Restoration of genetic variation lost - The genetic rescue hypothesis

It has been long known that immigrants from surrounding populations might p revent the extinction of small populations, st process known as the 'rescue effect: This focuses on the demographic effects of migration through the d irect positive influence that immigrants have on abundance of the recipient population. Now, two recent papers have indicated another potentially impo rtant way that migration might rescue populations from extinction - repleni shing genetic variation and reducing inbreeding depression, or what has bee n termed 'genetic rescue'.