Are there any mammals in which polyspermy produces viable zygotes? In the wikipedia page it is mentioned that there is a delicate equilibrium between female defenses against many sperms, which ocassionally results in low fertility rates (which in not all cases might be an evolutionary disadvantage, but i disgress)
My question is if there are cases where a ovum can be fertilized by several sperms, and the zygote somehow manages to select fairly between a subset of all chromosomes, avoiding polyploidy and producing a viable embryo.
