Genetic and molecular mechanisms of heterosis in equids and catfish 

Heterosis, first reported by Charles Darwin, is the phenomenon in which hybrids demonstrate superior traits compared to their parents. It is colloquially known as “hybrid vigor”, but scientifically it is defined as the superiority of hybrids in production traits over the parental mean, which is formally computed by the average of the reciprocal hybrid F1s minus the parental mean divided by the parental mean.