title: Plant evolution: pulses of extinction and speciation in gymnosperm diversity.
abstract: Living gymnosperms represent the survivors of ancient seed plant lineages whose fossil record reaches back 270 million years. Two recent studies find that recent pulses of extinction and speciation have shaped today's gymnosperm diversity, contradicting the widespread assumption that gymnosperms have remained largely unchanged for tens of millions of years.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Herbaria, Cambridge, MA 02138, USA. cdavis@oeb.harvard.edu
authors.forename: Charles C
authors.initials: CC
authors.lastname: Davis
authors.forename: Hanno
authors.initials: H
authors.lastname: Schaefer
mesh_terms: D044822:Biodiversity; D005075:Biological Evolution; D057231:Climate Change; D032462:Cycadopsida / Q000235:genetics* / Q000502:physiology; D053476:Extinction, Biological; D005580:Fossils; D017343:Genes, Plant; D049810:Genetic Speciation; D019684:Magnoliopsida / Q000235:genetics / Q000502:physiology; D010802:Phylogeny; D013997:Time Factors