Some Advantages Of Hybrid Vigor (Heterosis)

When previously isolated populations meet and mix, the resulting admixed population can benefit from several genetic advantages, including increased genetic variation, the creation of novel genotypes and the masking of deleterious mutations.

-- Koen J. F. Verhoeven, Mirka Macel, Lorne M. Wolfe and Arjen Biere

from "Population admixture, biological invasions and the balance between local adaptation and inbreeding depression"

Quoted on Sat Jun 25th, 2011