Answer:
In species with polyploid, there are more chromosomal sets than in diploid one. Becouse there are more chromosomal structures available, events like mutation, recombination, DNA lose, are more probable to occur.
As the generations pass, the accumulation of these changes tend polyploid to speciation.
Remember the cell theory by Virchow that states that all cells come from pre existing cells, if a single cell dies, it can be replaced unless it's a brain cell.
