Polyploidy occurrences

Polyploidy occurs when two complete genomes from each of two parents, potentially of differing species, merge to form an offspring with four total copies of that/those genome/genomes. Polyploid is common in flowering plants and seems to give rise to important evolutionary innovations. However, it is unstable, and descendants of polyploid founders rapidly lose many of their duplicate genes. Previous analyses have argued that the losses tend to favor one of the parental genomes: however, methodological concerns have led to some doubt on this point.  By modeling the resolution of these three polyploidy events across 21 genomes (10 plants and 11 yeasts), we confirm the existence of this bias in loss patterns and present new data to suggest that one source of the bias is selection to maintain function in co-adapted complexes from the alternative parental genomes.