The evolution of social inbreeding mating systems in spiders: limited male mating dispersal and lack of pre-copulatory inbreeding avoidance in a subsocial predecessor

Cooperation and group living are extremely rare in spiders and only few species are known to be permanently social. Inbreeding is a key characteristic of social spiders, resulting in high degrees of within-colony relatedness that may foster kin-selected benefits of cooperation. Accordingly, philopatry and regular inbreeding are suggested to play a major role in the repeated independent origins of sociality in spiders. We conducted field...