Have a fling with your neighbour, you might be less related.

Major threats to biodiversity and ecosystem persistence are fragmentation of habitats and declining population sizes. For conservation biologists to understand the consequences of declining populations for the long term persistence and recovery of species worldwide, it is important to know and understand the underlying causes of potential threats, such as the depletion of genetic diversity, which is important for populations to be able to adapt and prevail in a changing environment. One of the major threats is the risk of inbreeding, which might decrease the genetic diversity substantially in a population. It has long been notoriously hard to collect good pedigree data in wild populations, but with the continuous development of molecular methods, it has become possible to estimate inbreeding by using molecular markers, such as microsatellites and single nucleotide polymorphism (SNPs). These estimates of inbreeding have proven to be immensely valuable when studies of the consequences of inbreeding are conducted, from studies of inbreeding avoidance behavior to population fragmentation, but also in speciation and evolution. In this monograph, a collection of studies show different applications of molecular estimates of inbreeding and also discuss the pros and cons with the different methods and analysis following the estimation. The studies cover genome evolution, inbreeding avoidance, speciation and island theories using manly the blue tit (Cyanistes caeruleus) as a study organism.