TY - JOUR T1 - Evolutionarily younger and faster diversifying plants are more threatened by extinction JF - bioRxiv DO - 10.1101/152215 SP - 152215 AU - Andrew J. Tanentzap AU - Javier Igea AU - Matthew G. Johnston Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/06/27/152215.abstract N2 - Many species are threatened by extinction, yet few factors have been identified to explain this risk across the plant Tree of Life (ToL). Lineages that are evolutionarily younger or occurring within rapidly diversifying clades may have elevated extinction risk because they occupy smaller geographic ranges and adaptive zones as compared with older lineages that have tolerated longer periods of environmental change. Here we find that faster diversifying plant genera had more species at risk of extinction. Evolutionary age had no effect in the 297 genera that we sampled, potentially because of sampling older genera, on average, from across the ToL. Repeating our analyses in two well-sampled and large groups, we found that extinction risk decreased with evolutionary age in conifer species but not palms. Small sample sizes limited our power to detect effects of lineage diversification in these groups. Our results suggest that contrasting modes of speciation may explain differing patterns of extinction risk across the broader ToL and have consequences for biodiversity conservation. ER -