approach was feasible. They also examined the degree of localization achievable for a gene drive system.