The Origin of the Legumes is a Complex Paleopolyploid Phylogenomic Tangle Closely Associated with the Cretaceous–Paleogene (K–Pg) Mass Extinction Event

• DOI: 10.1093/sysbio/syaa041
• Publication Date: 2020-05-26T19:11:07Z
• Authors: Erik J M Koenen; Dario I Ojeda; Freek T Bakker; Jan J Wieringa; Catherine Kidner; Olivier J Hardy; R Toby Pennington; Patrick S Herendeen; Anne Bruneau; Colin E Hughes
• Keywords: Tangle; Paleogene; Extinction (optical mineralogy)

Abstract The consequences of the Cretaceous–Paleogene (K–Pg) boundary (KPB) mass extinction for evolution plant diversity remain poorly understood, even though evolutionary turnover lineages at KPB is central to understanding assembly Cenozoic biota. apparent concentration whole genome duplication (WGD) events around may have played a role in survival and subsequent diversification lineages. To gain new insights into origins biodiversity, we examine origin early globally diverse legume family (Leguminosae or Fabaceae). Legumes are ecologically (co-)dominant across many vegetation types, fossil record suggests that they rose such prominence after parallel with several well-studied animal clades including Placentalia Neoaves. Furthermore, multiple WGD hypothesized occurred evolution. Using recently inferred phylogenomic framework, investigate placement WGDs during using gene tree reconciliation methods, count data phylogenetic supernetwork reconstruction. 20 calibrations estimate revised timeline based on 36 nuclear genes selected as informative evolving an approximately clock-like fashion. establish timing also date nodes trees. Results suggest either pan-legume event stem lineage family, allopolyploid involving (some of) earliest within crown group, additional nested subtending subfamilies Papilionoideae Detarioideae. Gene methods do not account allopolyploidy be misleading inferring earlier time divergence two parental polyploid, suggesting scenario more likely. We show age legumes dates Maastrichtian Paleocene that, apart from Detarioideae WGD, paleopolyploidy close KPB. conclude followed complex history, which auto- and/or coincided rapid association KPB, ultimately underpinning success Leguminosae Cenozoic. [Allopolyploidy; boundary; Fabaceae, Leguminosae; paleopolyploidy; phylogenomics; events]