“Xenogenesis,” a retrospective of the London-based Otolith Group, opens at Dublin’s Irish Museum of Modern Art (IMMA). Collecting works produced between 2011-18 by Anjalika Sagar, Kodwo Eshun, and collaborators, that cultivate “a science fiction of the present” through media, installation, and performance, the show includes Sovereign Sisters (2014), a CGI short about the Universal Postal Union’s “imperial ambition,” and a special public program curated by the collective.