Final answer:
Metapopulations are systems of separate populations connected by the exchange of individuals between habitat patches, which may help prevent local extinctions and promote genetic diversity.
Step-by-step explanation:
Subpopulations living in specifically isolated patches connected by the exchange of individuals among patches are called a metapopulation. A metapopulation consists of separate populations of the same species that are divided into discrete habitats (patches), which may have varying degrees of interaction or exchange of individuals between them. The viability of these populations typically increases with the interconnectedness of these patches, as it allows for recolonization and gene flow, which can prevent local extinctions and promote genetic diversity.
One specific type, described as the mainland-island model, features a large 'mainland' population that serves as a reservoir of individuals that can migrate to and bolster smaller 'island' populations. Another form is an equally vulnerable network of populations, where each patch could potentially go extinct, but the overall metapopulation persists over time due to recolonization from surviving patches.