Novel tools for an old lineage: Population genomics for cycads.

With a ca. 300 million year-old evolutionary history, cycads are often perceived as "living fossils," relicts of their previously widespread dominance. Patterns of genetic variation for a member of the most basal cycad genus, Cycas micronesica, support the notion that cycads are a dynamic group with ongoing diversification. Herein we hypothesize that cycad's hefty genomes enable rapid adaptive change and facilitate specific beneficial interactions with varying assemblages of symbionts. Characterizing population-level genomic patterns of cycads and their symbionts, pollinators in particular, will enlighten our understanding of these mechanisms and of adaptive variation that underlies cycad evolution. In light of rapid climate and landscape change, cycads are a beacon for understanding the ecological processes that ultimately enable species long-term survival.