Inbreeding is the mating or breeding of individuals who are closely related genetically, such as siblings, cousins, or other relatives who share common ancestors. This process results in offspring that have increased homozygosity, meaning they inherit identical copies of genes from both parents due to their shared ancestry. While inbreeding can help retain desirable traits or establish specific characteristics in animals or plants, it also raises the risk of expressing harmful recessive genetic traits. This can lead to genetic disorders, reduced fertility, decreased survival, and overall lowered biological fitness, a condition known as inbreeding depression. In populations where inbreeding is frequent, there may be an accumulation of genetic defects and increased susceptibility to inherited diseases. Inbreeding is measured by coefficients that estimate the probability of genes being identical by descent. It is common in selective breeding but requires careful management to avoid negative health and genetic consequences.