Hybrid offspring generally possess traits or characteristics seen in ancestral species. These traits might be expected to be subdued or diluted when compared to the original species. Transgressive segregation attempts to explain situations when the converse is true, hybrid offspring that appear to have overstated traits when compared to the parental line.
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..