摘要：This study examines the evolution of an emerging form of social organization: mixed–mode groups . These are Internet–established but operate as in–person voluntary associations. Through longitudinal observations and interviews with 34 group organizers of Meetup.com, a good example of mixed–mode groups, findings of this study revealed the iterative and simultaneous variation–selection–retention (V–S–R) mechanisms enacted by groups as they evolved. Building on permeable boundaries and multiple memberships, these bona fide groups also exhibited different forms of interaction with other groups as well as the local community.
关键词：mixed modalities;bona fide groups;ecology and evolutionary;social network
