The reason for this was that the polyandrous females suffered a far lower rate of spontaneous abortion, which occurs when genetic incompatibility between the maternal and paternal genomes results in an immunological conflict between mother and embryo.

ECONOMIST: Polyandry

Jeanne Zeh and her colleagues, who published their results in the current edition of Proceedings of the National Academy of Science, have shown that in a type of arthropod known as a pseudoscorpion, polyandrous females do, indeed, produce more offspring as a direct result of their promiscuity.

ECONOMIST: Polyandry