Rapid Diversification of a Species-Rich Genus of Neotropical Rain Forest Trees

• Published in: Science (American Association for the Advancement of Science) Vol. 293; no. 5538; pp. 2242 - 2245
• Main Authors: Richardson, James E., Pennington, R. Toby, Pennington, Terence D., Hollingsworth, Peter M.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 21.09.2001; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: America; Biodiversity; Biological and medical sciences; Biological diversity; Biological Evolution; Biological taxonomies; Branches; Central America; Chorology; classification; Deoxyribonucleic acid; DNA; DNA, Chloroplast; DNA, Chloroplast - genetics; DNA, Plant; DNA, Plant - genetics; DNA, Ribosomal Spacer; DNA, Ribosomal Spacer - genetics; Ecosystem; Evolution; Fabaceae; Fabaceae - classification; Fabaceae - genetics; Fabaceae - growth & development; Fossils; Fundamental and applied biological sciences. Psychology; Genera; Genes, Plant; genetics; geographical distribution; growth & development; Individualized Instruction; Inga; Inga (Fabaceae); Numbers; Parsimony; Phylogeny; Plant cytology, morphology, systematics, chorology and evolution; Plants; Plants, Medicinal; Rain forest plants; Rainforests; South America; Speciation; Species diversity; Taxa; Time; Trees; Trees (Plants); Trees - classification; Trees - genetics; Trees - growth & development; Tropical Climate; Tropical plants; Tropical rain forests; America; South America; Central America; Neotropical Region; Climate; Genetic marker; Quaternary; Rain forest; Tertiary; Ribosomal DNA; Spacer DNA; Tropical forest; Phylogeny; Leguminosae; Geographic distribution; Dicotyledones; Angiospermae; Spermatophyta; Species richness; Speciation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1061421

Species richness in the tropics has been attributed to the gradual accumulation of species over a long geological period in stable equatorial climates or, conversely, to speciation in response to late Tertiary geological events and unstable Pleistocene climates. DNA sequence data are consistent with recent diversification in Inga, a species-rich neotropical tree genus. We estimate that speciation was concentrated in the past 10 million years, with many species arising as recently as 2 million years ago. This coincides with the more recent major uplifts of the Andes, the bridging of the Isthmus of Panama, and Quaternary glacial cycles. Inga may be representative of other species-rich neotropical genera with rapid growth and reproduction, which contribute substantially to species numbers in the world's most diverse flora.