Transgressive segregation

In biology, studies of hybrid populations sometimes report the presence of traits or phenotypes that are extreme relative to either of the parental lines. The generation of these extreme phenotypes is referred to as transgressive segregation.

Transgressive segregation has been hypothesized as an important mechanism by which novel adaptations observed in hybrids can arise.

There are many mechanisms that could be responsible for transgressive segregation in hybrids such as: an elevated mutation rate, reduced developmental stability, epistatic effects between alleles, overdominance caused by heterozygosity at specific loci or chromosome number variation. .