Inbreeding depression is a reduction in fitness in a given population due to the reproduction of related individuals. This is often the result of a demographic bottleneck. In general, the greater the genetic variation within the population, the less likely it is to marry parents with depression. Inbreeding depression appears to be present in most groups of organisms, but varies among mating systems. Hermaphroditic species often exhibit a lesser degree of inbreeding depression and species hybridization, and repeated generations of self-fertilization are thought to clean out harmful alleles from the population. For example, it has been proven that in filamentous hybridization, some remanei types suffer severely from inbreeding depression, unlike the hermaphrodite relativity of C. elegans, which suffer from inbreeding depression. [1] Crossbreeding between closely related individuals, and called inbreeding, may be the result of one side having more harmful recessive qualities manifest, because the genomes of the pairs are more similar: recessive qualities can only occur in the offspring. if it is present in the genome of both parents, and in more genetically similar parents, recessive traits often appear in their offspring. Thus, more closely related pairs and reproductive and harmful genes may result in more symmetrical offspring, resulting in poorly able-bodied individuals. For alleles that give an advantage to the dominant heterozygous and/or homozygous state, and the fitness to the symmetric-recessive state may be zero (average sterile or non-viable offspring). An example of inbreeding depression on the right. In this case the allele is recessive, which has a negative effect...... middle of paper ...... positions, this is a rare event though, as the genes cannot grow too large (and thus increase the probability of new harmful alleles appearing by mutation) nor too small (resulting in frank inbreeding depression). However, colonization between populations on the island is often considered very resistant to inbreeding depression. This is because the initial population was very small, which should be applicable, and panmixia was in the early stages of generally complete new types. This leads at least to a very complete elimination of harmful recessive alleles. [9] [10] [11] [verification needed] The second type of inbreeding by overdominant heterozygous alleles is impossible to eliminate by panmixia caused by depression. However, local conditions may give rise to a selective advantage in favor of the change, thereby reducing the fitness of the heterozygous genotype . .