Teaching evolution using a card game: negative frequency-dependent selection

Abstract

Teaching biological evolution can be difficult on a number of levels, be it student confusion arising from prior conceptions and the controversy surrounding evolution, or simply because the material is complex. Games and simulations can help to convey complex topics and also to increase variety in teaching methods. Here I describe a card game that can be used to teach the advanced topic of protected polymorphism in higher education settings. Protected polymorphism is allelic variation resulting from negative frequency-dependent selection; when the fitness of an allele increases when it becomes rare, the allele will be ‘protected’ from extinction. Negative frequency-dependent selection is proposed to maintain genetic variation in nature, which is required for evolution by natural selection. Protected polymorphisms primarily play a role in biological interactions, such as immune systems, plant-pathogen interactions, sexual selection and predator-prey interactions. The card game described here uses plant pollination alleles as an example. The game is played using eleven stocks of traditional playing cards per group of about six students. Specific topics addressed include negative frequency-dependent selection, polyploidy, dominance, selfing and inbreeding depression.